Supplier Info: Fabrication Standards (M7-13)

M7-13
FABRICATION STANDARDS
COMMUNICATIONS & POWER INDUSTRIES LLC
MICROWAVE POWER PRODUCTS DIVISION
Revision: AV
ECO: MPP615849
May 16, 2016
Spec. No.: M7-13
FABRICATION STANDARDS
ECO: MPP615849 Rev. AV
Date: May 16, 2016
MANUFACTURING SPECIFICATION
Page i of iii
TABLE OF CONTENTS
PREFACE................................................................................................................................................... 1
REFERENCES ........................................................................................................................................... 1
DEFINITIONS ............................................................................................................................................. 1
1.0
RAW MATERIALS ........................................................................................................................... 2
2.0
STANDARDS FOR RAW-MATERIAL MACHINING ALLOWANCES............................................... 3
3.0
4.0
5.0
6.0
2.1
Minimums ............................................................................................................................. 3
2.2
Calculation of Raw-Material Dimensions............................................................................... 3
2.3
Tubing .................................................................................................................................. 4
CERTIFICATION.............................................................................................................................. 4
3.1
When Certification is Required ............................................................................................. 4
3.2
Delivery or Storage of Certifications ..................................................................................... 4
3.3
Requirements on All Certifications ........................................................................................ 4
3.4
Certification Types ................................................................................................................ 5
PACKAGING AND LABELING ........................................................................................................ 5
4.1
Parts Protection in Packing ................................................................................................... 5
4.2
Transportation ...................................................................................................................... 6
4.3
Package Labeling ................................................................................................................. 7
GEOMETRIC DIMENSIONING AND TOLERANCING SYSTEM ..................................................... 7
5.1
Unspecified Tolerance .......................................................................................................... 7
5.2
Unspecified Finish ................................................................................................................ 8
5.3
Unspecified Flatness ............................................................................................................ 8
5.4
Unspecified Cylindricity ......................................................................................................... 8
5.5
Unspecified Perpendicularity ................................................................................................ 8
5.6
Unspecified Parallelism ........................................................................................................ 9
5.7
Unspecified Concentricity ..................................................................................................... 9
5.8
Unspecified Position ............................................................................................................. 9
5.9
Unspecified Circularity .......................................................................................................... 9
5.10
Unspecified Countersinks ..................................................................................................... 9
TOOLING ...................................................................................................................................... 10
Communications & Power Industries LLC • Microwave Power Products Division • P.O. Box 50750 • Palo Alto • California • 94303-0750
Spec. No.: M7-13
FABRICATION STANDARDS
ECO: MPP615849 Rev. AV
Date: May 16, 2016
MANUFACTURING SPECIFICATION
Page ii of iii
TABLE OF CONTENTS
(continued)
7.0
CLEANING, PLATING, AND COATING OF SURFACES .............................................................. 10
8.0
BURRS .......................................................................................................................................... 10
9.0
10.0
8.1
Definition ............................................................................................................................ 10
8.2
Types.................................................................................................................................. 11
8.3
Height ................................................................................................................................. 11
8.4
Removal ............................................................................................................................. 11
8.5
Edges ................................................................................................................................. 12
8.6
Corners............................................................................................................................... 12
8.7
Sheet Metal ........................................................................................................................ 13
THREADS ...................................................................................................................................... 13
9.1
Internal Threads ................................................................................................................. 13
9.2
Threaded Holes .................................................................................................................. 13
9.3
Threaded Parts ................................................................................................................... 14
9.4
Full-Form Threads .............................................................................................................. 14
9.5
Unspecified Thread Class of Fit .......................................................................................... 14
SHEET-METAL PRODUCTS FABRICATION REQUIREMENTS................................................... 14
10.1
Sheet Metal ........................................................................................................................ 14
10.2
Features and Surfaces ....................................................................................................... 14
10.3
Machined Features ............................................................................................................. 15
10.4
Circular Runout ................................................................................................................... 15
10.5
Washer-Type Punching ...................................................................................................... 15
10.6
Flatness .............................................................................................................................. 15
10.7
Parallelism and Perpendicularity ......................................................................................... 16
10.8
Edges and Corners ............................................................................................................. 16
10.9
Stock Thickness after Forming ........................................................................................... 16
10.10 Breakaway .......................................................................................................................... 17
10.11 Burrs ................................................................................................................................... 17
10.12 Burr Symbols and Drawing Callouts ................................................................................... 18
Communications & Power Industries LLC • Microwave Power Products Division • P.O. Box 50750 • Palo Alto • California • 94303-0750
Spec. No.: M7-13
FABRICATION STANDARDS
ECO: MPP615849 Rev. AV
Date: May 16, 2016
MANUFACTURING SPECIFICATION
Page iii of iii
TABLE OF CONTENTS
(continued)
11.0
12.0
CASTING AND FORGING REQUIREMENTS ............................................................................... 18
11.1
Position............................................................................................................................... 18
11.2
Flatness .............................................................................................................................. 19
11.3
Cleanup .............................................................................................................................. 19
11.4
Mismatch ............................................................................................................................ 19
11.5
Draft ................................................................................................................................... 19
11.6
Repair ................................................................................................................................. 20
EDM FABRICATION REQUIREMENTS ........................................................................................ 20
APPENDIX: Geometric Symbology ............................................................................................... 21
Communications & Power Industries LLC • Microwave Power Products Division • P.O. Box 50750 • Palo Alto • California • 94303-0750
Spec. No.: M7-13
FABRICATION STANDARDS
ECO: MPP615849 Rev. AV
Date: May 16, 2016
MANUFACTURING SPECIFICATION
Page 1 of 21
ATTENTION
UNLESS OTHERWISE SPECIFIED ON THE PURCHASE ORDER(S) OR CPI INTERNAL
SHOP WORK ORDER(S), CONFORMANCE TO ALL REQUIREMENTS OF THE
DRAWING(S) AND SPECIFICATION(S) IS MANDATORY.
PREFACE
The object of the Fabrication Standards Specification M7-13 is to supplement the design information on
CPI drawings for microwave Vacuum Electron Device (VED) assemblies and components. Suppliers and
CPI manufacturing units shall be responsible for the implementation of these standards in the performance
of work for CPI as outlined in CPI purchase orders and shop work orders.
This standard reflects the technical requirements for the Microwave Power Products Division (MPP) of
Communications and Power Industries LLC.
The previous Section 6.0, “Coolants, Lubricants, and Solvents,” which has been a part of past revisions, is
now a separate, subordinate document (M7-179, “Approved Lubricants, Coolants, and Solvents”) to
facilitate subsequent revisions. All data therein are still considered flow-down requirements from M7-13.
Failure to comply with the requirements contained in the Fabrication Standards may result in the
rejection of the material produced. In the event of a conflict between the standards, the drawing,
and/or the purchase order, the purchase order shall take precedence, the drawing next, and then
the standards.
All questions from Suppliers concerning the interpretation of the standards shall be directed to the CPI
MPP Purchasing Department. Additional information or revisions shall be provided to Suppliers and all CPI
departments engaged in fabrication of piece parts, subassemblies, and finished products.
REFERENCES (Latest Revision)
40 CFR, Part 82
ANSI Y14.5
FED-STD-H28
CPI M7-35
CPI M7-179
CPI P0-1
CPI P0-3
CPI P18-2
Protection of Stratospheric Ozone
Dimensions and Tolerancing
Screw Thread Standards for Federal Services
Inventory Packaging
Approved Lubricants, Coolants, and Solvents
Approved Sources for Raw Materials and Processes (Including Sections 1, 2,
3, and 4)
Supplier Quality System Requirements
Clean Packaging of Supplier-Provided Parts
DEFINITIONS
CMM
EDM
EPA
MMC
Non-Vacuum Assembly
Non-Vacuum Part
OFE
Coordinate Measuring Machine
Electrical Discharge Machining
Environmental Protection Agency
Maximum Material Condition
An assembly that is not within or part of the vacuum envelope
A part that is not within or part of the vacuum envelope
Oxygen Free Electronic
Revision Information
Updated Section 3.0 and Geometric Symbology Appendix
Spec. No.: M7-13
FABRICATION STANDARDS
ECO: MPP615849 Rev. AV
Date: May 16, 2016
MANUFACTURING SPECIFICATION
PO
P-Spec
RFS
Vacuum Assembly
Vacuum Part
VED
1.0
Page 2 of 21
Purchase Order
Purchasing Specification
Regardless of Feature Size
An assembly that is within or part of the vacuum envelope
A part that is within or part of the vacuum envelope
Vacuum Electron Device (modern name for “microwave tube”)
RAW MATERIALS
The performance of VEDs is critically dependent upon the strict conformance of raw materials to
specifications and to proper processing and cleanliness practices. CPI’s products are subjected to
numerous high-temperature cycles during their assembly and processing and must still retain highvacuum integrity, strength, and inherent thermal and magnetic properties. To this end, the Supplier
shall be required to use ONLY the material specified on the drawing or on the PO to fabricate the
required parts.
NOTE
USE OF UNAUTHORIZED MATERIAL IS NOT ALLOWED.
Violations shall result in removal from the Approved Supplier
List and possible exposure to consequential damages.
Some of the raw materials used by CPI have directional properties resulting from segregation or
inclusions that can seriously jeopardize the vacuum integrity of microwave VEDs. For example,

