Lyman mold with stripped threads.

[Kylongrifle32]

Anyone here repair stripped threads or know where to send a mold to have repair done?
I picked up a lyman 4 cavity .356 mold several months back from an auction site. It has been sitting on the shelf until last Saturday when I finally got it out to do some casting with it. After about six pours when I went to hit the sprue plate it went flying off. The threads were stripped out on the hold down screw and it was only held in place by the set screw. Now I have a mold that is in need or repair.

[dale2242]

I have used a device they call a Helicoil to repair stripped threads.
I`m not sure they make them for screws that small.
It would be worth a try.
It looks like a spring and goes in the hole to replace stripped threads.

[bob15]

If the threads are a "regular" machine screw thread, you can probably put a time-sert or key-sert thread insert in it. You can do it yourself or take it to a machine shop and have them repair it.

[Kylongrifle32]

I wasn't sure about the hardness of the steel the mold was made of. And how hard it would be to drill and tap.

[jim147]

Looks like Keensert sizes start at 10-24. I'm not where I can check what size that screw is.

[beshears]

Try a longer screw first

[Kylongrifle32]

Thanks for the replies and ideas. I guess I just had a brain fart when the sprue plate went flying. Sitting here now thinking about it I can just move the sprue plate mounting hole over to the stopped screw hole. Turn the set up 180 degrees around and put the stop post in the stripped hole.

[MT Gianni]

I bought a 4 cavity mold in the early 90's that had a stripped sprue plate screw hole. I went with 1/4 20, the next size larger tap and the easiest screw in the US to find. The original is still on there.

[Catshooter]

If I recall, that is a 12x28 thread. Not really common, but still avalable. MT Gianni is correct: 1/4x20 is the next size up. If I was going to go the 1/4 inch route I'd be tempted to do 1/4x28. A fine thread is better at holding than a coarse, which is why Lyman used what they did.


Cat