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Drill bits for cutting through 1095 steel


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Can anyone recommend some drill bits that can cut through hard steel like 1095  1/8 inch thick?  I am struggling to make some holes for the pins I want to put in my knife handle. 
 

I use a fairly powerfully hand drill and I’ve easily made holes in mild steel and rebar, but I’ve recently tried working with better quality steel like 1095 but have had no luck with the bits I have or have bought. 
 

I always start with the smaller bits and work my way up to a 5/16 diameter drill bit but I can’t get the bigger bits to drill through the metal.

 

any suggestions or help is appreciated. Thanks

 

btw this is the last set of bits I bought

moolo Hex Shank Drill Bit Set (16 Pcs), Premium 4341 HSS Titanium Impact Hex Drill Bits for Wood, Steel, Metal, Plastic, Quick Change Design (1/16”-3/8”)

Edited by MageDK
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The steel I bought was 1095 Hot Rolled Carbon Steel 1/8" x 2", 12" bar, Knife Making Stock, Billet

im not familiar with all the terminology yet but does hot rolled mean it was hardened already?

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  • 2 weeks later...

Sometimes drilling thin stock is a pain. Even mild steel can work harden when drilling. Heres a few suggestions.

Drill a single pilot hole, then go to your final bit. Make sure the pilot hole is a little bigger than the flat on your final bit. 

Ease up on the downward pressure. Too much creates heat and this will cause your work to harden. 

use cutting fluid or even water when drilling small pieces. Apply the fluid before you start to drill. Otherwise it may harden your work when drilling. 

If it hardens, anneal as was stated above.  

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I did try annealing it and that helped a little.  I was able to get a little further with the drilling, but then it hardened up again.  I was able to work the hole a little larger with a small file.

I am trying a few different options of cutting oils and lubricants on some scrap pieces to help ease the heat while drilling.

 

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Bosch M42 Cobalt drill bits will go through annealed/hot rolled/normalized 1095 with ease. I'm sure there are other brands that would do the same, but I've used these so I'm willing to recommend them.

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Although the "obvious" thing to do is to look for "better"/harder drill bits, the problem is not usually with the drill bit, but with the rest of the setup, In My (limited) Experience.

Very few handheld drills run slowly enough for drilling hard steels. The hardness problem is not usually "just" the hardness of the steel that is about to be drilled. Work-hardening often enters into the equation as well. 

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When you look up the feeds and speeds for drilling, there are both values, feed and speed, given. "We" can usually take the speed with a pinch of salt and run a lot slower, as the values are given for production scenarios in which time is money. It is certainly unwise to run faster. 

The feed is important for work-hardening materials. Each pass of the cutting edge does work as it cuts and leaves a thin work-hardened layer on the workpiece. If the feed is correct, the next pass of the cutting edge will get below this thin work-hardened layer and cut the un-work-hardened material beneath. Turning slow and feeding hard with a drill-press is the best approach for most of us. Using a hand-held drill, it can be hard to maintain enough pressure to get the feed necessary. If the drill stops cutting, even momentarily, it will skate on the previously-cut surface with the feed pressure spread over a tiny area at, and just behind, the cutting edge. This high-pressure contact will cause further work-hardening and the problem will swiftly escalate. Many of us are impatient, bloody-minded types and will persist in trying to drill after the drill stops cutting.

If you have no option but to use a hand-held drill, use the slowest speed you can, watch the swarf and IMMEDIATELY stop if the drill stops cutting. Either sharpen the drill (a skill that is well worth acquiring) or replace it with a new one, then start again. 

IME, the only "better"/harder drills that work well in a handheld drill are TCT drills intended for use on Stainless Steels (which work-harden very readily) or Hard Plate (here in the UK, I've bought them from locksmiths when I've run into the problem when out on sites, but they really know how to charge). Cobalt drills do work a little better than vanilla HSS, but they also tend to be more brittle. The improvement is significant in a rigid setup, but there is a high probability you'll just break them in a handheld drill. Solid Carbide is even worse for breaking when used in a handheld drill (though truly superb in a rigid setup). The TCT ones have the hard tip, but a tough shank and flutes, so are a good choice in a handheld drill.

 

 

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Keep an eye out for a deal on a drill press. More often than not trying to drill steel with a handheld drill ended in frustration and an unfinished hole for me. 

Pnut

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Any good drill will work for cutting 1095, a quality drill not the ones you find for $5 a package. 

Heat is your enemy. You need to drive the drill slow enough so that the drill does not over heat and loose temper. This will cuase dulling, but must move fast enough to cut the metal and get the chip out. If the metal overheats it will work harden. The goal is to keep the heat in the chip and get it away for your work. So the cut will have to be deep enough for the chip to be big enough to hold that heat. 

Most likely, like others have said, a hand drill is to fast. You are needing about 50 feet per minute feed rate. That will translate to around 600 rpms on the drill. Also a drill press is much prefered becuase you can keep constant pressure and alignment of the cutting edge of the drill. 

There are fromulas out there to help you figure these things out. Easily available on line. I just inputed "speed and feeds for 1095 steel" and got a whole table of feed rates for all types of steel. 

RPM = (12 x feed rate) (50 in this case) / (3.14 (pi) x diameter of drill) (5/16, .313" in this case) 

12 x 50 = 600

3.14 x .313 = . 928"

600 / .928 = 646.5 

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All good points mentioned earlier. I would like to add two things: 1. Watch for even chip formation from both cutting edges - if not a sign of one edge dull. 2. Listen to the sound of the drilling action- if it does not sound right e.g. high pitch screeching, crunching etc.- stop and check the cutting edges.

 

 

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