Low-carbon steels have regions of high-carbon content.

Stainless steels contain sulfide or oxide inclusions.

Cupronickel occasionally exhibits slag inclusions.
During ingot reduction, these concentrations of impurities are “stretched out” in the rolling or
drawing direction, forming “stringers” (i.e., in the plane of flat or sheet stock and on the axis for bar
stock). CPI parts that are designed for vacuum applications will always prescribe a material
orientation to ensure that a potential stringer leak path will run parallel to the vacuum wall instead of
piercing it. Allowable forms are defined in the purchasing specification (P-Spec) and denoted in the
materials block of individual drawings by a P-Spec suffix. The “Grain Symbol”
GRAIN
(
) may also be used in instances of critical orientation.

Sourcing of raw materials shall be in strict accordance with CPI P0-1, “Approved Sources for
Raw Materials and Processes.”

All raw materials must be positively identified and directly traceable to the certifications that
demonstrate the material’s conformance to stated requirements.

Surplus material, including remnants, overage, and scrap, that cannot be traced directly to its
certifications shall under no circumstances be used to fabricate parts for CPI.

Alternate forms of raw materials (i.e., plate, bar, sheet, etc.) may not be substituted without
written approval from CPI.

It is unallowable to use welded tubing or to roll and weld flat stock unless specifically
prescribed in the drawing or PO.

