Hi everyone --

I have an older black Weller 140/100 soldering gun (with a light bulb -- not sure of the exact model number. The gun itself has a red tag that says "Weller Universal 140/100").

I'm unable to fully tighten one of the recessed hex screws that's supposed to hold the tip in place. I googled high and low for the size/thread pitch so I could buy a replacement, but I couldn't find anything specific, only various links to what appears to be a discontinued collar/hex screw/allen wrench combination --

https://www.tequipment.net/Weller/D550HEXCOL/Soldering-Accessories/?OrderItemId=7716952

I'm pretty sure if I place an order they'll just say it's out of stock & cancel it (and even if it shipped, it'd be $15 essentially just for a screw).

If anyone knows what the diameter/thread pitch is so I could buy a replacement locally, I'd love to know.

 

Well, You won't be installing a new one without removing the old one,
so remove the old one and take it to your local Hardware-Store so You can match the Threads.

I would suggest getting a Stainless-Steel Hex-Head-Bolt, instead of a Set-Screw,
it will last much longer, and will be easier to tighten.

Don't over-tighten it, just snug it down enough so that it won't get loose and fall out.
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Mine is #10/32 What i did is replace the screw with a Allen-hex recessed grub screw.
If the collar thread is stripped, just drill and tap the collar on the opposite side.

 

Mine is #10/32 What i did is replace the screw with a Allen-hex recessed grub screw.
If the collar thread is stripped, just drill and tap the collar on the opposite side.


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Thank you! This is exactly the info I was struggling to find. I guessed it might be #10-24, so thank you for clearing that up.

I think the threads are fine, it's the recessed part that's giving me grief -- the wrench doesn't grip as well anymore when I try to tighten it all the way down. Do you remember what the length of the screw is off the top of your head? If not, no big deal -- I can just take one out tomorrow and measure it myself.

 

Thank you! This is exactly the info I was struggling to find. I guessed it might be #10-24, so thank you for clearing that up.

I think the threads are fine, it's the recessed part that's giving me grief -- the wrench doesn't grip as well anymore when I try to tighten it all the way down. Do you remember what the length of the screw is off the top of your head? If not, no big deal -- I can just take one out tomorrow and measure it myself.

The length of the grub screw is such that when tightened, the top is flush with the outside of the collar. #10-32 BTW.

 

The length of the grub screw is such that when tightened, the top is flush with the outside of the collar. #10-32 BTW.

Yes, it is #10-32 -- I should have clarified in my earlier post that I incorrectly guessed it was #10-24.