[Dick Mahoney]

what kind of a drill bit will cut thru stainless

[BTxpress]

what kind of a drill bit will cut thru stainless?

A Kobalt bit @ a low rpm.

[Fullthrottle410]

cobalt, using some type of cutting fluid would not hurt either

[PatrickMead#13]

Low speed and magic tap cutting fluid. Always had good luck with that stuff

Posted via Mobile Device

[nieftsr]

Originally Posted by PatrickMead#13 Low speed and magic tap cutting fluid. Always had good luck with that stuff Posted via Mobile Device

Any bit will, as long as it is sharp, I work with stainless all day long, the best way is to step it up, if your wanting a 3/8's hole, then start with a 3/16 bit and step up to a 5/16, then a 3/8's. stainless is soft and plyable not so much hard. most think it's very hard.. Hope I helped.

[racen857]

As a machinist I will agree with the last post, with one change you really can go from the 3/16 to 3/8 in one step.

What hole size are you drilling? I can give more and better info.

[TQ29m]

Never really had stainless challange me that much, just slow and easy, but the past month I've talked to several guys that have had trouble drilling it, for nerf bars. I don't use my best drills for it, cause it can snag and break one pretty easy, but I have a set I got at Big Lots years ago, that don't know the difference, they were hi-dollar too, probably the $3.99 set, course they were made from our best steel, that we sent across the pond, stainless is odd to work with, it is tough, but the main thing is slow, around 300 rpm is plenty fast. Bob

[racen857]

One other trick when drilling something that is hollow like nerfbars. Is to use a cordless drill that has adjustable torque settings. Take it off the drill setting and back down the torque abit. Then if the drill catches the drill will slip and help to keep from breaking the drill bit.

[Dick Mahoney]

thanks I bought cobalt 3/16 bits

[DAD]

Originally Posted by Dick Mahoney what kind of a drill bit will cut thru stainless

I got here because I was wanting to see what a guy named niefster was writing about in the past. I see he also admits to be a sheet metal man or machinist.

The answer to the drill bit selection is any sharp bit made of hs steel or better.

Stainless is a poor choice for nerf bars. The use of stainless came about because of good old Uncle Sam and his EPA. They in their wisdom decided that the chrome plating process was just too dangerous for us common folks to use and more or less regulated the chrome plateing shops out of business.

In the past 4130 was the choice for bars and then have them either cad or chrome plated. 4130 is much stronger than stainless and withstands racing events much better than the softer stainless steel does. This change away from 4130 didn't bother the chassis builders too much because now they could sell a lot more nerfs and bumpers to us racers. I still have my nerfs and bumpers made from 4130 and catch hell from AJ everytime I put in an order for them. I don't plate them anymore I just use the same surface protection I use on my frames, good old WD-40 by the gallon. They last a whole lot longer and nothing is prettier to me than good old Mill Finished 4130.

Now getting back to drilling. Any machinist worth his salt would tell you that when machining the two most important factors are "SPEED AND FEED". Each type of metal has it's own values of speed and feed that a good machinist will try to adhere to. Stainless requires a slow speed to keep the cutter cool. It also requires a rather rapid feed, (you got to advance the bit into the metal fast, lots of pressure.) If you don't the bit will slip on the stainless and dull the cutting edge and even turn it blue from excess heat if you are not carefull. like a strauping strap at the barber shop but in reverse.Thus no hole.

Tubing presents another problem. It is not flat on the underside of the hole and the drill bit drills through the center portion of the tube long before the outer cutting edge of the drill reach their end of the hole, making the drill bit grab and tear out chunks of the drill bit.

If you can make wooden dowel (Home Depot) that fits tightly into the inside of the tube it will catch the drill bit and slow the feed down enough to help prevent this tearing of the cutting edges of the drill bit. It will also help if you to drill from both sides of the spud and using a good cutting fluid that has some carbon-tet type chemicals in it to help carry away the heat from the cutting surface will also help.

I apologize I ASS-UMED this post was in the tech discussions portion of IOW!

Honest Dad himself