It is unallowable to repair parts by welding, plugging, flame spraying, or other methods without
written approval from CPI.
Spec. No.: M7-13
FABRICATION STANDARDS
ECO: MPP615849 Rev. AV
Date: May 16, 2016
MANUFACTURING SPECIFICATION
2.0
Page 3 of 21
STANDARDS FOR RAW-MATERIAL MACHINING ALLOWANCES
This section prescribes machining allowances for raw materials to ensure the removal of surface
defects and oxides. Material with no allowance has been demonstrated to have a useable surface
as received.
2.1
Minimums
The allowances specified are minimums to be removed from each side. Where greater
amounts must be removed, it is recommended that an equal amount be removed from both
sides as permitted by available raw-material dimensions. If surface defects are still visible
after removal of the machining allowance, the material should not be used at all.
2.2
Calculation of Raw-Material Dimensions
The minimum size of the raw material shall be determined as follows:
Determine the “Finished” dimension from the print and ADD the following amounts:
For Chromium Copper/Chromium Zirconium Copper Alloys
(All Forms Except Castings and Forgings)
Under 0.250″ Thick
0.251″ to 1.000″ Thick
Above 1.000″ Thick
0.020″ from each surface
0.030″ from each surface
0.060″ from each surface
For Chromium Copper/Chromium Zirconium Copper Alloys Castings and Forgings
Under 0.250″ Thick
0.251″ to 1.000″ Thick
Above 1.000″ Thick
0.020″ from each surface
0.10″ from each surface
0.50″ from each surface
For OFE Copper (All Forms Except Castings and Forgings)
Under 0.250″ Thick
0.251″ to 1.000″ Thick
Above 1.000″ Thick
None
5% min from each surface
0.062″ from each surface
For OFE Copper Castings and Forgings
Under 0.250″ Thick
0.251″ to 1.000″ Thick
Above 1.000″ Thick
N/A
N/A
0.50″ from each surface
For All Others (Flat Plate and Rectangular Bar)
Under 0.250″ Thick
0.251″ to 1.000″ Thick
Above 1.000″ Thick
None
2% min to each surface
0.020″ min to each surface
Under 0.250″ Dia.
None
For All Others (Round Bar or Rod)
0.251″ Dia. to 1.000″ Dia.
Above 1.000″ Dia.
4% min to diameter
0.040″ min to diameter
Spec. No.: M7-13
FABRICATION STANDARDS
ECO: MPP615849 Rev. AV
Date: May 16, 2016
MANUFACTURING SPECIFICATION
2.3
Page 4 of 21
Tubing
The raw-material sizes for the OD of tubing shall be calculated in the same way as the
round bar diameter.
The maximum ID of tubing shall be calculated by DEDUCTING the following amounts from
the “Finished” dimension:
Under 1.000″ ID
None
3.0
Above 1.000″ ID
0.040″ min
CERTIFICATION
This section defines the items requiring certification as specified by CPI and states the minimum
information that must accompany the parts or assemblies.
3.1
When Certification is Required
Certifications are required for all raw materials, electrical components, and whenever
certifications are indicated by the drawing, PO, or P-Spec.
3.2
Delivery or Storage of Certifications
This section defines the instances wherein the Supplier is to include the certification with the
shipment. In all cases, the Supplier is to maintain certifications as Quality Records at its
facility in accordance with P0-3, “Supplier Quality System Requirements.”
3.2.1
Fabricated Parts, Assemblies, and Processes
Certifications shall be sent with shipments when indicated by any of the following:
A.
Purchase Order
B.
Drawing
C. Purchasing Specification
Any of the following phrases, or a similar phrase with the same intent, may be
used to indicate that certifications must be supplied with shipments:
A.
Certification Required
B.
Certs. Required
C. Certified Reports Shall Be Provided with Shipment
3.2.2
Raw-Material Suppliers and Distributors
All raw-material certifications will be shipped with the material.
3.3
Requirements on All Certifications
The following information must be provided with all certifications:
A.
CPI Purchase Order Number
B.
CPI Part Number/Specification Number and Revision Letter
C. Quantity or Amount in Shipment
Spec. No.: M7-13
FABRICATION STANDARDS
ECO: MPP615849 Rev. AV
Date: May 16, 2016
MANUFACTURING SPECIFICATION
Page 5 of 21
D. Manufacture Lot, Heat, and/or Batch Number
3.4
E.
Compliance Statement
F.
Signature, Title of Company Representative, and Date
Certification Types
The following information must also accompany these specific products or processes:
3.4.1
Age-Dated/Environmentally Controlled Material
A.
Material Description and Type
B.
Storage Conditions
NOTE
Specific storage conditions other than normal ambient and environment
must be stated on the exterior of the package.
C. Expiration Date (must also appear on each container of the product itself)
3.4.2
3.4.3
Ceramics
A.
Material Description
B.
Method of Manufacture (i.e., isostatic, extruded, etc.)
Raw Material (When required by CPI Purchasing Specification)
A.
