need a 5/8-12 RH Acme tap

[JoeCB]

Straight sides, round top? sounds like some Chinese roll formed thread. Feeling lucky? look for a big "C" clamp with that correct size screw, cut off the "nut" , machine round and use as a weld bushing.

Joe B

[754]

I suggested single point, and have done it for 1/2. Or smaller entry hole, and made my own tool to cut it.
A bit less work than making four or five taps in my opinion..
Light cuts of course.. V thread it first to near final width..makes it easier.

[larry_g]

https://www.protoindustrial.com/en/s...p.823-856).pdf

Looking in the Proto catalog above you will find a few items that screw onto the 5/8-12 acme slide hammers, like in the link below;


http://www.toolup.com/Proto-J4206CA-...SARM-6-TON-2-W

http://www.toolup.com/Proto-J4256S-2...nside-Hook-Jaw

Is it possible to buy one of the screw-on adapters like above and modify it? It's a lot cheaper than buying a tap, if you find one.

lg
no neat sig line

[metalmagpie]

Straight sides, round top? sounds like some Chinese roll formed thread. Feeling lucky? look for a big "C" clamp with that correct size screw, cut off the "nut" , machine round and use as a weld bushing.

Joe B

The thread is from a slide hammer which is part of a Proto puller set which costs several hundred dollars. It isn't Chinese roll formed thread, that's for SURE.

metalmagpie

[metalmagpie]

https://www.protoindustrial.com/en/s...p.823-856).pdf

Looking in the Proto catalog above you will find a few items that screw onto the 5/8-12 acme slide hammers, like in the link below;


http://www.toolup.com/Proto-J4206CA-...SARM-6-TON-2-W

http://www.toolup.com/Proto-J4256S-2...nside-Hook-Jaw

Is it possible to buy one of the screw-on adapters like above and modify it? It's a lot cheaper than buying a tap, if you find one.

lg
no neat sig line

This project (adapting a slide hammer to Vise-Grips) doesn't justify anything like that. I have already made an adapter with 1/2-13 female threads. I have a 1/2" bolt about 18" long and I'll weld some kind of blob on it and drill a clearance hole down some kind of weight when I actually need it.

metalmagpie

[metalmagpie]

Just a followup note in case someone is searching this forum for this issue. I took the Proto screw to my buddy's house and we looked at it on his optical comparator. It turned out to be a 60 degree thread but with the tip ground off the turning tool so that the thread had flats on both the crest and 'valley'. See:



So there isn't anything all that unusual about the thread. It appears quite possible to single point it. The proprietary nature probably comes more from the 12TPI than from the thread form.

metalmagpie