1、 FORD LABORATORY TEST METHOD BV 012-01 Date Action Revisions 2000 12 01 Revised Editorial no technical change A. Cockman 1992 08 12 Printed copies are uncontrolled Page 1 of 3 Copyright 2000, Ford Global Technologies, Inc. TEST FOR LOCKING STRENGTH OF SEALERS Application This procedure is used to te
2、st the locking strength of anaerobic type sealing compounds used for sealing and retaining metal parts such as threaded fasteners or plugs. Scope This procedure describes a series of tests, each of which depends upon a certain set of conditions, although sample preparation is similar for each set. (
3、a) Locking strength after normal curing. (b) Locking strength after immersion in ESE-M97B18-C, Long Life Coolant. (c) Locking strength after heating (hot strength). (d) Locking strength after heat aging. Apparatus and Equipment Required Torque Wrenches Calibrated in inch pounds and suitable for the
4、test range of this material. Oven Mechanical convection - capable of maintaining preset temperatures to +/-5 F between 190 and 400 F. Reflux Condenser and Flask with Electric Heater Desiccator For dry storage of test specimens. Conditioning and Test Conditions All test values indicated herein are ba
5、sed on material conditioned in a controlled atmosphere of 23 +/- 2 C and 50 +/- 5 % relative humidity for not less than 24 h prior to testing and tested under the same conditions unless otherwise specified. FORD LABORATORY TEST METHOD BV 012-01 Page 2 of 3 Copyright 2000, Ford Global Technologies, I
6、nc. Procedure Preparation of Test Specimens The threaded fasteners used in these tests shall be steel bolts and nuts 3/8 inch size, coarse or fine threads as indicated. They shall meet the specifications for unified thread series Class 2 fit as designated by the Ford Standards Parts Book. The bolts
7、and nuts may be the unified coarse thread series, Ford Class 2 fit (3/8 - 16 UNC2) or the unified fine thread series, Class 2 fit (3/8 - 24 UNF2). They shall have a type S finish (plain). The bolts shall have a nominal length of 1 inch with a hexagonal or square head and finished. The nuts shall be
8、regular thickness (nominal 21/64 inch) and finished. Nuts and bolts shall be vapor degreased and 100 % inspected. Reject any pieces with evidence of thread damage. Nuts shall be screwed onto the bolts and moved back and forth with the fingers, care being taken to avoid fingerprints which may result
9、in corrosion of the bolts. Bolt - nut pairs showing excessively tight or loose or sticking due to burrs shall be rejected. However, no effort shall be made to select pairs having matched clearances and the threads shall not be cleaned with a file tap or die. Nuts shall be screwed onto the bolts unti
10、l approximately 5/8 inch of the threaded end of the bolt protrudes and the assemblies then stored in a desiccator until used for the test required. Application of Sealer The intent of this method is to provide a test specimen which shall have the volumetric clearance between the nut and the bolt com
11、pletely filled with the sealant. There should be no entrapped air bubbles in the joint since this condition will produce artificially low locking torque measurements. To start a test, sufficient compound shall be applied by means of the applicator nozzle supplied with the product to cover completely
12、 the protruding threads of the bolt. The nut shall then be unscrewed over the compound until the end of the nut is flush with the end of the bolt. Apply enough sealant to completely fill at least the first 6 threads adjacent to the bolt head side of the nut and slowly advance the nut towards the bol
13、t head approximately 6 to 8 threads. Store the assembled fasteners in the vertical position with the nut up. Visually examine fasteners for presence of fillet on top side of joint. If no fillet is evident, apply 2 or 3 drops of sealant to joint. Measurement of Locking Strength Grip the head of the b
14、olt in a vise and turn the nut away from the bolt head by means of a calibrated torque wrench, turning at a steady constant rate. Take the torque readings at the end of the 1/4 turn increments to one turn. Read at 90, 180, 270 and 360 degrees of rotation while continuing to rotate the nut slowly wit
15、h a torque wrench. Average the first 4 readings to determine the locking torque. The torque of the second turn shall not exceed any reading of the first turn. This test measures the dynamic or moving torque necessary to continue rotation of the nut once the adhesive bond has been broken. The torque
16、required is a measure of the force required to grind up or crush the solid particles of cured resin between the mating thread flanks. FORD LABORATORY TEST METHOD BV 012-01 Page 3 of 3 Copyright 2000, Ford Global Technologies, Inc. Test (a) - Locking Strength After Normal Curing 1. Prepare 4 test ass
17、emblies with compound. 2. Room temperature cure (polymerize) for 48 h at 72 +/- 5 F and 40 - 70 % relative humidity or as specified. 3. Measure locking strength at room temperature as described above. Report the average of 4 specimens as the measurement of locking strength. Test (b) - Locking Streng
18、th After Immersion 1. Prepare 4 test assemblies with compound. 2. Room temperature cure (polymerize) for 48 h at 72 +/- 5 F and 40 - 70 % relative humidity or as specified. 3. Place specimens in a flask, cover with ESE-M97B18-C Long Life Coolant, mixed 50/50 with water, attach reflux condenser to th
19、e flask and heat for 168 h at 190 +/- 5 F. 4. Immediately on removal of the test specimens, check torque as described above. Report the average of 4 specimens as the measurement of locking strength. Test (c) - Locking Strength After Heating (Hot Strength) 1. Prepare 4 test samples with compound. 2.
20、Room temperature cure (polymerize) for 48 h at 72 +/- 5 F and 40 - 70 % relative humidity, or as specified. 3. Heat for 2 h at 190 +/- 5 F in a mechanical convection oven. 4. Within 30 s after removal from the oven, check torque as described above. Report the average of 4 specimens as the measuremen
21、t locking strength. Test (d) - Locking Strength After Heat Aging 1. Prepare 4 test samples with compound. 2. Room temperature cure (polymerize) for 48 h at 72 +/- 5 F and 40 - 70 % relative humidity, or as specified. 3. Heat in a mechanical convection oven at 350 +/- 5 F for 120 h. 4. Cool to 72 +/-
22、 5 F and check torque as described in applicable paragraph. Report the average of 4 specimens as the measurement of locking strength. Chemicals, materials, parts, and equipment referenced in this document must be used and handled properly. Each party is responsible for determining proper use and handling in its facilities.