CPI Material Purchasing Specifications (i.e., P3-1B, P1-7D, etc.)
B.
Size and/or Shape of Material
C. Test Reports (chemical and physical)
3.4.4
3.4.5
Special Processing (Typical processing certifications include plating, priming, heattreating, ceramic metallizing, brazing, welding, etc.)
A.
Total Quantity Processed
B.
Definition of Process (CPI specification, MIL specification, or other brief
description)
Specific Requirements or Tests (Mechanical, Electrical, Environmental)
Description of the specific item being certified
4.0
A.
CPI Drawing and Note Number
B.
Applicable Specification and Requirement
PACKAGING AND LABELING
4.1
Parts Protection in Packing
Parts shall be packaged for shipment so they are protected from damage and
contamination, prevented from nesting and entangling, and easy to unpack. Step 4.1.2B
lists several packaging schemes that can be used as an aid. For more detail on packaging
items, see Section 1 of M7-35, “Inventory packaging.”
Spec. No.: M7-13
FABRICATION STANDARDS
ECO: MPP615849 Rev. AV
Date: May 16, 2016
MANUFACTURING SPECIFICATION
4.1.1
Page 6 of 21
Unacceptable Packing Materials
Dusty and linty materials such as sawdust, shredded newspaper, and excelsior
4.1.2
Suitable Packing Materials
A.
Cellulose wadding (Kimpack), corrugated paper board, and expanded plastics
(specific notes on drawings concerning packing requirements take
precedence.)
B.
Table 1 lists the recommended packaging schemes for several commodities:
TABLE 1. Packaging by Commodity
Commodity
Recommended Packaging
Ceramics
Individually package; bubble wrap
Braze Wafers/Washers
Poly bag; then lay flat in container (see
P18-2 for packaging clean parts)
Bellows
Individually package; divider trays;
Rondo boards
Small Drift Tubes and TWT
Cavity tray VMC-35, purchased from
Anodes
Odyssey
(408) 260-4012
Individually wrap; poly bag
Large Drift Tubes (MPP)
Use plastic end caps to protect the
nose
Diaphragms
Divider trays; individually wrap; poly
bag (one piece per bag)
Individually wrap in bubble wrap, end
CONFLAT® Flanges
cap on knife-edge side
Coupled-Cavity Pole Pieces and
Divider trays P99056, F19951, F19952;
Cavity Plates
poly bag (one piece per bag)
Polished Parts (parts having an
Individually wrap in lint-free paper, then
exposed surface with a 16 finish or place in a bubble bag
better)
4.1.3
Clean Parts Packaging
Refer to CPI specification P18-2, “Clean Packaging of Supplier-Provided Parts,”
for clean parts packaging requirements.
4.1.4
Properly Packed Materials
Pack large shipments and heavy parts in small lots for easier handling. Shipments
packaged in a single corrugated carton shall not exceed 40 pounds.
4.2
Transportation
Corporate Freight Rates
Suppliers are encouraged to take advantage of CPI’s corporate freight rates. Consult
Purchasing for current carrier names and account numbers.
Spec. No.: M7-13
FABRICATION STANDARDS
ECO: MPP615849 Rev. AV
Date: May 16, 2016
MANUFACTURING SPECIFICATION
4.3
Page 7 of 21
Package Labeling
4.3.1
Label Requirements
Label each package as follows:
4.3.2
A.
Name of Supplier
B.
CPI Division Purchase Order Number
C.
Receiving Area
D.
CPI Division Part Number and Revision Letter
E.
Quantity (use same unit of measure as stated on purchase order)
F.
Other applicable information (i.e., Just-in-Time Delivery labels, EPA
requirements, clean parts labels, etc.)
Multiple Container Lots
Lots shipped in more than one container must be sequentially labeled (i.e., Box 1
of 3, Box 2 of 3, etc.)
4.3.3
Consolidated Shipments
A consolidated shipment of multiple items and purchase orders is acceptable,
provided that the shipping container is clearly marked as a consolidated shipment
(see example below). Packing lists for individual purchase orders should be placed
inside the consolidated shipping container.
Sample marking:
CONSOLIDATED SHIPMENT
See packing lists in container for individual purchase orders.
4.3.4
Additional Labeling Requirements
Labels shall meet all Federal and State labeling requirements, including those
established by the EPA in 40 CFR, Part 82, “Protection of Stratospheric Ozone.”
5.0
GEOMETRIC DIMENSIONING AND TOLERANCING SYSTEM
Interpret dimensions and tolerances according to the latest revision of ANSI Y14.5, “Dimensions
and Tolerancing.”
5.1
Unspecified Tolerance
When the tolerance limit is not specified on the drawing or sketch, the following shall apply:
Decimal:
Fraction:
Angles:
1 place ±0.1
2 places ±0.02
3 places ±0.005
4 places ±0.0005
±1/64
±1°
Spec. No.: M7-13
FABRICATION STANDARDS
ECO: MPP615849 Rev. AV
Date: May 16, 2016
MANUFACTURING SPECIFICATION
5.2
Page 8 of 21
Unspecified Finish
The finish requirement for machined surfaces shall be 125
unless otherwise specified.
Flaws are not included in surface finish measurements. The following flaws are not
acceptable unless otherwise specified:

