Had to drill holes in some thick wall stainless steel stanchions. Quickly learned the sundry drill bits I have suck. And I even have cutting fluid.....
What is a good/very good/freakin awesome fractional drill bit set up to 1/2"?
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Had to drill holes in some thick wall stainless steel stanchions. Quickly learned the sundry drill bits I have suck. And I even have cutting fluid.....
What is a good/very good/freakin awesome fractional drill bit set up to 1/2"?
The fact that you're dealing with stainless probably has as much, if not more to do with your difficulties than the shitty drill bits do.
Fun stuff.
Cobalt (or carbide of you have the machinery to use it).
Speed and feed is crucial. As soon as the bit stops cutting and starts rubbing you're kind of screwed.
oh snapQuote:
Originally Posted by Tricky Mike
kinda
Irwin Cobalt?
I'd like to find a good set of reverse twist bits for screw/bolt extraction
If you are using a press and securing the part, carbide. If you are using a hand drill or the part can move, carbide tipped.
Small drill press.
If you're using a hand drill (which I'm assuming you are) then hsco (high speed cobalt) with a tin (titanium nitride) coating is going to be your best bet. If you have access to a drill press it is going to make all the difference. Feeds and speeds as mentioned are going to be crucial. So the rpm of the drill and how many inches per revolution the drill is going into the work are the controlled factors. On a hand drill you aren't really going to be able to control them that well.
The other thing you're going to want to think about is the drill point angle. Most drill point angles (general purpose) are 118° included angle. For harder materials like stainless you're going to want an included drill point angle of 135-140°. This is in part because for drills of the same outside diameter a drill with a greater drill point angle is going to be cutting less effectively because the hypotenuse (cutting lip) is shorter. It therefore requires less torque to operate and will generate less heat.
Here are some examples. These are bright finish (uncoated) because the TiN coating made the price jump up to $300+, and I am guessing that is more than you want to pay.
15 piece kit:
1/16 to 1/2", 135deg Point, Bright Finish, 01196153 - MSC
29 piece kit:
1/16 to 1/2", 135deg Point, Bright Finish, 63323570 - MSC
I got the pilot holes drilled (using a small drill press) and some of the larger ones. Think the speed was right, and used cutting fluid.
These are the bits I plan to buy unless anyone suggests something better.
29 Piece Cobalt M-35 Metal Index Drill Bit Set - Tools - IRWIN TOOLS
Those are close to $100. Their really good ones are over $200.
Don't pilot drill in steel you will tear the corners off the drill. Just spot your holes and then drill with what you've got. What grade stainless is it?
Irwin should be fine for you don't go baller unless you are buying singles. You are on a time line drilling stainless.
As said speeds feeds and cutting fluid will do more for your drill life than baller drill brands. Assuming you are at least using a decent drill grade to begin with.
Oh and unless you are buying really good drills just get regular chisel points. Split points drill great but don't hold up as well.
Only used the Irwin bits once, worked well.
If you are going to spot make sure that the spot drill has an angle that is less than the drill. HSS drills like to be guided into the hole while self centering carbide units are more rigid so hitting center first is optimal.Quote:
Originally Posted by DaveZX6r
Garandman. I don't know if you drive past Lowell on your way up to Goshen. But industrial tool supply has great prices and alot of really good people.
Industrial Tool Supply - We make it happen!
We get all our stuff there. You may get a better value just telling them.what you need and getting a quality import set rather than buying an Irwin set. Also if you know you are going to be drilling a bunch of the same size you may be better served just buying a sleeve of them rather than a full set. As soon as you start ss your kind off on borrowed time for that drill.