Technical Data Sheet Product 638 Worldwide Version, October 1995 PRODUCT DESCRIPTION LOCTITE® Product 638 is a single component anaerobic retaining adhesive which develops high strength rapidly when confined in the absence of air between close fitting metal surfaces. Cure speed vs. temperature The rate of cure will depend on the ambient temperature. The graph below shows shear strength developed with time on steel pins and collars at different temperatures and tested according to ISO 10123. PROPERTIES OF UNCURED MATERIAL Range 2,500 1,800 to 3,300 2,250 >93 1,500 to 3,000 TYPICAL CURING PERFORMANCE Cure speed vs. substrate The rate of cure will depend on substrate used. The graph below shows shear strength developed with time on steel pins and collars compared to different materials and tested according to ISO 10123. % of Full Strength on steel 100 75 Zinc Dichromate 50 Steel 40°C 75 22°C 5 °C 50 25 0 5min 10min 30min 1hr 3hr 6hr 24hr Cure speed vs. activator Where cure speed is unacceptably long, or large gaps are present, applying activator to the surface will improve cure speed. The graph below shows shear strength developed with time using ACTIVATOR N and T on zinc dichromated steel pins and collars and tested according to ISO 10123. 100 75 No Activator 50 Act T Act N 25 0 5min 10min Aluminium 30min 1hr 3hr 6hr 24hr 72hr Cure Time, Hours 25 TYPICAL PROPERTIES OF CURED MATERIAL 0 5min10min 30min 1hr 3hr 6hr 24hr 72hr Cure Time, Hours Physical Properties Coefficient of thermal expansion, ASTM D696, K-1 Coefficient of thermal conductivity, ASTM C177, W.m-1K- 80 x 10-6 0.1 Specific Heat , kJ.kg-1K-1 0.3 1 Cure speed vs. bond gap The rate of cure will depend on the bondline gap. The following graph shows shear strength developed with time on steel pins and collars at different controlled gaps and tested according to ISO 10123. % of Full Strength on steel 72hr Cure Time, Hours % of Full Strength on steel Chemical Type Appearance Specific Gravity @ 25°C Viscosity @ 25°C, mPa.s (cP) Brookfield RVT Spindle 3 @ 20 rpm DIN 54453, MV D = 129 s-1 after t=180secs Flash Point (TCC), °C Typical Value Urethane methacrylate Green, fluorescent liquid 1.09 % of Full Strength on steel 100 TYPICAL APPLICATIONS Used to bond cylindrical fitting parts, particularly where bond gaps can approach 0.25mm (0.01") and where maximum strength at room temperature is required. Applications include locking bushings and sleeves into housings and on shafts. PERFORMANCE OF CURED MATERIAL (After 24 hr at 22°C on steel) 100 Typical Shear Strength, ISO 10123, N/mm² (psi) Shear Strength, DIN 54452, N/mm² (psi) 75 0.15mm 50 Value 31 (4500) 27.5 (4000) Range 22 to 40 (3200 to 5900) 20 to 35 (2900 to 5000) 0.05mm 25 0.25mm 0 5min10min 30min 1hr 3hr 6hr 24hr 72hr Cure Time, Hours NOT FOR PRODUCT SPECIFICATIONS THE TECHNICAL DATA CONTAINED HEREIN ARE INTENDED AS REFERENCE ONLY. PLEASE CONTACT LOCTITE CORPORATION QUALITY DEPARTMENT FOR ASSISTANCE AND RECOMMENDATIONS ON SPECIFICATIONS FOR THIS PRODUCT. ROCKY HILL, CT FAX: +1 (860)-571-5473 DUBLIN, IRELAND FAX: +353-(1)-451 - 9959 TDS 638 October 1995 TYPICAL ENVIRONMENTAL RESISTANCE Test Procedure : Shear Strength, ISO 10123 Substrate: Steel Pins and Collars Cure procedure: 1 week at 22°C Directions for use For best performance surfaces should be clean and free of grease. Ensure joint is completely filled with adhesive. For slip fitted assemblies this is achieved by applying adhesive around the pin and the leading edge of the collar and using a rotating motion during assembly to ensure good coverage. For press fitted assemblies adhesive should be applied thoroughly to both bond surfaces and assembled at high press on rates. For shrink fitted assemblies the adhesive should be coated onto the pin, the collar should then be heated to create sufficient clearance for free assembly. Parts should not be disturbed until sufficient handling strength is achieved.. For more detailed information on using retaining adhesives contact your local Technical Service Centre. Hot Strength Tested at temperature. % RT Strength 100 75 50 25 0 0 100 50 150 Temperature, °C % Initial Strength, at RT Heat Ageing Aged at temperature indicated and tested at 22°C. 125 Data Ranges The data contained herein may be reported as a typical value and/or range (based on the mean value ±2 standard deviations). Values are based on actual test data and are verified on a periodic basis. 120°C 100 150°C 75 50 25 0 0 1,000 2,000 Hours 3,000 4,000 5,000 Chemical / Solvent Resistance Aged under conditions indicated and tested at 22°C. Solvent Temp. Motor Oil Unleaded Petrol Brake Fluid Water/Glycol (50%/50%) Ethanol Acetone 125°C 22°C 22°C 87°C 22°C 22°C % Initial Strength retained at 100 hr 500 hr 1000 hr 100 100 100 95 100 90 100 90 90 80 100 90 Storage Product shall be ideally stored in a cool, dry location in unopened containers at a temperature between 8°C to 28°C (46°F to 82°F) unless otherwise labelled. Optimal storage is at the lower half of this temperature range. To prevent contamination of unused product, do not return any material to its original container. For further specific shelf life information, contact your local Technical Service Centre. 100 85 80 80 75 90 GENERAL INFORMATION This product is not recommended for use in pure oxygen and/or oxygen rich systems and should not be selected as a sealant for chlorine or other strong oxidising materials. Note The data contained herein are furnished for information only and are believed to be reliable. We cannot assume responsibility for the results obtained by others over whose methods we have no control. It is the user's responsibility to determine suitability for the user's purpose of any production methods mentioned herein and to adopt such precautions as may be advisable for the protection of property and of persons against any hazards that may be involved in the handling and use thereof. In light of the foregoing, Loctite Corporation specifically disclaims all warranties expressed or implied, including warranties of merchantability or fitness for a particular purpose, arising from sale or use of Loctite Corporation’s products. Loctite Corporation specifically disclaims any liability for consequential or incidental damages of any kind, including lost profits. The discussion herein of various processes or compositions is not to be interpreted as representation that they are free from domination of patents owned by others or as a licence under any Loctite Corporation patents that may cover such processes or compositions. We recommend that each prospective user test his proposed application before repetitive use, using this data as a guide. This product may be covered by one or more United States or foreign patents or patent applications. For safe handling information on this product, consult the Material Safety Data Sheet, (MSDS). Where aqueous washing systems are used to clean the surfaces before bonding, it is important to check for compatibility of the washing solution with the adhesive. In some cases these aqueous washes can affect the cure and performance of the adhesive. This product is not normally recommended for use on plastics (particularly thermoplastic materials where stress cracking of the plastic could result). Users are recommended to confirm compatibility of the product with such substrates. Loctite is a Registered Trademark of Loctite Corporation, Hartford, CT 06106