Splits, tears, and cracks

Displaced metal, folds (ironed-in or smeared-over scratches and burrs)

Inclusions (imbedded particles—chips, burrs, foreign matter)

Oxide (rust or corrosion)

Seams
The surface finish must not exceed the average value of microinches shown by the symbol
(
).
Unless otherwise specified, the general finish in the title block applies only to machined
surfaces.
Commercial stock surface finish is acceptable when “stock” is specified as a dimension.
5.3
Unspecified Flatness
When flatness is not specified, it shall not exceed the values in Table 2 and shall not violate
the MMC perfect-form boundary.
TABLE 2: Flatness Tolerance
Surface Finish
Required
63
Unit Variation
in any Direction
0.003 in. per in.
or better
64
or rougher
5.4
0.005 in. per in.
Total Variation
if Length is 1″ or More
0.003 times the longest
element of the feature with a
maximum of 0.012
0.005 times the longest
element of the feature with a
maximum of 0.020
Unspecified Cylindricity
When cylindricity is not specified on the drawing, diameters shall be cylindrical within onehalf the feature size tolerance and shall not violate the MMC perfect-form boundary.
5.5
Unspecified Perpendicularity
When implied right (90) angles are not specified in the drawing, they shall be within ±0 15’
of the intended 90 angle or 0.004 inch per inch maximum error and shall not violate the
MMC perfect-form boundary.
Spec. No.: M7-13
FABRICATION STANDARDS
ECO: MPP615849 Rev. AV
Date: May 16, 2016
MANUFACTURING SPECIFICATION
5.6
Page 9 of 21
Unspecified Parallelism
When surfaces shown in parallel relationship are not specified on the drawing, they shall be
parallel within 0.002 inch per inch of width or length and shall not violate the MMC perfectform boundary.
5.7
Unspecified Concentricity
When concentricity is not specified on the drawing, the concentricity of any two round
features shown on the same centerline shall be equal to one-half the arithmetic sum of the
feature size tolerances. The feature having the smallest total tolerance shall be considered
datum if no datum is specified.
Example: The concentricity between D1 and D2 will be:
Tolerance
D1 = ±0.002 = 0.004 THIS IS DATUM (smallest total tolerance)
D2 = ±0.005 = 0.010
Axis of D2 must be concentric to axis of D1 by 0.007 or less.
[(0.004 + 0.010)/2 = 0.014/2 = 0.007]
FIGURE 1: Unspecified Concentricity
5.8
Unspecified Position
When positional symmetry is not specified, (
formerly
) features shown as lying on
the centerline of a part (i.e., a slot in a screw head) shall be symmetrical within the total
width tolerance of the feature.
5.9
Unspecified Circularity
Diameters that do not have a specified roundness tolerance shall be round within one-half
the feature size tolerance but must not extend beyond the MMC perfect-form boundary.
5.10
Unspecified Countersinks
Unless otherwise specified, all countersinks shall be 82 ±5.
Spec. No.: M7-13
FABRICATION STANDARDS
ECO: MPP615849 Rev. AV
Date: May 16, 2016
MANUFACTURING SPECIFICATION
6.0
Page 10 of 21
TOOLING
Parts contamination can result from contact with some materials commonly used for tooling.
Tooling made of brass, bronze, or platinum shall not be used. Cadmium- or zinc-plated tooling shall
not be used.
Exception: Parts that are not used inside the vacuum envelope of microwave, power-grid, and
X-ray VEDs (or similar devices) are exempt from this requirement. These parts are
either made from brass, aluminum, zinc, lead, and plastic or designated by the
drawing as not used in the vacuum envelope of the VED.
7.0
CLEANING, PLATING, AND COATING OF SURFACES
All fabricated parts must be received at CPI free of machining lubricants, oils, contaminants, and
particles. (The exception to this rule shall be components made from materials that would rust if not
protected by an approved rust inhibitor. Materials in this category shall be degreased and coated
with an approved rust inhibitor before being packaged for shipment or introduced into the Supplier's
stock).
Plating, coating, or other metal finishing to be performed by Suppliers shall be specified on the
drawing using military or industry standards. All quality-assurance provisions in the standard shall
apply. Processes to be performed within CPI shall refer to the CPI specification.
When a part or assembly drawing specifies plating or coating, dimensions on the drawing are the
machined/fabricated dimensions. The part or assembly has been designed to allow for the
application of the plating or coating as specified. Any dimensions that apply after plating will be
noted separately.
Specified coating thicknesses are the average thickness for the entire part. Normal thickness
distribution based on current density is assumed. For example, areas of high-current density, such
as sharp edges and outer ends of parts, can have considerably more than the specified coating
thickness. Areas of critical thickness will be noted on the drawing. Compliance to critical thickness
specifications must be verified and documented.
All threaded holes shall be masked prior to plating or painting to ensure there is no buildup of the
plating or paint in the threaded hole.
8.0
BURRS
Burrs adversely affect VED performance by acting as traps for chemical cleaning solutions, serving
as “virtual” leaks and as point emission sources in areas of high-electrical potential.
8.1
Definition
A burr is found at the edge of a stamped or machined feature and is defined as a small
projection of material that interrupts the normal contour of the plane or surface. (Note that
this definition says a burr can only occur at an edge of a feature; anything on the surface is
a nodule or particle, etc.)
Spec. No.: M7-13
FABRICATION STANDARDS
ECO: MPP615849 Rev. AV
Date: May 16, 2016
MANUFACTURING SPECIFICATION
8.2
Page 11 of 21
Types
Various types of burrs are defined as follows:

An imbedded burr is any burr that has been pressed into the material.

A feather burr is a very fine or thin burr generally less than 0.001-inch thick.

A hanging burr is a burr that is not firmly attached to the workpiece.

