None of the common bearing steels that I'm aware of would have a composition with that much carbon in them, especially without any other alloying elements. My first guess would've been similar to IRstuff, in that 52100 typically has spherical shaped chromium carbides distributed throughout it...
Depends on how accurate you want. An angle grinder will absolutely do it with an appropriate abrasive cutting wheel. The accuracy will be limited to your manual operation though.
You can, it's not great but it can be done. I've milled a flat on a bearing ball using a full carbide end mill. You have to be very careful with your feed rate and accept that it might kill the cutting tool.
Grinding would absolutely be more suited for this application if you can find equipment...
We had a long standing disagreement with a supplier of ours about hardness values on heat treated 4340 barstock. In the end, the root cause was that they were using a dry abrasive cut-off saw and not grinding enough material off, resulting in lower hardness values. When we would cut a section of...
As hardness increases, the size of the indent gets smaller and you need less material to make sure you're not poking through the back into your anvil. So a soft material needs more thickness to minimize any errors caused by going through the test material. A harder material is by definition more...
We use air gaging on all the final ID/OD measurements for our bearings. Roundness and other measurements use different gaging but diameters are covered very well with air gaging. As btrueblood mentioned, you do need a lot of capital to measure a wide range of sizes though.
Have you evaluated the parts for carbon content at the surface? This could help determine if the hardness your seeing is due to carburizing being ineffective or slack quenching.
Regarding the hardness scale, I assume your measuring micro-Vickers on a cross section. This has been properly...
What do you mean by backlash in the bearings? I've never heard backlash used in relation to bearings, only gears and such... Do you mean radial/axial play? This can mostly be removed with adequate pre-load. I'd recommend that you pick a bearing manufacturer and talk to their technical sales or...
Why don't you update the job cards to have time/temperatures/tolerances to ensure repeatable performance across shifts? If you know that it needs to be 525C to get the hardness into customer requirements, why not update the job card to say 525C ± 5C? Rather than worrying about reworking previous...
That's interesting. I work at a sub tier supplier and our parts end up at Boeing (among others) on the 737s. We happened to have our quarterly all hands meetings yesterday and there was a long discussion about the 737 Max issues. We were told that our customers have contacted us and assured that...
I'm with dbooker630, can you section a part and investigate the microstructure? If not, can you find a lab that can. That should help narrow down where the problem is.
The screw vs. bolt thing has always bothered me because I feel like it should be more clear than it is, but that's what we get over years of use.
The last time I looked into a definition for them, what I found said that a screw threads into another part whereas a bolt goes through something and...
MEchase,
Mostly they're directly tied to the aerospace industry and the Nadcap compliance specifically in there but they do have a fantastic course on Root Cause and Corrective Action. I really like the deep dive mentality that goes into their course. I think it's really easy to cop out too...
It's pretty niche stuff but if you're in the Nadcap world, I think their eQualearn courses are excellent value. I learn new stuff any time I go to one and I encourage anyone who's involved to try out some of their trainings.
