problem drilling this..

[Candidquality]

I am trying to drill through this disc and it's not cooperating. Can anyone tell me what it is made of or where to find out. I've tried a few searches, but don't know diddley about these so i'm having no luck.

thanks,
James

[jimmy seale]

carbide or cobault drill bit,maybe-ot heat and punch,best of luck,jimmy

[Glenn]

You may have finally located a properly labeled "MM" piece of mystery metal.

[irnsrgn]

a very slow drill speed with constant pressure and lots of dark thread cutting oil will do it. if you slack off the pressure any the bit will glaze over the material and a resharpen will be necessary. also regrinding the bit to a lesser angle will help some. remember you need to start under pressure or it will glaze at the start. You can also use a carbide tipped masonary bit at slow speed but you must keep it cool with a constant stream of water or the heat build up will melt the silver brazing used to cement the carbide in the steel shank. The material is more than likely high carbon steel.

[Ten Hammers]

I am going to agree with Junior. This is ( for me ) a place where the post drill may excel. First question is will a center punch dent it ? 2nd question is ( then ) will a sharp good quality bit start cutting ( under good down pressure ) afterward ? I have drilled recip power hacksaw blades ( not bi-metal ) with the post drill. The are not really thick ( perhaps 14 ga ) but still tough chewing. I load the bit with pressure and flood with cutting fluid. The post drill can turn at whatever RPM I turn it by hand and of course the stock is clamped to the table. The post drill has an automatic feed. My experience has shown that as long as the bit is cutting, the rpm is right ( to a degree, it can be too slow ). Most try and use too fast chuck speed. Good luck.

[Candidquality]

Thanks, worked like a charm. Still curious as to the makeup. Are most disc's high carbon steel? I'll do some Hardness testing on it in a bit. but a punch easily marked it.

[ThomasPowers]

Disc as in disking the field after plowing? Yes they are generally carbon steel and hardened to resist abrasion---especially ones designed for very sandy soils with no rocks. Use drilling hardened steel rules or anneal first.

Thomas

[the_sandy_creek_forge]

AND, they are very tough steel, as in resistant to chipping/cracking (if you ARE talking about discing type discs). We made a couple tomahawks out of them once. They hold only a blunt edge (not very hard/brittle) but you'd be VERY hard pressed to make that blunt edge get dull on ya! (and it was a simple cut, bend, weld procedure making them).
-Aaron @ the SCF

[ApprenticeMan]

I KNOW of a very special type of drill that would drill that like butter.

[ThomasPowers]

Shoot I have drilled hardened pattern welded steel with a pure carbide bit before; there are several types of dtill that would do so...