A rolled-over burr is a tight burr that is curled over on itself in such a manner that it
traps contaminants within itself.
NOTE:
8.3
ROLLED-OVER AND IMBEDDED BURRS ARE NOT ALLOWED. EMBEDDED
PARTICLES ARE NOT ALLOWED.
Height
Hanging burrs and feather burrs are subject to the limits prescribed below.
Burr height is defined as the maximum distance the burr projects above the surface of the
workpiece.
TABLE 3. Burr Heights
Maximum Burr Heights Allowed for Machined Features
32
Finish or Better
0.0005
63
Finish
0.002
125
Finish or Worse
0.003
In addition to burr height, burr direction may be a critical factor for sheet-metal parts. If so,
the burr direction will be called out on the drawing (see Section 10.12).
Maximum burr heights for sheet-metal parts will be found in Section 10.11.
8.4
Removal
It shall be standard practice to remove burrs from the edges of all surfaces, even if this
requirement is not noted on the drawing, such that the requirements stated in Section 8.2
and Section 8.3 are satisfied.
The notation “No Burrs” appearing on a drawing specifies that burrs be removed to the
extent that they are not visible under 10X magnification.
While deburring, it is imperative that excessive material is not removed; after deburring, the
parts must still be within the dimensional tolerances specified on the print.
The deburring method used must not introduce any contamination, and all loose particles
must be removed.
Contamination resulting from embedded particles introduced during the deburring
processes can adversely affect the performance of our product. The use of bonded
abrasives (i.e., a Cratex stick) that can leave embedded particles is NOT acceptable.
Spec. No.: M7-13
FABRICATION STANDARDS
ECO: MPP615849 Rev. AV
Date: May 16, 2016
MANUFACTURING SPECIFICATION
8.5
Page 12 of 21
Edges
An edge is defined as the intersection of two planes of base material at an angle greater
than 180 (outside).
180¡
180
EDGE
D4019
FIGURE 2: Edges
It shall be standard practice to remove all sharp edges unless otherwise specified.
Edges shall be broken by either a 45 chamfer or a radius. If limits are not specified on the
drawing, a 0.005-inch maximum chamfer or radius is acceptable for lengths less than
1 inch. For features greater than 1 inch, a 0.010-inch maximum chamfer or radius is
acceptable.
A “sharp edge” callout on a drawing shall be interpreted as being limited to a 0.002-inch
maximum chamfer or radius.
8.6
Corners
A corner shall be defined as the intersection of two or more planes of base material at an
angle less than 180 (inside).
CORNER
180¡
D4020
FIGURE 3: Corners
Unless otherwise specified on the drawing, all corners shall be limited to a 0.010-inch
maximum radius.
A “sharp corner” callout on a drawing shall be interpreted as being a corner with no greater
than a 0.002-inch maximum radius.
Undercuts shall be subject to rejection unless otherwise specified on the drawing.
Spec. No.: M7-13
FABRICATION STANDARDS
ECO: MPP615849 Rev. AV
Date: May 16, 2016
MANUFACTURING SPECIFICATION
8.7
Page 13 of 21
Sheet Metal
For additional requirements concerning burrs on sheet-metal products, see Section 10.11.
9.0
THREADS
All threads, unless otherwise specified on the drawing, shall conform to the unified tabulations and
formulations of FED-STD-H28, “Screw Thread Standards for Federal Services.” Unified form
threads, American National Form threads, special threads, and unified miniature screw threads
shall be defined by the unified system.
9.1
Internal Threads
All internal threads shall be tapped using standard machine screw taps or machined.
THREAD-FORMING TOOLS ARE PROHIBITED UNLESS OTHERWISE SPECIFIED as
formed threads can trap contaminants. EXCEPTION: Parts that are not used inside the
vacuum envelope of vacuum-electron devices are exempt from this requirement. These
parts are either made from brass, aluminum, zinc, lead, or plastic or are designated by the
drawing as not used in the vacuum envelope of the VED.
9.2
Threaded Holes
All threaded holes shall be countersunk 82 ± 5 to a diameter equal to at least the major
diameter of the specified thread. In the case of through-holes, this requirement shall apply
to both ends. The countersink diameter shall not exceed 0.020 inch over the major thread
diameter.
The specified depth of a threaded hole shall mean there shall be full threads to that depth.
Where a three-place decimal dimension (± 0.005 tolerance) is used to define thread depth,
one full thread shall be allowed beyond the dimension.
The depth of the tap drill shall not be specified unless critical. If the depth of a tap/twist drill
hole is not specified, the depth of the hole shall not exceed the full thread depth plus a dimensional allowance equal to the nominal thread diameter.
FULL THREAD
DEPTH
MAX. DEPTH OF HOLE=
FULL THREAD DEPTH
PLUS THREAD DIA.
FIGURE 4: Thread Depth
In gauging a threaded hole, the “No-Go” gauge shall not penetrate more than three turns.
Exceptionally short thread length (less than three pitches) may pass over the plug gauge
provided there is a perceptible drag. The “Go” gauge shall freely penetrate the full length of
the thread.
Spec. No.: M7-13
FABRICATION STANDARDS
ECO: MPP615849 Rev. AV
Date: May 16, 2016
MANUFACTURING SPECIFICATION
9.3
Page 14 of 21
Threaded Parts
The end of all external threads shall be chamfered at 45 ± 5 to the minor diameter.
9.4
Full-Form Threads
The length of fully formed threads is dimensioned. When only one dimension is used to
