Drilling holes in CPM steels larger than 1/2"

LCKT707

LCKT707

Joined
Feb 26, 2015
Messages
576
Nothing thicker than 1/4", but anything from CPM154 to S90V. Starting doing a lot of karambits and my old ways of starting the hole was to drill a 1/2" hole with my old cheapy drill press then use sanding drums until I slowly get to 1" lol. So, how do you guys do it?

Mill it out?
Huge 1" drill bit?
Water Jet?
Carbide Cutters?

I am open to all the info I can get to making this process quicker! Thanks in advance.
 
I think a step bit would work well for you. Something similar to these:

image_11970.jpg
 
I've used a hole saw. Lube it. Go slow. Work it by hand if need be. AAAAAAAnnnnd you can insert jokes here :p
 
LCKT707 said:
I tried an Irwin step bit and immediately dulled it at like... the 5/8" mark lol. They're an expensive mess up and I can't resharpen them :/
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You're probably going too fast.

The larger the tool, the faster it's travelling at the surface.


You can resharpen.

Just put it on your belt grinder, re-flatten that edge that bites.
 
12345678910 said:
You're probably going too fast.

The larger the tool, the faster it's travelling at the surface.


You can resharpen.

Just put it on your belt grinder, re-flatten that edge that bites.
Click to expand...

I was really careful with speed/feed/cooling/etc... I had a machinist friend of mine school me on the dos and dont's of drilling. I'll give a go at putting the flat surface on the belt sander. I want to say my issue was the cheapo drill press... a few rare times I tried to put just a 1/8th" hole through S90V and the tip immediately heated up (changed colors) and dulled lol.
 
ive not tried it on CPM, but I've used regular old Hole Saws on 1084/W2/52100 to good effect

gotta make sure the steel is fully annealed, and use plenty of lube with a slow drill speed
leaves a bit of a ragged hole, so plan on some cleanup
 
Purchase a "Silver & Deming" Cobalt Drill Bit in the size you are currently drilling. They are reduced shank so fit the drill press and Cobalt will cut like its going through butter. These will give you smooth accurate hole sizes that won't require additional filing or drum sanding just drill up to 1/2" or better. Check out ENCO https://www.use-enco.com/CGI/INPDFF?PMPAGE=34&PMCTLG=00
 
I use the step drills from Harbor Freight to drill S35Vn with no trouble. My drill press is set on the slowest speed it will go and I use lots of cutting oil.

Tim
 
stephanfowler said:
ive not tried it on CPM, but I've used regular old Hole Saws on 1084/W2/52100 to good effect

gotta make sure the steel is fully annealed, and use plenty of lube with a slow drill speed
leaves a bit of a ragged hole, so plan on some cleanup
Click to expand...

I've heard this as well but haven't tried it yet, as the Ace nearby just has standard cheapo hole saws and people keep wanting CPM steels that are harder to work with lol. One day I'll balls up and try it out, let you know how it goes :D

Busto said:
Purchase a "Silver & Deming" Cobalt Drill Bit in the size you are currently drilling. They are reduced shank so fit the drill press and Cobalt will cut like its going through butter. These will give you smooth accurate hole sizes that won't require additional filing or drum sanding just drill up to 1/2" or better. Check out ENCO https://www.use-enco.com/CGI/INPDFF?PMPAGE=34&PMCTLG=00
Click to expand...

These words and terms excite me! Lol Thank you for the link bud, I'll look in to grabbing a couple of these. I have a set of some "good sounding" drill bits coming with the new press but, they don't look as fancy as the ones you're showing.

Thanks for the advice/input everyone.
 
I wouldn't worry about that 2mm business.
I've used them on 1/4 inch thick 30 year old brass gland plates without a problem.
In a drill press they are the fastest, neatest and safest way because they won't grab in the hole.
You can always flip the blanks over anyway if they are too thick.
 
Busto said:
Purchase a "Silver & Deming" Cobalt Drill Bit in the size you are currently drilling. They are reduced shank so fit the drill press and Cobalt will cut like its going through butter. These will give you smooth accurate hole sizes that won't require additional filing or drum sanding just drill up to 1/2" or better. Check out ENCO https://www.use-enco.com/CGI/INPDFF?PMPAGE=34&PMCTLG=00
Click to expand...

Used in a keyed Chuck only. No go for keyless Chuck like Albrecht.
 
a vote for the hole saw :thumbup:

I'll drill up to 3/4" in tool steels in a pretty big machine. Above that I usually circular interpolate. If I were just using a drill press I'd use a hole saw fursure...
 
I use bi-metal hole saws on cpm 3v without problems. You can get them at Lowes or Home depot. And as I said before since your press is too fast work it by hand and only use short bursts with moderate pressure when operating the press.
 
Nathan the Machinist said:
a vote for the hole saw :thumbup:

I'll drill up to 3/4" in tool steels in a pretty big machine. Above that I usually circular interpolate. If I were just using a drill press I'd use a hole saw fursure...
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Thank you for the input! Always good to see you chime in, been loving the 3V Field Knife! It's started a good few fires now and been through lots of wood.

J. Rosa said:
I use bi-metal hole saws on cpm 3v without problems. You can get them at Lowes or Home depot. And as I said before since your press is too fast work it by hand and only use short bursts with moderate pressure when operating the press.
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Alright I think i'm sold on the hole saws now lol. Just got the new press installed today, she goes as low as 140 and is rated for 3/4" steel so I think i'll take a stab at this later today when I get my chuck installed. I forsee lots of cutting oil :D
 
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