Re-Install Reliability

In this installment of Diamond Claw® Notes, we discuss testing done to verify Re-install Reliability for Diamond Claw® Friction Shims. 

All tests for this comparison used a set of hardened 50-HRC 4140 samples with a 32µin maximum surface roughness.  The grinder lay was perpendicular to the applied tensile load and the applied compressive load for all tests was set to 6000-lb.

Test-A: The initial test was loaded and run to 80% of a typical failure load for the sample-shim combination.  In this case the test was run to 4800-lb.  The test result is shown here.

Test-B: The initial test was disassembled and then reassembled in the same position.  The sample was again run to 4800-lb.  The test result, which is nearly identical to Test-a, is shown here.

Test-C: Test-B was disassembled and then reassembled in the same position.  The sample was to run to 4800-lb a third time.  The test results, which are consistent, are shown here.  

Test-D: Test-C was disassembled and reassembled a third time, in the same position.  Unlike the first three tests, the sample was run until it reached its maximum load carrying capacity.  The test results are shown here.  

Test-E: The test samples were reassembled a fourth time.  Just like in Test-D, the sample was run until it reached its maximum load carrying capacity.  The test results, which show a 7% increase in Linear Coefficient of Friction Load are shown here. 

Conclusion: A DC shim can be re-installed multiple times and still yield reliable results.