specify the length of threads, it is interpreted to mean the length of fully formed threads,
excluding runout. Where a chamfer, not exceeding two pitches in length, exists at the
entering end of the thread, it is included in the length of fully formed threads. Figure 5 below
shows methods of delineating with no limit on runout.
X.XXX
X.XXX
THREAD LENGTH
D4025
FIGURE 5: Thread Length
9.5
Unspecified Thread Class of Fit
TABLE 4: Thread Class
Thread Description
External Threads
Internal Threads
External Threads (Metric)
Internal Threads (Metric)
Threaded Inserts (#3–#8)
Threaded Inserts (>#8)
10.0
Thread Class of Fit
2A
2B
6G
6H
2B
2B or 3B
SHEET-METAL PRODUCTS FABRICATION REQUIREMENTS
10.1
Sheet Metal
Sheet metal is considered to be sheet stock that has a nominal thickness of 0.250 (1/4) inch
or less.
10.2
Features and Surfaces
Features and surfaces of sheet-metal parts shall be within drawing dimensional limits of size
in the unrestrained condition unless otherwise specified.
Spec. No.: M7-13
FABRICATION STANDARDS
ECO: MPP615849 Rev. AV
Date: May 16, 2016
MANUFACTURING SPECIFICATION
10.3
Page 15 of 21
Machined Features
Obvious machined features such as countersinks, chamfers, screw threads, and closetolerance (0.003 inch or less) holes shall conform to the body of this standard.
10.4
Circular Runout
The circular runout of any internal or external diameter shall not exceed the value specified
in Table 5 with respect to any other diameter on the same axis. If a datum axis is
established by the drawing, the circular runout shall be in relation to that datum axis.
TABLE 5: Circular Runout of Diameters
DIAMETER
(Inches)
Through 6.000
6.001 through 9.000
9.001 through 20.000
20.001 through 36.000
Over 36.000
10.5
CIRCULAR RUNOUT TOLERANCE
(Inches)
0.040
0.070
0.100
0.150
0.200
Washer-Type Punching
The center hole of washer-type punchings shall be located within the position tolerance
shown in Table 6 in relation to the outside diameter.
TABLE 6: True Position of Washer-Type Punchings Relative to
OD as Datum Feature
INSIDE DIAMETER
(Inches)
Through 6.000
6.001 through 12.000
12.001 through 24.000
Over 24.000
10.6
POSITION TOLERANCE (MMC)
(Inches)
0.030 dia.
0.060 dia.
0.100 dia.
0.150 dia.
Flatness
Variations in surface flatness shall not exceed the values shown in Table 7 and Table 8 and
shall not violate the dimensional limits of size.
TABLE 7: Flatness for Nonwelded Surfaces
NOMINAL STOCK THICKNESS
(Inches)
Through 0.090
0.091 through 0.250
UNIT VARIATION IN ANY
DIRECTION
0.010 in/in
0.007 in/in
Spec. No.: M7-13
FABRICATION STANDARDS
ECO: MPP615849 Rev. AV
Date: May 16, 2016
MANUFACTURING SPECIFICATION
Page 16 of 21
TABLE 8: Flatness for Welded/Brazed Surfaces
NOMINAL STOCK THICKNESS
(Inches)
Through 0.032
0.033 through 0.060
0.061 through 0.125
0.126 through 0.250
10.7
UNIT VARIATION IN ANY
DIRECTION
0.025 in/in
0.020 in/in
0.015 in/in
0.005 in/in
Parallelism and Perpendicularity
The elements of flat sheet-metal surfaces that are shown as parallel or perpendicular shall
be parallel or perpendicular to each other within 3. The datum shall be the longest adjacent
surface that is parallel or perpendicular to the surface being measured.
10.8
Edges and Corners
Sheared edges are permissible but they, and all other edges and corners, shall be broken in
accordance with the illustration below. This applies only to finished parts and not to “inprocess” pieces of a welded or brazed assembly.
0.015
0.005
RAD.
EXTERNAL EDGES
AND CORNERS
SHALL FALL ENTIRELY
WITHIN THE CROSSHATCHED AREA. NO
BURRS PERMITTED.
0.015
FIGURE 6: Edges and Corners
10.9
Stock Thickness after Forming
Sheet-metal thickness in areas affected by forming may be reduced by a maximum of
25 percent of the maximum stock thickness. Local thickening due to the part shape and the
forming process is acceptable up to 30 percent of the maximum stock thickness.
If material thickness is 0.025” or less, supplier must verify thickness and pay particular
attention to the formed feature(s). Verification methods can include mechanical
measurement, CMM, cross-section (i.e., EDM cut, metallurgical section, milling), or
ultrasonic.
Spec. No.: M7-13
FABRICATION STANDARDS
ECO: MPP615849 Rev. AV
Date: May 16, 2016
MANUFACTURING SPECIFICATION
Page 17 of 21
10.10 Breakaway
The maximum breakaway of punched or sheared edges shall not be more than 20 percent
of the stock thickness as shown below. The dimensional limits of size apply only to those
portions of the edge where breakaway has not occurred.
FIGURE 7: Maximum Breakaway
10.11 Burrs
The following burr specifications are in addition to those covered in Section 8:
Limitations — under the conditions specified below, maximum burr heights are as follows
(also see illustration in Section 10.12):
TABLE 9: Burr Height Allowance
STOCK THICKNESS
0.004 and under
over 0.004 to 0.014 incl.
over 0.014 to 0.039 incl.
over 0.039 to 0.124 incl.
over 0.124 to 0.186 incl.
over 0.186 to 0.311 incl.
over 0.311
MAX BURR HEIGHT ALLOWANCE
0.001
0.0015
0.002
0.003
0.004
0.005
0.010
Wire and ribbon burrs on cut lengths of wire and ribbon, including flattening because of
shearing pressure, shall not exceed 10 percent of the diameter or thickness unless
otherwise specified.
Spec. No.: M7-13
FABRICATION STANDARDS
ECO: MPP615849 Rev. AV
Date: May 16, 2016
MANUFACTURING SPECIFICATION
Page 18 of 21
10.12 Burr Symbols and Drawing Callouts

