Drill bit for stainless steel

[mjsnodgrass]

I have a broken off bolt in a frame. I want to drill it out and re-tap it. It is a half inch bolt. It appears that the bolt is stainless steel. I’ve tried various drill bits and it doesn’t even touch it. Can anybody recommend the proper drill bit for removing this bolt? There were four bolt broken off. I was able to get three of them, but one of them will not drill out. I can’t use heat because the frame is recently painted. Any suggestions?

i've had good luck drilling s/s with a drill bit used for drilling tile. bought it at HD. had kind of a triangle shape to it if i remember right. think the dia was 1/4 in. good luck

 

[Ultradog MN]

What are you using to power the bit?
Slow enough speed makes a huge difference too.

 

[Pembroke]

just a question: have you tried kroil and let it set for a few days and then more of this oil and then try to drill with left handed bit.

 

[montidale]

What are you using to power the bit?
Slow enough speed makes a huge difference too.

When I get a chance, I’m probably going to use a Milwaukee battery hand drill. I do have a drill press, but I’d have to get a couple of my kids over to help me hold it on the press. That will be my last thing to try.

 

[montidale]

just a question: have you tried kroil and let it set for a few days and then more of this oil and then try to drill with left handed bit.

I was able to get a vice grip on it and try turning it in and would not turn. I tried chiseling it. No luck. I can’t use penetrant oil because there’s fresh paint on it. I guess my best option is to drill it out and retap it.

 

[Russ from MN]

The preferred coolant for stainless is very light, In the old days they used turpentine. We used a special coolant called key-tap, it's very light. It doesn't seem to be available anymore, but I'm sure there are others, I see something called tap-magic that comes in a flat can like key-tap did. We used a lot of stainless in the paper industry.

 

[will-max dairy]

If this is the only time you expect to need to drill stainless, my vote is to get the proper sized carbide bit, or a couple of them.. and work slowly and carefully with whatever drilling fluid you have, I've used vegetable oil. If you want, you can probably buy a cheap, fine diamond knife sharpener pad to go with them... and give them a couple of rubs here and there, holding the angle by eye... to spruce them up... but... probably not needed.

If you plan on making a business out of regularly drilling and tapping multiple holes or many stainless fasteners; maybe then the time to learn how to sharpen bits... or learn the nuances of drilling stainless with various HSS/cobalt/whatever bits.

 

[560Dennis]

I would recommend nachi spindle drill of correct size

 

[buickanddeere]

Chuck it in a milling machine and cut the bolt out

 

[mjsnodgrass]

What are you using to power the bit?
Slow enough speed makes a huge difference too.

i was using a milling machine