Drilling HSS

[Johnm1]

I'm in the process of fabricating a new hand for a Marlin 1873 tip up revolver. The material I chose was a bit from a lathe and is made of high speed Steel. It was the correct thickness. Shaping it isn't a problem. I realize there's going to be a lot of trial and error to make it work, but the shape is fairly simple. The problem I'm having is drilling a 5/64th inch hole in the high-speed Steel. I have wasted two Cobalt drill bits and when I was done doing that the dimple I created using the center punch appears unchanged. My drill press is not very good, but should do for a straight simple hole like this. I have it set as low of a speed as possible. I'm pretty sure that is 700 RPM. I am using Cobalt drill bits and I am providing a continuous flow of oil over the bit and the piece being drilled.



I'm open for any suggestions on how to drill a simple hole.

 

[DT Guy]

Straight-up carbide bit or anneal and reharden will likely be your only choices.

Larry

 

[Johnm1]

Straight-up carbide bit or anneal and reharden will likely be your only choices.

Larry

Thanks. I'll try to anneal it first. Save that I'll hunt for a carbide bit. Not sure ill find that at my Ace Hardware.

I noticed in my picture that there were two starts from the bits not in the center punch divot. My drill press kinda gets me in the general vacinity and that's about it. If I press too hard I can see the bit walk.

 

[JohnKSa]

How hard is the cylinder ratchet that the hand will bear on? I think I would want to make the easiest part to replace out of softer metal than the part that is hard to replace.

 

[Johnm1]

How hard is the cylinder ratchet that the hand will bear on? I think I would want to make the easiest part to replace out of softer metal than the part that is hard to replace.

Very good point. It's not like I'm going to put 10,000 rounds through this revolver.

 

[Show Me]

Thanks. I'll try to anneal it first. Save that I'll hunt for a carbide bit. Not sure ill find that at my Ace Hardware.

I noticed in my picture that there were two starts from the bits not in the center punch divot. My drill press kinda gets me in the general vacinity and that's about it. If I press too hard I can see the bit walk.

Beaver tool and drill
If the thin bit is walking then center punch is a mark not a dimple. Drill a hole in a lath bit. One fella here tried to weld a 1 1/2 inch hammer drill bit back together. I said , come on man.

 

[Johnm1]

Beaver tool and drill
If the thin bit is walking then center punch is a mark not a dimple. Drill a hole in a lath bit. One fella here tried to weld a 1 1/2 inch hammer drill bit back together. I said , come on man.

I think @JohnKSa had a wise suggestion to make the hand out of softer material. Replacing a hand if it wears out is simpler than reparing the ratchet teeth/cylinder if the hand is harder than the ratchet teeth and causes damage.

 

[Show Me]

I think @JohnKSa had a wise suggestion to make the hand out of softer material. Replacing a hand if it wears out is simpler than reparing the ratchet teeth/cylinder if the hand is harder than the ratchet teeth and causes damage.

Kinda stupid to say but I use cheep brake pads at the shop so I don't necessarily half to change rotors on the company light trucks and cars. Best I can do this early