A “B” symbol placed on extension lines indicates that burrs are acceptable.

The maximum burr height allowed is shown adjacent to the symbol.

Arrowheads may be used to indicate the side on which burrs may occur.

Symbols placed on both sides indicate that burrs are acceptable on both sides.

A radius may be specified on an edge to show the direction of punching.
FIGURE 8: Burr Symbols
11.0
CASTING AND FORGING REQUIREMENTS
11.1
Position
The position of coaxial or coplanar cast or forged features shall be in accordance with Table
10 with respect to each other; it should be noted that the position does not include out-ofroundness. If a cast or forged datum axis is established by the drawing, the position control
shall be in relation to that datum axis. The concentricity shall be ±0.010″ at the lowest point
on the surface of the forging before any surface-removal procedure (OFE Copper only).
TABLE 10: Position of Coaxial/Coplanar Features
Sand Casting
Die Castings
Shell, Plaster, Ceramic,
Permanent Mold, or
Investment Castings
Forgings
Feature Dia/Width
Position Tol. RFS (S)
Up to 6.000
6.001 to 12.000
Over 12.000
Up to 6.000
6.001 to 12.000
Over 12.000
Up to 6.000
6.001 to 12.000
Over 12.000
Up to 6.000
6.001 to 12.000
Over 12.000
0.060
0.090
0.120
0.020
0.040
0.060
0.040
0.060
0.080
0.060
0.090
0.120
Spec. No.: M7-13
FABRICATION STANDARDS
ECO: MPP615849 Rev. AV
Date: May 16, 2016
MANUFACTURING SPECIFICATION
11.2
Page 19 of 21
Flatness
Surface flatness shall not exceed the values specified in Table 11 except in the area of a
parting line.
TABLE 11: Flatness
FLATNESS TOLERANCE
Variation In
Total Variation
Any Direction
(Lengths of More Than 1 Inch)
Surface Finish
250 and Finer
0.015 in./in.
0.060 max
251 Through 500
0.020 in./in.
0.080 max
500 and Finer
0.010 in./in.
0.060 max
500 and Over
0.020 in./in.
0.100 max
Castings
Forgings
11.3
Cleanup
Gates, risers, flash, runners, and parting lines on surfaces not subject to subsequent
machining shall be trimmed and blended smooth with the part contour. Surfaces subject to
subsequent machining shall be finished according to normal industry practice.
11.4
Mismatch
Parting-line mismatch for forgings shall not exceed 0.05 inch maximum. Mismatch is
defined as a defect resulting from die misalignment, producing an offset on the surfaces of
the forging at the parting line. The mismatch of castings shall be contained within the
applicable position requirements.
11.5
Draft
Draft shall be applied as additional material to the dimensions shown on the drawing and
shall not exceed the limits specified in Table 12.
TABLE 12: Draft Angle
DRAFT ANGLE
Internal
External
Sand, Shell Mold, and Ceramic Mold Castings
Plaster Mold Castings
Investment Castings
Permanent Mold and Semiperm Mold Castings
Forgings
3 max
3 max
130’ max
4 max
10 max
3 max
130’ max
130’ max
4 max
8 max
Spec. No.: M7-13
FABRICATION STANDARDS
ECO: MPP615849 Rev. AV
Date: May 16, 2016
MANUFACTURING SPECIFICATION
11.6
Page 20 of 21
Repair
Castings and forgings shall not be repaired by welding, plugging, impregnating, peening, or
any other methods except as permitted by specific drawing notes. Castings that shall be
subsequently welded or brazed shall not be impregnated. Surface conditioning using
standard shop practice for removal of surface defects is permissible within drawing
dimensional limits.
12.0
EDM FABRICATION REQUIREMENTS
For components fabricated using an EDM process (including wire EDM), parts will be delivered free
of any contaminants from the dielectric fluid and electrode material. If transfer of material from the
electrode is unavoidable, the supplier is responsible for subsequent cleaning to remove the deposit
or for using a non-contaminating electrode such as tungsten.
Spec. No.: M7-13
FABRICATION STANDARDS
ECO: MPP615849 Rev. AV
Date: May 16, 2016
MANUFACTURING SPECIFICATION
Page 21 of 21
APPENDIX: GEOMETRIC SYMBOLOGY
SYMBOL
MEANS
Datum Symbol
Datum Target
()
ANSI REFERENCE
3.3.2
3.3.3
Basic Dimension
3.3.4
Diameter
3.3.7
Spherical Diameter
Reference
Feature Control Frame
--3.3.8
3.4.2.1
Least Material Condition (LMC)
Regardless of Feature Size (RFS)
Maximum Material Condition (MMC)
3.3.5
3.3.5
3.3.5
Projected Tolerance Zone
3.3.6
Radius
Spherical Radius
Arc Length
Chain Line
Flatness
Flatness on Older Prints
Straightness
Circularity (Roundness)
3.3.7
1.8.2.5
3.3.9
--6.4.2
--6.4.1
6.4.3
Cylindricity
Perpendicularity
6.4.4
6.6.4
Angularity
6.6.2
Parallelism
Profile of a Line
Profile of a Surface
Circular Runout
Total Runout
Concentricity/Coaxiality
Position
6.6.3
6.5.2 (b)
6.5.2 (a)
6.7.2.1
6.7.2.2
5.11.3
5.2
Symmetry (Use of Preferred Position)
Counterbore or Spotface
Countersink
Depth
--3.3.10
3.3.11
3.3.12
Repetitive Features and Dimensions
---