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

[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...

[DocsMachine]

It doesn't matter how hard the material is, there's always something harder you can use to cut it.

For tough steel, as the others said, sharpen the bit to a shallower lip angle, dark cutting oil, slow spindle speed, heavy pressure.

If you have a good tool supplier, spring for a carbide "jobber" drill, and use it in a drill press. (Carbide tends to be brittle, and can crack if not in a rigid setup.)

For evan harder steel- like a tap, or easyout- a solid cobalt spade bit in a strong drill press will cut by literally heating the base metal to red hot by friction, and wiping it away in softened strings. I've drilled through files and the shank of an endmill that way.

Doc.

[Ten Hammers]

I have a hammer stand for the trailer shop. Standard ( worn ) 16 " disc blade for a base and some 1 " pipe for the upright. 3/4 " insert and a collar and bolt for the riser and a ring on top to hold the hammers. The 1 "pipe has ( had ) a 3/8 mig fillet weld. Over the years the disc cracked away from the weld and finally broke at Midwest Old Threshers this year. I acetelyne welded it back together with good success. Higher carbon ( like disc blades ) will crack when welded sometimes. My weld was intact ( on the pipe and not cracked ) before I tacked it back with the torch and made the new weld adding some rod. I am hoping that the problem is solved and I feel confident in the stand. I had good fusion on the disc with the fillet weld but the disc cracked away.

[ThomasPowers]

Cracking in the HAZ, (Heat Affected Zone), is the bade of welding high carbon steels. A good preheat and post heat will generally solve that problem. Welding processes that put more heat into the piece also can work.

What is happening is that somewhere in the HAZ there is a point where the heat from the welding and the *quenching* from the cold body of the metal meet just right to actually produce a hardened and brittle zone that does not get tempered and so is quite brittle and fails; not in the weld, but in the HAZ.

[Ten Hammers]

interestingly enough this is the first issue I have ever had with a weld cracking away from parent metal. I have several other stands with disc blades for bases. This stand lives in the trailer and also lives standing upright ( with the top of the stand removed and placed over the base for space management. No weight other than the stand. Highway vibration perhaps, dunno. I have yes seen welds torn away from parent metal but this is the first time I have seen one of my welds do this.

[Jim Black]

Try heating the spot that you want to drill red, place some sulfur on that spot, and let cool.Then center punch and try drilling.

[Dodge]

I worked with drills for a few years, both manual and automatic, including CNC. I have found that a constant feed appropriate to the sized bit and material being drilt (won't work in Scrabble, but I like it) is most important. Good bit + good speed + wrong feed = disaster. Too slow = high production cost. Too fast = bits for lunch.