Screws for 1911 Optic Mount

[RippinSVT]

Guys, what size machine screws (beveled head, Torx) would I use for a standard type 1911 optic mount? My Bianchi Open gun is missing a few on the shroud. They are Torx and short (I'll measure, I'd guess 3/8" long). I don't have the stuff to measure thread pitch, however some research indicates a 5-40 thread is pretty standard. Does this sound correct and common?

Thanks,

Kyle

[zzt]

You have to know the size and thread pitch. Unless you were a machinist or something similar, you won't be able to tell by looking. Bring one of the screws or the mount to a local hardware store and see what fits. All the ones near me have nuts glued to a board. Try your screw in some of them to see what fits. If you bring the mount, ask for help, or try them yourself. The trays are clearly labeled. BTW, your threads may be Metric. You can find that out there also.

[rishii]

Your local hardware store may or may not carry them

At least none around here do

Most do use 5-40, weigend uses 6-40

I have an old Dillon stamped steel flat wrench that I drilled and tapped with with various thread patterns including 5-40, 6-40 that I use to compare threads, and it's a time saver when it's time to cut screws to length

I just screw them in, measure with a caliper and cut to length

[RippinSVT]

Thanks guys. I'll see what I can do. Good thoughts.

[Dan Sierpina]

If the other screws are .125 it's a 5-40. if they are closer to .136 they are 6-40. That is the outside diameter of the thread. You may have a tougher time finding Torx than hex socket screws.

[RippinSVT]

If the other screws are .125 it's a 5-40. if they are closer to .136 they are 6-40. That is the outside diameter of the thread. You may have a tougher time finding Torx than hex socket screws.

Thank you Dan, that's a good starting point.

[kimberacp]

I just bought a screw gauge from Ebay with three holes to check 5-40 6-40 or 8-40, I think, I forgot at the moment. A few dollars, thought I would it a try.

Also, Ebay has the screws your looking for. Check they have all type. You just have to become familiar with screws threads and pitch and all that stuff.

good luck

[zzt]

If your #6 screw starts but will not thread in, it is 6-48.