1、 FORD LABORATORY TEST METHOD BV 128-01 Date Action Revisions 2000 12 11 Revised Editorial no technical change A. Cockman 1990 09 26 Printed copies are uncontrolled Page 1 of 3 Copyright 2000, Ford Global Technologies, Inc. BREAKAWAY AND PREVAILING TORQUE OF PRE-APPLIED SEALERS ON EXTERNALLY THREADED
2、 FASTENERS Application This method evaluates pre-applied thread locking sealants for breakaway and prevailing torque. Apparatus Required TeflonR Coating Block M 15 Short Box Wrench M 15 Socket Fixture Dial Torque Wrench with Maximum Pointer (0-35 N-m preferred) Lab Oil 72D Solution (5 % in water) in
3、 a pump spray container. Blue M Model OV-560A-2 or equivalent Drying Oven. 100 mL Polyethylene Beaker Wooden Tongue Depressors Metal Plate (round or rectangular) Thermal Mitt Test Specimen M 10 x 1.5, with property class 9.8 or 10.9 degreased, phosphate coated bolts. (All from one lot.) M 10 x 1.5,
4、with property class 9 or 10 “as received“ - phosphate and oil coated free running nuts. (All from one lot.) Conditioning and Test Conditions All test values indicated herein are based on material conditioned in a controlled atmosphere of 23 +/- 2 C and 50 +/- 5 % relative humidity for not less than
5、24 h prior to testing and tested under the same conditions unless otherwise specified. FORD LABORATORY TEST METHOD BV 128-01 Page 2 of 3 Copyright 2000, Ford Global Technologies, Inc. Procedure Sealer Application 1. Apply the threadlocking sealer to half the surface length of the TeflonR coating blo
6、ck. 2. Using a rolling and draw action, roll the bolt in the sealer until all threads are coated. Then roll and draw the bolt over the clean portion of the block surface to wipe any excess sealer off. 3. The bolts should then be placed on the metal plate with uniform spacing (thread side up). 4. Aft
7、er the required amount of bolts are coated, spray the bolts on the plate with a mist of the Lab Oil solution. The mist may be applied in any fashion to insure a consistent coverage of the coated bolts. 5. Insert the plate of bolts into the oven (preheated to 75 C +/- 2 C) and dry for 60 - 65 minutes
8、. When the drying time is complete, remove the bolts and allow them to cool for at least 8 h at 23 +/- 2 C. Test Specimen Assembly 1. Attach the M 15 socket fixture to the side of the lab bench. 2. Obtain a free running nut and examine the nut; there are 2 distinct sides. On 1 side there is an inden
9、tation before the thread begins. This side of the nut shall be the one the bolt is threaded through. All assemblies must have the bolt threaded through the indented side of the nut; otherwise, peeling will occur producing invalid test results. 3. Take 1 bolt and assemble a nut 1 full turn in by hand
10、. Put the partially assembled nut and bolt into the socket fixture “nut side in“. 4. Using the “box end“ of the M 15 short wrench, slowly turn the bolt until 1 full adhesive coated thread protrudes through the nut. 5. The nut and bolt assemblies should be randomly separated into pairs for each test
11、to be performed. 6. For all tests, the assembly is to be inserted “nut first“ into the socket fixture. The bolt will be turned for the required measurements. Torque Measurement 1. All assemblies should be broken in a counterclockwise (off) direction using the dial torque wrench. 2. Breakaway torque
12、is the torque reading, in the off direction, which first breaks the hardened adhesive between the threads of the assembly. 3. The torque wrench is turned 1/8 revolution from the break torque and the prevailing off torque is then measured as the highest torque reading during the next 360 counterclock
13、wise rotation. FORD LABORATORY TEST METHOD BV 128-01 Page 3 of 3 Copyright 2000, Ford Global Technologies, Inc. Condition A - Room Temperature Cure Strength 1. 10 assemblies are allowed to cure for 72 h at 23 +/- 2 C in an upright position (threads up). 2. After 72 h, the breakaway and prevailing of
14、f-torque values are measured and recorded. Condition B - High Temperature Cure Strength 1. 10 assemblies are allowed to cure for 72 h at 23 +/- 2 C in an upright position (threads up). 2. After 72 h, the assemblies are placed in a drying oven at 150 +/- 2 C for 1 h. 3. The assemblies shall be remove
15、d, individually, from the oven and the breakaway and prevailing off-torque values measured and recorded. The assemblies shall not be allowed to cool significantly. Condition C - High Temperature Cyclic Cure Strength 1. 10 assemblies are allowed to cure for 72 h at 23 +/- 2 C in an upright position (
16、threads up). 2. After 72 h, the assemblies are placed in the drying oven (preheated to 149 +/- 2 C). 3. After 1 h at temperature, the assemblies are removed from the oven and allowed to cool to 23 +/- 2 C. 4. The breakaway and prevailing off-torque values are then measured and recorded. 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.
