I had decided to drill a 1" hole in the middle of the loader bucket in the middle of the cutting blade edge. I figured I could dual purpose this with a trailer ball for moving trailers around the yard as well as a D-ring for chains when doing some lifting and pulling. I brought home the mag-base drill setup from work which in normal conditions should put a dozen 1" holes in steel in less than an hour. I only wanted 1 hole and thought this would be a quick task. But of course everything on a 45 year old tractor turns into a half day project. (Or at least that what the wife says). I believe there are at least 3 layers and I have gotten thru 2 of them in a few minutes. The 1st was the bucket itself which is ~5/16" thick and fairly mild steel. The 2nd layer was about 3/4" thick and slightly harder but still cut ok. The 3rd layer which should be about 3/8" thick seems to be harder than a whore's heart and has dulled 2 brand new coring bits. So the question is: What are the cutting edge/blade made from? I am sure this isn't OEM and after 45 years who knows what farmers have customized this thing with who knows what, but in your vast experience what is the cutting edge usually made of?
Cutting edges are usually made from one of the AbrasionResistant steels like AR500 and will have a hardness of rc30 more or less could be a few other things too. I see in your pics what looks to be dirt/sand/rock in between the layers... When I'm mag-drilling if any dirt at all gets in the cut you can pretty much toss the annular cutter.
Spot on Rinsii! Dirt is this fastest way to dull anything. Best example is a chainsaw. One dip into the ground will toast a new chain and that is exactly what happened here. I cleaned out the hole real well and went at it with the last 1" cutter I brought home. This time I did better about keeping it clean and not just blasting thru. Success!
Just take a torch and finish a burn thru
Good to hear you had success!!! I have actually done a few holes similar to yours with the multiple layers... and there seems to always be dirt in between the layers, it's like whoever welded it last didn't clean anything off!!! My latest mag-drill has a coolant connection which works great to keep the cut pressurized for getting rid of cuttings and keeping contaminants out