Carbide drill bits through hardened steel?

bodog

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Are there any steels too much for carbide drill bits from Jantz to handle? If I wanted to drill something like 15V at 64 RC or Rex 121 at 70 RC would carbide bits still cut it adequately?

The bit would be run at the recommended speed or very close to it. I would peck at the steel with the bit to keep it from lodging in the steel and breaking.

Would normal light machine or gun oil suffice as the lube?

I'd be working at 800 +/- RPM, which is what they recommend for the bit I'd be using.

Don't wanna waste $35 if it wouldn't work.
 
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I work as a steel/aluminum fabricator and in my experience I go pritty slow when drilling through steel 800rpm seems fast but give it a shot, if you see smoke stop. machine oil/ gun oil should work fine.go for it.
 
I work as a steel/aluminum fabricator and in my experience I go pritty slow when drilling through steel 800rpm seems fast but give it a shot, if you see smoke stop. machine oil/ gun oil should work fine.go for it.

800 RPM is what Jantz recommends using the bit at. Some of the bits are recommended to be used at a considerably faster rate.

I'm more worried about the bit being able to get through some of the hardest and most wear resistant steels on the market right now.
 
The carbide bit will cut it.I would be more concerned about drilling set up. If you don't have a very ridged setup the bit will shatter. Very little runout in your quill and work piece clamped down securely. Feed rate and speed also come into play.
 
I use a very solid drill press and run it at 200 rpm. Keep it oiled and use a mild steel backer to keep from breaking the bit when you punch through.
 
I dunno Jantz, I use Strongarm drillbits. They can drill insanely hard material. 800 rpm is about right for what I done.
Proper cutting oil should be used.

Gun Oil ? I would think not, its gotta be about 75% water. If you have it already at hand, (and I dont think we want to know why you might possess the stuff) you could always try it, but I think Crisco may work better...

Which strongarm bits, the safe crackers? They're significantly cheaper than the straight fluted carbide bits I can find.
 
Just bought these for 17 bucks, half the price of the ones from Jantz:


Material: Solid Carbide

* Sub-Micron C-2 grade premium carbide

* 10% Cobalt content

RHS (Right Hand Spiral)

RHC (Right Hand Cut)

Diameter tolerance (Inches): +0.0000 / -0.0005

MADE IN THE USA


Diameter: 1/4 in.

Diameter (Decimal Inches): 0.25

Length Of Cut: 1-3/8

Overall Length: 2-1/2

2 Flute

Straight Flute

Single End

140 Degree Notched Drill Point

Helix: 15 Degree

Finish: Uncoated
 
Carbide definitely likes to be run faster than steel bits theres plenty of charts and calculators online for speeds. lubricating oil is NOT cutting oil and you will notice a difference but generally anything is better than dry even if all it does is keep things cooler. If you have any flex in your setup get the carbide tipped steel drills they won't break as easily as solid carbide will.
 
Carbide definitely likes to be run faster than steel bits theres plenty of charts and calculators online for speeds. lubricating oil is NOT cutting oil and you will notice a difference but generally anything is better than dry even if all it does is keep things cooler. If you have any flex in your setup get the carbide tipped steel drills they won't break as easily as solid carbide will.

Thanks, I went ahead and bought some cutting oil. Too expensive to break just because I wanted to cheap out on some oil.

I also bought a carbide chucking reamer. I'll probably break that right off the bat.
 
I run carbide Altain drills at 2200 rpm and cut through hardened stainless like butter. I usually use some cutting fluid. It shouldn't be a problem as long as it is a quality bit and I definitely recommend a coated bit. But I'm not an expert just what I do.
 
Guhring makes a quality drill and we use them alot where I work (aerospace machine shop)
They have qood tech support and are accessible

http://www.guhring.com/AboutUs/USACanada/

I have to ask, why do you want to/need to drill through hardened? :)

Because the partial tang blades came hardened and without pin holes. I'm planning on using oily hardwood for handles and don't want to rely on epoxy alone.

The issue is that they're the most wear resistant steels on the market and they're all harder than most steel normally is. Most guidance on carbide drilling I can find only reference hardened steel at something like 50 RC. A lot of these guys are shocked that people work with steels at 60 RC. So 64 through 70 RC isn't really a common thing, I guess.
 
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