Drilling hardened Ball Pein Hammer

[JRT]

I'm trying to drill a 3/8" by about 1/4" deep hole in the tip of the pein side of a hammer with a titanium bit and it doesn't even leave a mark. I'm running my Rockwell mill as slow as it will go at 370 RPM. Possibly I accidentally work hardened it when trying with a standard drill bit before I bought the titanium one? I'm just at a loss, don't know what to do. Carbide bit possibly? Anneal the tip of that hammer? I want to put a tungsten carbide "ball" in the hole and use it to straighten warped knife blades. Thanks in advance!

 

[markba633csi]

Carbide bit would work- or, what about making a new hammer head from mild steel and installing the ball in that?

 

[MrWhoopee]

Those "titanium" bits are just HSS coated with titanium nitride. They may wear better than plain HSS, but that's about it. You will need carbide for what you are trying to do.

 

[RJSakowski]

Those "titanium" bits are just HSS coated with titanium nitride. They may wear better than plain HSS, but that's about it. You will need carbide for what you are trying to do.

And for some of the cheaper bits, the coating is simply cosmetic with no significant mechanical properties.

 

[francist]

It’s possible the head is only case hardened in which case (heh heh) if you grind a flat on the end where you’re going to put the new hole anyway you may get through the hardened outside layer into a softer core. I know I’ve tried to “save” badly chipped hammers by reshaping the heads and ran into that. Don’t know if it was just peculiar to the one or two I have but it may be worth a try.

 

[markba633csi]

Get a cheaper import hammer- the one you are trying to use is too good

 

[whitmore]

I'm trying to drill a 3/8" by about 1/4" deep hole in the tip of the pein side of a hammer with a titanium bit and it doesn't even leave a mark.

Yeah, the steel bit under the TiN coating isn't much stiffer than the hardened parts of a hammer (and peen faces
are always work-hardened)

don't know what to do. Carbide bit possibly? Anneal the tip of that hammer? I want to put a tungsten carbide "ball" in the hole and use it to straighten warped knife blades. Thanks in advance!

Annealing would be possible, but ultrasound (impact grinding) or EDM would be preferable.
For lab work, we made anvil faces from rods (cylinder/RNG coin-shaped) tungsten carbide.
That was decades ago, Carbolloy-999 shrink-fit into a heavy steel collar. It worked great; not
clear that a ball in a drilled hole has as much support, though.

I think the steel was machined with a ramped 'lead-in' to the socket, fitted with the insert
while hot, and the steel machined down to make it flush to the carbide.

 

[akjeff]

Carbide drill or end mill. Or, if you have access to a TIG welder, light up on it for a bit and spot anneal it.

 

[cathead]

I made a hammer with a ball bearing out of a race and have not been able to damage it. I question whether
a carbide ball is really needed.

 

[RaisedByWolves]

Those "titanium" bits are just HSS coated with titanium nitride. They may wear better than plain HSS, but that's about it. You will need carbide for what you are trying to do.

And for some of the cheaper bits, the coating is simply cosmetic with no significant mechanical properties.

I've never seen any improvement in using these other than how much lighter my wallet is.

A Cobalt drill is a much better purchase over these for not much more in price.