Shallow Taper Screw Head Id?

[pebbleworm]

I am taking apart an old vise and found these shallow taper allen screws holding the remaining jaw. I think I have seen these before in an old book on fasteners, but have not been able to find them on the interwebs. If anyone knows what they are called I would sure like to know. Taper seems to be about 25-30 degrees. It's not critical to making a replacement jaw, but I can see some advantages over a 90 degree countersink. Thanks in advance!

 

[4GSR]

Looks like insert screws used on face mills to secure the inserts. What thread are they?

Edit: Insert screws have Torx sockets instead of hex sockets, but would probably work depending on the thread size. If not, modify some flat head screws.

 

[pebbleworm]

Thanks for the fast reponse! Threads are 1/4X20. The remaining jaw is not hardened so it and these could (and I'm leaning towards probably) be shop made since it came out of a big installation. I am thinking of facing the jaws with some 1/4" copper so some taper on both pieces could help. I think.

 

[4GSR]

Thanks for the fast reponse! Threads are 1/4X20. ....snip.....

They definitely are not insert screws. I would change the countersink to something easier to obtain, like a 82 deg. countersink. That way you can use standard flat head screws.

 

[pebbleworm]

That's what I am thinking- it won't make much difference once everything is back together. What I think is the build date on the vise is September, 1943 so it's been around a while. I was just curious about these oddball screws. The soft jaw is stamped with the model number of the vise, so it must be from the (Rock Island) factory.

 

[royesses]

I needed 4 of those about 6 months ago. Metric. I never found the name of them. Sears has them listed as spare parts for the 6 inch vise. I found some thick button head screws at Ace hardware. I turned down the heads and tapered the top to match the old screws. A bit shallow on the hex socket, but they are still holding the vise jaws on. I'd like to know the engineering name of them.