Lee left hand threaded sprue plate screw problem

[Shuz]

The former owner of a Lee 309-113LH mould let the sprue plate work loose. When I acquired this mould, I attempted to tighten the sprue plate screw but it wouldn't tighten. I contacted Lee and they informed me that this mould has left hand 10-24tpi threads. I guess I succeeded in buggering the hole enuf that now that the left hand 10-24 screw won't enter and tighten. What's the best remedy for this screw up?

[runfiverun]

drill and tap.
then drill and tap the side for a set screw.

[Shuz]

What size should I go to?

[Maven]

Ray, You've nothing to lose by using 10-24 tip since you're going to hold that sprue plate screw in place with a set screw anyway (8-32 works for me). You can always go larger if 10-24 doesn't work.

[Tackleberry41]

I have not really seen where going from right to left threads fixed anything. So now it comes loose opening vs closing.

As for a screw, the next step up, or maybe something metric since they tend to be in the middle. It really does not need a ton of tension.

[sundog]

I had one go south on me, too. I drilled a hole ALL the way through the diameter of the hole in the sprue plate and put a bolt and castle nut on it. Works fine but will not sit flat on its bottom, but who cares. All the work is done while it's being held.

[country gent]

If the 0-24 left hand threds are gone then a theres nothing there for any #10 thread. A number 12 thread will be needed or 1/4" If theres room Id go 1/4 28 and open the sprue plate hole to 1/4". The locking set screw is a good idea but opening the hole up may not leave enough wall thickness for it. Another way to go is to drill and tap for 5/16 x 18 and lock tite the plug in place work this flat with top of mould and then drill and tap back to 10x24 or 10x32 threads. this allows the sprue to remain original and the set screw to be installed. Use a standard cold rolled bolt run in to bottomed tight with locktite. Cut bolt off close with a saw and file down to match top of blocks. Center mark the stud nad drill and tap to 10-24 or 10-32 threads. Use an button head allen bolt and belleville washer to tension the sprue plate. the set screw to lock it in place. The mould can be fixed easily with a little time and materials. Use red or green loctite to help lock the stud in place.

[Shuz]

I had one go south on me, too. I drilled a hole ALL the way through the diameter of the hole in the sprue plate and put a bolt and castle nut on it. Works fine but will not sit flat on its bottom, but who cares. All the work is done while it's being held.

Corky--This mould is one of the new designs that looks like it was made to fit a 1" mould guide for a furnace. As I look down the hole on the left side of the block, I can see part of the handle that would also have to be hogged out or the bolt would not pass thru. Did you run into the same issue? I like the bolt and castle nut solution because it eliminates the need for drilling another hole and set screw. Besides I only have a few taps left to me by my Ohpa and they are of some questionable value.

[Shuz]

Ray, You've nothing to lose by using 10-24 tip since you're going to hold that sprue plate screw in place with a set screw anyway (8-32 works for me). You can always go larger if 10-24 doesn't work.

Paul--There is absolutely no threads left. I either have to tap larger or use Corky's solution of drilling all the way thru and putting a nut on the bottom. By the way, I found an old tap that was my Ohpa's that is a 14 by 20. That measures about .243" in diameter. Only .007 from 1/4"! Is a number 14 bolt common? Anyhow, that taps shank fits thru the sprue plate nicely, so that would be an option also if I can locate a #14 screw!

[Safeshot]

You might want to try a 6.5 mm or 7mm (Metric) bolt or machine screw. A self-taping one might be helpful.

[MT Chambers]

With the few remaining Lee molds that I have, I drilled right through and used a nut on the bottom as someone else suggested. The problem is that the screw used by the factory will pull the threads right out of the soft aluminum, even if you have never turned that screw.

[Traffer]

I have never done this but it should be possible and if so, It will be a (better than original) fix. This kind of fix is used on securing much stronger, higher torque head bolts on split case automobile engines (VW aircooled).
I used to work in a shop that built monster VW engines and this was part of the kit and a must if you went from 80mm jugs with low compression to 96mm jugs with high compression. The head bolts on these things are a standard 8 mm into aluminum. When the bigger jugs are put on the head bolts pull out of the aluminum like pulling out of bubble gum. So they use inserts. Drill out the 8mm hole to the proper size to put a 20mm steel insert in there with very coarse threads. With all that surface area they do not pull out. The inside of the inserts are the standard 8MM.
A long winded explanation for .....inserts. Drill out the hole to the insert size and run the insert in and then the proper bolt or screw and ...better than original. You probably wont find an insert that will have the proper left hand thread for a stock factory screw but just go with a standard right hand thread of the same diameter. It is a bit more expensive and maybe more labor but then you have a very very good job. Here is a link but most hardware stores and probably Home Depot and Auto Parts stores should have a good supply of these. Also search thread inserts on eBay and get a very wide range of types and prices.
https://www.zoro.com/e-z-lok-thread-...g&gclsrc=aw.ds

[Shuz]

I fixed my mold with a larger self tapping screw. It was real easy to do and seems to work fine, altho I haven't cast with it yet! Too many moulds and too little time!

[robg]

A self tapping screw is easy ,if that fails the a thread insert will work well.

[Tackleberry41]

Guess just another reason to not give Lee money on molds anymore. I have at least 1 lee with the lefty threads, have never touched the screw, but it came loose and wont tighten. A brand new mold, normally I wont buy Lee anymore, but a cheap .575 RB mold for experimenting. It barely survived the first casting session, maybe 10 casts. The sprue plate screw is messed up, and cutting the sprue has mangled the mold, denting it where the aluminum is thin.

[MT Gianni]

Paul--There is absolutely no threads left. I either have to tap larger or use Corky's solution of drilling all the way thru and putting a nut on the bottom. By the way, I found an old tap that was my Ohpa's that is a 14 by 20. That measures about .243" in diameter. Only .007 from 1/4"! Is a number 14 bolt common? Anyhow, that taps shank fits thru the sprue plate nicely, so that would be an option also if I can locate a #14 screw!

Old thread and I hope it is fixed but I believe that is a 1/4" x 20 threads per inch tap.

[MT Chambers]

That screw will pull out the thread regardless of which way it is threaded, other mold manufacturers don't seem to have this problem with normal threaded screws and a set screw, it may be that the alum. is too soft.

[country gent]

There is a 12 X28 and a 14 X20 number threads taps also. WOrking in a small shop I needed a new 1/4 20 tap for a touchy job and ran to the tool supply store quick wasnt paying attention and grabbed a 14 20 tap by accident. The problem may be how close the hole is to the 2 edges having enough left to support the insert or new threads with out breaking out the sides.

[PHyrbird]

Ladies & Gents: I disagree. This is not a issue that we have to fix. This is a LEE design problem Anyone with any machine tool knowledge can tell you most aluminum needs at least 1.5-3 diameters for threads to hold. WE should NOT need to install a set screw that should come from the factory. Thread locker is not a solution because casting temps exceed the release temps of all compounds. I personally like most of my Lee products, even almost all the molds. I have NO sympathy for shoddy design or quality problems because they are not following Richard Lee's concept. Working inexpensive innovative high quality tools. They sell a lot of equipment.
I enough of us rattle their cage they will improve. They have already demonstrated the need to listen to customers.
So