Will this drill and tap? Steel tap...

[Makintrax73]

So I'm making a tailstock die holder. I'm right to the point of pressing a 1" socket into the holder. I parted this socket off in my lathe with HSS lathe tools although I scored the chrome with carbide 1st.

I was planning to press the socket in and then drill and tap (Craftsman Kromredge carbon steel) a through hole for a retaining screw (10-24 probably) . I figure on grinding off a hunk of chrome, marking that area and drill there. BUT....will my tap get ruined ? This socket was pretty tough!

Only other way I can see this happen is grind and drill a big clearance hole FIRST then try to line up the tap drill with the clearance hole after I press it in. If I do and don't line it up I am sunk if I do that.

The socket is a .001" press fit.

Thanks!

 

[benmychree]

Hex dies are far from the best to cut threads from scratch, and carbon steel taps are especially not good for stainless steel and hard materials. An investment in quality tools is a good investment ---

 

[Makintrax73]

Hex dies work fine on anything up to and including 12L14, less than 1/2". Been there, done that, got the tshirt.t-shirt.

That's pretty much what I figured on the tap. Clearance hole first it is

 

[Flyinfool]

A 10-32 is a lot stronger of a tap (and screw) than a 10-24, and also is removing a lot less material to reduce cutting forces. 10-32 also holds better.

Are you planning to drill straight toward center or to skim the edge of the socket? If you are planning to skim the edge of the socket I would just drill and press in a roll pin. You can still press the roll pin through if you ever need to get it apart.

 

[Makintrax73]

A 10-32 is a lot stronger of a tap (and screw) than a 10-24, and also is removing a lot less material to reduce cutting forces. 10-32 also holds better.

Are you planning to drill straight toward center or to skim the edge of the socket? If you are planning to skim the edge of the socket I would just drill and press in a roll pin. You can still press the roll pin through if you ever need to get it apart.

I plan to drill through the middle of the socket on one of the flats. The idea being to pin the socket from spinning, and retain the hex die at the same time.

I see your point on the 10-32, thanks. Will look at that.

If I go the clearance hole route and it spins the socket in the tool it could really jam things. Just realized that wrinkle. Although I think a tight press fit should suffice. I could cut some light horizontal slots in the socket, I think it would extrude into the slots and grip better when pressed in.

ETA: My third thought is to clearance hole the socket on one side, and use that for a retaining screw for the die. 180 deg on the other side attempt to drill it for a 1/8" pin. If it breaks the bit or otherwise doesn't work it will have an ugly hole, possibly with a broken drill bit jammed in it, but the tool as a whole will still be useable.

 

[Flyinfool]

You can also use some Loctite retaining compound, #638, on the press fit. A bit of scuff to break the shine of the chrome will help to.

 

[mksj]

Standard carbon steel tap may break going into the socket steel. I did something similar for the vice hex section that my handle sides onto, I just did a press fit with red Loctite. Granted the socket is a bit deeper into my hub but I exert some high force on the handles and I haven't had any issues.

 

[mattthemuppet2]

Here's an off the wall thought. Figure out a way of retaining the socket (loctite, weld, etc), then drill a shallow hole for a magnet at the base of the recess. That'll help secure the die. Make the sliding part that the die holder slides on a little longer than necessary and you can use that to push the die out when you're done. I reckon that'll be pretty slick.

 

[Makintrax73]

Update: Project turned out fine. I pre drilled the socket. Good thing I did, could've never tapped it. I did not pin the socket. It seemed to press in quite solid and I used locktite. Don't think it will go anywhere you can only put so much torque on a 4" long 3/8 handle.

This tool needs some rounded knurled knobs on the handles, and some polish, but it turns 3/8-16 in raw 12L14 with ease.....




I'm also considering mounting the arbor permanently in a MT2 sleeve. Project for another day.

Thanks again guys for the help and advice.

 

[rwm]

...or turn a new arbor with an integral M2 taper. Nice show. This will work well.