Have you considered a LEEB hardness tester? (as they tend to be more portable) - the material would have to be faced perpendicular to the LEEB head, and have no 'jitter' when hit. - if you must have a conversion from the LEEB results to a Rockwell number, then it'd be prudent to check to see if there are conversion tables for your material-under-test in a standard like ISO 18265:2013 and ASTM E140 If one is considering testing a failed or unfailed rockhammer's haft, one may consider that the hardness of the surface is not necessarily going to be found to be a constant throughout the body of the haft. (by way of analogy consider san mai knife construction, where a hardened core forms the center and cutting edge, but is surrounded by a softer pair of outer layers for durability and resilience.) Possibly consider ultrasonic, eddy current testing, and/or radiographic analysis, as they give a 'look inside'. Rockwell (and Leeb) give an assessment of the surface, but in non homogeneous construction, a fatigue failure may well be due to internal defects/material choices. BITD, I was taught to look only any external defects/failure modes after verifying the internal/core integrity... but I didn't go the ME route, so that 70's era advice should be taken with a giant grain of salt. All that said, I have a LEED unit but it's probably out of calibration (from 2018) and it has been abused (by me) in testing very small, non-flat objects... off-perpendicular strikes puts off-angle forces on the striker head/arm and probably wears on the surfaces used to guide the straight-strike. I didn't look into a replacement after discussing my ultimate target with my nephew who is a genuine expert in the design, predictive software modeling, and manufacturing in the 'exotic materials' world. To analyze a failed hammer, I'd first look to ultra-sonics, then radiography, then eddy-current... plus a great investment in time w/visual inspection using magnification in the 10-500x range. Getting great data on surface hardness and extrapolating it to the bulk mass/core may not reveal the actual cause for failure. If you have a friend who works for Boeing or Lockheed or General Dynamics, etc, ask how they do mechanical failure analysis... they are a great resource. Seriously: good luck in determining how/why these hammers fail.
1 month ago
| 6
Are we testing a certain brand of hammer that now says it will break if used to hit rocks?
1 month ago
| 6
Do you need a full machine? I've used them in my trade. There are handheld versions available that cost significantly less than a machine.
1 month ago
| 3
Currently Rockhounding
Does anyone own or have access to a Rockwell hardness testing machine and would like to work with me on a project?
If so, please email me at currentlyrockhounding@gmail.com
(A photo of what these machines look like for attention)
1 month ago | [YT] | 24