Drilling stainless steel

Is there any special drill bit or procedure that needs to be followed when drilling into stainless steel?

Reply to
Lawrence Zarb
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Sharp drill, low speed, firm pressure and oil.

Reply to
John

What grade? If it is an austentic steel, it drills much the same as any steel. Austentic grades are usually identifed with numbers in the 300 range, although the older 18/8 and 18/10 are also used*, and they are non-magnetic. Hardening stainless steels will glaze quickly if you do not keep up an even feed rate, which can make them difficult to drill by hand. Once that happens, you are going to have a seriously difficult time drilling any further. The most common hardening grades are martensitic steels, with numbers in the 400 range, and those are magnetic.

Tool manufacturers supply selector charts, to give you the correct speed and feed rtaes for different materials and you can order one from

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the links to drilling and then selection of speeds and feeds to order a copy.

  • There is also a range of BS EN ISO numbers, but they are so complex that, in practice, they are not used much.

Colin Bignell

Reply to
nightjar

Use a Cobalt drill bit, slow speed and oil

Reply to
Trev

You can use a decent quality HSS drill as well. Start off with a small/pilot hole, then increase size of drill to full diameter you require. Oh, yes use plenty of cutting fluid as well. DO NOT use too much pressure or you will quickly blunt the drills.

As I have only 35 years experience in engineering I don't know what I am talking about! so you are free to ignore this.

Reply to
Bob H

Plus, there is stainless and stainless, it varies from "what are people going on about" to "I can't believe it's not diamond". The first can in some cases also convert into the second, if you don't press hard enough, and the drill gets to rotate without cutting. Or if the drill is slightly blunt. IMO, if you've only got a few holes to drill, too much pressure is better than not enough.

Also, high speed on an electric drill should not be used for any but the smallest drills.

Reply to
Ian Stirling

Yes there is 'stainless' and 'stainless'. There is, if I remember correctly 18.8.1 and 18.something else.1. I think the 'something else' might be 13.

Its been about 5 years now since I had anything to do with that. Cutting fluid is the key here tho'

Reply to
Bob H

A good bit and low speed drill is certainly nice, but we dont all have them lying around, and neither is actually necessary. If youre using cheap bits and an ordinary not so low speed mains drill, it is necessary to take the bit off the workpiece frequently and let it cool off. Otherwise the end simply starts to soften, and your drill bit's history. This simple workaround makes it possible to drill steel with any old kit.

NT

Reply to
N. Thornton

White Spirit as cutting fluid,for SS

DO NOT use too much

Reply to
bob

The numbers can have a very wide range, as they represent the percentages of chromium and nickel in the steel. However, the most common are 18/8, a bog standard stainless steel, and 18/10, used for food, chemical and marine applications. If you were using 18/13, you were probably doing deep drawing work. However, all those are only a small selection from the austentic range of stainless steels. There are martensitic, ferritic and precipitation hardening (a special type of austenitic) stainless steels as well. The ISO standard runs to several pages of tables of different specifications.

Colin Bignell

Reply to
nightjar

Hi Colin, well like I said its about 5 years since I had anything to do with stainless steel. The industry I was in was chemical, and they needed 2/3 types of stainless to use in the pipes and tanks, but for

*general* use I used 18/8 I think. We also used 'sten something* for some drilling jobs. I have nothing to do with it now and don't really want to either if I can help it.
Reply to
Bob H

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