How to drill through hardened steel??

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Andre68

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trying to drill through some hardened steel parts I bought, didn't know they where hardened steel. I just can't make a dent in these things.

Anyone have any tips for drilling through hardened steel?

I took it to my local fabrication shop and they said they can't do it because it's hardened steel. But I do in fact need to drill 1/8" hole in these parts I bought. So any tips will help
 
How accurate does the hole need to be? If it doesn't need to be super accurate, try finding a shop that has an EDM. It essentially burns a hole through the metal using a vibrating hollow tube that arcs and slowly burns away the metal. The shop I worked at many years ago had one for removing broken taps & drills. Many people thought it was a laser, but it's not.

Electrical discharge machining - Wikipedia, the free encyclopedia
 
Here's some photos of the piece.

I believe I tried a carbide bit. Nothin

image.jpg


image.jpg
 
cudascott said:
A carbide bit should do the trick
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Bingo. Carbide will be your best bet if it's an extremely hard steel, but make sure to use a drill press. Using a hand drill and carbide bits is a recipe for snapping a bit. Depending on how hard it is, a new cobalt bit might do the trick as cobalt tends to keep it's cutting edge longer than HSS.
 
When I tried the carbide bit I simply used wd40 for the bit. Could that have been the issue? I was told I need legitimate cutting oil?

Also I don't have an actual drill press but I do have this old style one I bought at the swap meet. You think that can work?

image.jpg
 
Cobalt bit, low rpms and lots of cutting fluid will get it done unless it's a really high HRC.
 
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Such a tiny part, I would anneal it, drill hole, then re(surface)harden.

Torch it red hot for awhile, then let it cool down by itself.
Drill hole
Reharden by torching it red hot again and dunk it in water.
 
Agree on annealing it. I heat red hot and cover in lime to slow the cooling down, dirt or sand would be a good bet too. Sometimes I have to double anneal.

That "drill press" is better than nothing, but you really need something with some leverage and a vice to hold your part stationary.

And most hand drills turn to fast for serious metal work. Slow it down and you will do much better.

Best,

CE
 
Cool so get the part red hot and then drill the hole? Or heat it first and let it cool and then drill?
 
Andre68 said:
When I tried the carbide bit I simply used wd40 for the bit. Could that have been the issue? I was told I need legitimate cutting oil?

Also I don't have an actual drill press but I do have this old style one I bought at the swap meet. You think that can work?

View attachment 1714958848
Click to expand...
that my friend is not a drill press in the manner you need to be using...you need to be able to go at lower speed than a hand drill usually will operate, based on the all metal housing this drill is likely not variable speed. little light in the loafer for serious drilling procedures..
 
Andre68 said:
Cool so get the part red hot and then drill the hole? Or heat it first and let it cool and then drill?
Click to expand...
If you want to anneal the piece get it cherry red then place it in some vermiculite. The slower you let it cool the better, an hour or so? With large pieces of high carbon I let them cool over night. You can then drill the hole with ease. If this is a piece you need hardened again you would need to know the steel composition to correctly heat treat. Roughly 1550 F for Austenite then a quick quench in heated oil 150F would most likely work for you. You will also need to temper the piece after that so.... 400f for an hour in the oven should do the trick. This may be more trouble than it's worth. I would be tempted to zap a hole with a plasma cutter if the hole diameter wasn't critical.
 
I would get a good stone and use a die grinder if it is super hard use a green silicone stone but be careful these stones are soft .
 
Solid carbide bit and a decent drill press. Just take it to a shop as it would cost you as much to buy the bit. This guy is drilling hardened plate with the SC bit.
 
Andre68 said:
trying to drill through some hardened steel parts I bought, didn't know they where hardened steel. I just can't make a dent in these things.

Anyone have any tips for drilling through hardened steel?

I took it to my local fabrication shop and they said they can't do it because it's hardened steel. But I do in fact need to drill 1/8" hole in these parts I bought. So any tips will help
Click to expand...
wrap a little hair around it :)
 
Sharpen a carbide tipped masonry bit like you would a normal drill. Drill fairly slow.... I've drilled 6"+ thick hardened tool steel with a masonry bit and an air gun for cooling, many many times. Carbide doesn't like the shock of cooling intermittently with water, so unless you can keep it flooded, just use air.
FYI A 1/4" masonry bit is larger than .250". Just grind the sides of the carbide until you hit you desired diameter on a bench grinder. Easier done with a green wheel but can be done with a standard wheel.

Edit. Sorry, just noticed you wanted a 1/8" hole, but the same info still applies.
 
Find a tool and die shop that has a sink EDM or EDM drill. I have both at my work if you wanted to pay the shipping I would do it for you.
 
how about telling us exactly what the hole is for. maybe there is an alternative to what you are trying to achieve.
 
First, I can't believe a fab shop couldn't put a hole in it...Are you trying to drill in the center of that depressed area? Depending on how the bit hits that it may just not be able to get started. I've seen that happen in mild steel. Center punch and try from the other side. A sharp bit and Tap Magic...
 
Also, if it doesn't need to be exact, a quick single shot with a plasma cutter can be used to make a small hole
 
Cobalt...Slow....One half size down then your finish size....I use an Ice Cube to keep it cool...
 
Don't use WD. Wrong application.

Keep the parts clean, go slow, use compressed air to keep things cool. You'll need to hold the part steady and apply a bit of force to get the bit to cut. It's not rocket surgery, but is all in the technique.
 
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