Drilling Hardened 1/8" thick O1

[Rickoo]

So, I've changed my design after heat treating. I need to drill two 1/8"diameter holes in 1/8" thick O1. I plan on using a full carbide bit in a drill press, but am wondering the best RPM to use. And whether to use cutting fluid. My sense is slow and wet.

Any opinions on the best RPM to go with?

 

[Geoff Flato]

Fast as your drill press will go. Carbide generally doesn't like slow. Clamp everything as rigid as possible. Either keep it constantly wet with cutting oil or dry, nothing in between. Partial cooling leads to thermal shock which carbide also doesn't like.

 

[LARRYZ10]

I agree with Jeff and drill with mine dry. Larry

 

[JTknives]

When ever I need to drill somthing hard I hot drill it. Heat it red hot and drill it with a normal drill bit. Do it quick befor it cools off and it will drill through it like butter. Carbide works but it requires little to no runout. There is a really good chance that you will destroy that bit in a very short order and thy are not cheep.

 

[Michael Black]

A setup like Geoff mentioned works fine, I've done it a few too many times lol
That being said, I would like to re-emphasize his point about keeping everything solid. If you've got any chatter or wobbling at all, you are nearly guaranteed to blow out the bit.

JT, I'll have to give that hot drilling a try. Sounds more dangerous. I like it!

 

[Rickoo]

When ever I need to drill somthing hard I hot drill it. Heat it red hot and drill it with a normal drill bit. Do it quick befor it cools off and it will drill through it like butter. Carbide works but it requires little to no runout. There is a really good chance that you will destroy that bit in a very short order and thy are not cheep.

Won't that affect the heat treat?

 

[Ken H>]

You're only heating a small spot on the tang and HT doesn't really matter on tang. If drilling very close to ricasso, then put a file guide (or similar) to act as heat sink....... OR, perhaps wrap the blade in a water soaked rag to prevent blade from heating up.

 

[Robert Erickson]

I have been using carbide tipped drill bits in my drill press. They are more forgiving. I have runout in my drill press and like JT stated that will shatter carbide bits.
I get them from USA Knifemaker: http://usaknifemaker.com/carbide-tip-drill-bit-1-8-hard-steel-drill-bit-norseman.html

 

[jdm61]

Do you think that bit would work for enlarging a hole?

I have been using carbide tipped drill bits in my drill press. They are more forgiving. I have runout in my drill press and like JT stated that will shatter carbide bits.
I get them from USA Knifemaker: http://usaknifemaker.com/carbide-tip-drill-bit-1-8-hard-steel-drill-bit-norseman.html

 

[Josh Rider]

Do you think that bit would work for enlarging a hole?

I had to enlarge some holes. Used a carbide cutter in a dremel and it worked fast!

 

[Robert Erickson]

Do you think that bit would work for enlarging a hole?

Yes, I have used the 3/16" to enlarge a 1/8" before.

 

[Rickoo]

1/8 full carbide, high speed and dry drilled through easily. Thanks.

This got me wondering about drill speed for non heat treated steel. I've primarily used O1 but I'm sure I'll try other steel in the future. Any consensus on drill speed for different types of steel?

 

[Busto]

I drill steel that is in the annealed soft state...that goes for carbon and stainless alloys and run at 420 which is easy on the equipment and the bits and no issues with any of the steels. Slow is good with lubrication clean holes no chatter bits last forever.