Where to find a sprue plate screw for an older Lyman 4C mold?

[Hellgate]

I have a nice 4 cavity Lyman 358311 158gr RN mold that is my go to bullet for Cowboy Action Shooting. The prior owner of this mold did not loosen the set screw as he removed the sprue plate hinge pin screw and therefore the threads are stripped and the screw loosens as I cast and won't stay snug. I checked with Lyman and they no longer make/stock the screw which is a 3/4" long 1/4" wide with a 24 TPI thread. Nobody seems to make a 1/4" screw with a 24 TPI thread pitch. They are all 20 TPI or much finer. Is there anyone with spare parts to old rusty molds or do I just have to drill out the hole and rethread to a more common screw size? Will a WTB ad here help? I checked McMaster Carr & Granger and a local hardware store with a very wide selection of nuts/bolts/screws and no 24 TPI 1/4" bolts or screws.
Tye in Orygun

[nicholst55]

Give Eric at Hollow Point Mold Service a call. Otherwise, I'd look at a heli-coil insert for a more common thread like 1/4-20 or 28.

[Hellgate]

Pardon my ignorance of machinist knowledge but what is a heli-coil?

[Hellgate]

I just sent Eric an email.

[OldBearHair]

A helicoil is similar to a spring but has threads out side and inside. The inside threads match the screw threads. The outside threads match the tap used to enlarge the worn out threads hole. After the hole is drilled and tapped the " spring like helicoil is screwed into the hole, then the original screw will fit again.

[Hellgate]

I'll look into that if I can find a heli-coil with 24 TPI thread pitch.

[flyingmonkey35]

If you have a tap and die set.

Id Go that route.





Sent from my SM-G960U using Tapatalk

[Hellgate]

Flying monk,
Do you mean drill out the screw hole and re thread it to a larger screw? To me that would be the easiest. I might have to look up a 5/16" tap & die.

[JM7.7x58]

Make your own screw. I’ve had to make screws for my Arisaka. The taps and dies are readily available. I bet you could sell the tools here when you were done with them.

Link to a die nut:
https://www.msdiscounttool.com/catal...CABEgJP-PD_BwE

JM

[MT Gianni]

I'll look into that if I can find a heli-coil with 24 TPI thread pitch.

You want a common pitch such as 1/4 x 20 not an offball.

[jsizemore]

It's been a while but I remember Harleys with a pan or shovelhead used an oddball 1/4 x 24 bolt for the tappet block. There was difference between thru and blind hole lengths. It was easy to get them mixed with other bolts and get a little heavy handed when putting the motor back together.

[swheeler]

Hellgate I think this may be what you need, price isn't bad and spare parts are always welcome.............https://www.midwayusa.com/product/1010249075?pid=894456

[deltaenterprizes]

Hellgate I think this may be what you need, price isn't bad and spare parts are always welcome.............https://www.midwayusa.com/product/1010249075?pid=894456

That is exactly what he needs!

[Hellgate]

OK,
You guys win. The screw on the left doesn't look like the one from my mold but likely will work.The sprue plate alignment/stop screw on the mold jiggles a bit too. I'll just go get the whole kit & kaboodle.
Thanks,
Tye

[swheeler]

I think that is the washer on the screw on left in the picture, hope it gets you up and running like new.

[dbosman]

One, Two, and Four cavity mold rebuild kits.
https://www.midwayusa.com/s?userSear...temsPerPage=48

[Hellgate]

Thanks, guys. Problem solved.