Drill bits for stainless steel

[NickWelford]

I need to make some holes in some 1mm stainless sheet. Not sure my drills are up to it for more than a couple. Any recommendations for decent bits that won’t be blunt in no time?

 

[TFrench]

Dormer are good, we use RECA at work but I think they are trade only. I've used the erbauer ones from screwfix in the past and had no issues. Use plenty of pressure and a bit of cutting oil if you can and it will be fine. I get literally hundred of holes out of a bit (3.2mm for rivets) in 0.5mm stainless.

 

[John Brown]

I think I may have mentioned this before, but a person I worked with many years ago used a centre punch sharpened to a triangular point for SS. He said it didn't work garden the SS as much as a conventional punch.

I can find nothing about this on the web, but he was a trained toolmaker, and a very competent classical guitar player.

 

[Cabinetman]

I think John meant work harden, isn’t this predictive thing wonderful!
Another point about drilling is that you must go slowly, as in the drill must turn very slowly or else your bits will just be ruined, as was said the Erbauer ones from Screwfix work fine.
If you’re drilling small bits you must cramp them down to avoid injury. Ian

 

[Jelly]

I need to make some holes in some 1mm stainless sheet. Not sure my drills are up to it for more than a couple. Any recommendations for decent bits that won’t be blunt in no time?

Really Sharp ones, running at the right speed for your hole size and a consistent amount of feed pressure.

I've never found brand to have much bearing on how well a drill cuts, but I have found that in work-hardening materials sharpness is everything, and maintaining adequate feed pressure for your cutting speed makes more of a difference to maintaining a sharp edge than anything else.

Cobalt drills generally peform better than standard HSS or Coated Bits, but if you don't maintain a good chip thickness, they'll still blunt in no time.

Same story for carbide drills, they're able to maintain an edge better than Cobalt, but with incorrect feed pressure from the start you'll likely chip the whole edge off the drill as it suddenly bites into the skin of work-hardened metal in the hole.

You should be aiming to run at slowish speed and relatively high feed pressure. If you accidentally harden the hole and it stops cutting, you can break through that by using a much higher speed and light pressure but will need to sharpen the drill immediately afterwards (I do this on an offhand grinder checking against an angle gauge with a hand-lens, it takes some practice, but it's dead cheap and the results are pretty good).

 

[John Brown]

Yes. Harden. I really struggle with phone typing!!!

 

[Spectric]

I used to use drills from Swiss tech, they were shorter than std, spiral fluted and had Cobalt in the HSS , used them on inconel so stainless would not be an issue.