Pin Punches - Good Steel for Them

Most of the time pin punches do their job and pins push or are drive out
with modest effort. Once in a while you really have to wail on them to
get them started moving. When that happens the average pin punch just
folds like a cheap suit.
With this in mind I've been thinking about making some for special
applications. Use my regular el-cheapos formost normal applications,
but break out my "special ones" when the pin needs a little more push.
So, what would be a good choice for the application? W1 drill rod?
4140? I have those on hand, although either would require heat
treating, and the drill rod would probably require heat treat and
tempering. Is something else better?
Reply to
Bob La Londe
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What do you mean they "fold"? Do you mean they bend?
Good ones are made of good tool steel. I never had one "fold." Do you know what brand they are?
The traditional tool steel for "pounding" is S6. It's moderately strong and bend-resistant. It's big thing is that it's shock-resistant.
The best combinations of strength and shock resistance are proprietary grades of vanadium tool steel. But it's unlikely they'll be much more resistant to bending than any good-quality pin punch.
The properties of W1 depend on how you heat-treat it. It is NOT an alloy steel. Basically, it's a good grade of plain high-carbon steel.
4140 is similar to S6, except that is has a little bit lower alloy components and no vanadium. S6 contains 0.2 - 0.4% vanadium.
Reply to
Ed Huntress
S6 sounded interesting. I tried to look it up at my usual sources, but didn't find it. One source has S5 and S7 and another just has S7. S7 actually looks very promising, but of course I have no experience with it.
Reply to
Bob La Londe
That whole S-series (for "shock") is a graduated series of alloys. S5 or S7 ought to be as good for pin punches. The fine discriminations come into play in tools that do repeated pounding, generally under power.
Here's a good rundown on S5:
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You can look them up on MatWeb to see the differences -- I think.
Good luck!
Reply to
Ed Huntress
Do not know about better, but I make pin punches out of exhaust valves. An d just turn them using carbide inserts. So no heat treating required. Hav ing the pin part as big in diameter as possible helps as does having the pi n part as short as possible. I get exhaust valves from places that do auto motive machining.
Dan
Reply to
dcaster
The long parallel drive punches will never hold up to heavy hammering. They are not really designed to, they are designed to push the pin the rest of the way through the hole. To start one, you should use a tapered punch with a tip small enough to push the pin just past the surface. Once the pin's grip has been broken, then you use the drive punch.
I use nail sets, 'cause they're cheap and readily available.
Paul K. Dickman
Reply to
Paul K. Dickman
Just make sure you don't try this with a sodium filled valve. -Gene
Twenty years from now you will be more disppointed by the things that you didn't do than by the ones you did do.
So, throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover. - Mark Twain
1987 23' Grady-White Gulfstream 2004 17' G3 CC 1756
Out of Shallotte, NC
Reply to
The Last Boater on USENET
For my last intractable in problem -- wheel on a TroyBilt tiller -- I cut the shank off an unrecoverable SnapOn phillips screw driver, drilled a matching hole in the end of a 3/4" sq m/s rod, wedged the screw driver shank into the hole. Application of a 5# hammer removed the frozen-in pin. And the punch remains in good shape, too.
Reply to
Mike Spencer

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