How Des One Drill A Hole...

USN_Airdale

in hardend steel/S.S. ?
i have one 1/8" carbide bit, the exact size i need to the hole to be.

would heating the object and let cool (annealing) be of any help ?

MIKE WISKEY

"would heating the object and let cool (annealing) be of any help ?"...............yes BUT..........if it is hardened steel you will 'soften' it. what are you in need of drilling?

mrbruce

Seems like a carbide drill would be able to drill most steel with out a problem..

charliemeyer007

Way back in the day drilling a Savage 99 or a Springfield receiver was done with a special pure cobalt drill bit and jig with a hardened pilot. The bit was turned at high speed with steady moderate down pressure.

Boeing tap lube was the best I ever used.

I would consider paying to have it done by EDM.

added carbide bits - slow speed, oil/coolent, moderate pressure and a rigid set up preferred.
http://www.wlfuller.com/html/drills_for_hardened_steel.html

Fluke design looks just like the pure cobalt bits I used.

MG1890

Regardless of being a gun or something else, the cutting tool needs to be harder than the material. If you really have a carbide drill (these are hard to get, and are used nearly exclusively in production machining), it is plenty hard enough without trying to spot anneal the gun.

Even fairly hard steel can be drilled with a quality high speed steel drill. It is important to have a rigid setup and proper cutting fluid.

Except for case hardening, I can't think of a firearms application where the material is through hardened to the point a good HSS drill won't cut it, especially if presented on a Bridgeport mill or similar.

The comment about Stainless Steel being easy to machine: This only applies to the 400 series materials commonly used in firearms. 300 series stainless, along with the high temperature alloys that share similar chemistry to stainless, can be and typically are miserable to machine! 416R as used in rifle barrels does machine beautifully, though!

XXCross

Only one drill ?
send me an address and I
ll send ya a hand full.

Cheechako

You mentioned SS which is not hard. One of the nice things about stainless is it's machinability.

If the thing you are attempting to drill is case hardened rather hard all the way through, you only need to get through the case and then use a standard drill.

If you've never used carbide drills, it may be a good idea to have someone else do it. Carbide is very hard and it only takes one little slip for the drill to shatter.

JMHO

Ray

XXCross

Cheechako
Someone needs to take a second look at the machineability of
SS. PH hardening stainless can get very hard. If it is allowed
to pass through the 900 degree transformation range slowly it
is just about like glass. Trying to drill some stainless with
a dull drill is only going to make the problem worse.

Cheechako

XXCross

A valid point. But, since this forum is mostly about guns and shooting I just assumed the SS he was mentioning was one of the common types used in firearms, particularly barrels. But, sometimes I assume too much, too fast.[:I]

Ray

USN_Airdale

quote:Originally posted by XXCross

Only one drill ?
send me an address and I
ll send ya a hand full.


Carbide bits ?

i worked in a machine shop for a year, the QC department insisted we change drill bits every 10 pieces of what ever we were working at the time, therefore i have every fractional, numbered and lettered drill bits of standard bits, in fact i might have triple of most and some like the #30, #21, and 1/8th" i probably have a dozen of them. thank you Sir for the offer, but i really do not need any other than a few selected Carbide bits.

discusdad

old timers cutting fluid for extremely hard material drilling. use turpentine! slow speed constant down pressure, never let the drill float in contact with the work. I learned this in my 1st machine shop that had lots of WW2 era machinists nearing retirement.

USN_Airdale

for all you fine folks, first of all, i had a major mishap with a special made piston LWRC, .499LWR, the timing or dwell was not done right, the lugs of the bolt were partly gouged off, the lugs in the barrel extension were also ripped off, LWRC said they could not fix it because all the .499LWR parts were dumped or sold off, any way, i studied the carrier and key, for a few weeks, took measurements the key was my big concern i presumed it was hardened due to the rounded dimple in the face of the key where the op-rod struck it, i went to my shop this morning set it up in my drill press vise, what the hell i told myself, try one of the standard drill bits and try drilling a pilot hole first, much to my surprise it cut very nicely, drilled that hole to the depth needed, then drilled the hole to fit the gas tube, next, the angled hole for the gas to enter the carrier where the gas impinged into the bolt, this is going to be a * i thought, drilled a small pilot hole in the horizontal position, then set it up for the angle, once more i could not believe things were going my way, got that done an breathed a sigh of relief, the piston key BTW is dovetailed into the carrier, after a short break i started on the carrier, drilled that hole for the gas to enter the bolt, that too was a breeze, next the two angled holes in the side of the carrier for the gas to escape, i knew it, there had to be a fly in the pie, try as i may i burned up three drill bits and barely made a mark, then a flash bulb went off in my head, so into the reloading room where my other "stuff" hangs out, out come the Dremmel and several carbide dental drill bits, got the angle set up and zippppppo i got the two holes drilled but they are too small so tomorrow i'll go back to the shop, set it up for drilling the holes to the proper size, hopefully the pilot holes will allow drilling with a standard bit, i'll let you all know tomorrow how it worked out.

basically what i am doing is converting the piston BCG to a gas BCG, preliminary fitting everything is lining up about 99.7%

later guys. [:D]