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Posted: 11/6/2016 4:05:03 PM EDT
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I've been tinkering with some custom KeyMod stuff and found myself needing screws (Bravo Company seems to be a good source of nuts).
VLTOR picked some strange screws when they designed KeyMod. First off they picked a 100-degree flat head screw design vs. the much more common 82-degree. Then they only left 0.330" of room in the rail for the screw head. The vast majority of #8-32tpi screws have 0.359" diameter heads (and an Allen, T20 or IP20). 0.312" is also a less common standard that can be found with a T15 head but is more common with a Phillips which is a poor choice for a reusable application. Some non-spec KeyMod rails only have room for a 0.300" head. I've searched a lot of vendors. Most don't give head diameter. Ironically Amazon seems to have minimum orders of 3,000-8,000 or so for flat head 8-32 machine screws. Here are the closest I could find: Low strength zinc plated steel T15 0.312" 82-deg flat head. 1/2" length https://www.mcmaster.com/#90920A194 <-- These are what I ordered. About $10 for 100. Stainless steel IP15 0.312" 82-deg flat head 3/8" length https://www.mcmaster.com/#92703A304 Stainless steel IP15 0.312" 82-deg flat head 1/2" length https://www.mcmaster.com/#92703A307 The only 100-degree 8-32 flat head with a head diameter under 0.330" that McMaster Carr lists is a Phillips head: https://www.mcmaster.com/#90471A260 / https://www.mcmaster.com/#90471A270 I suspect the use of a 82 degree screw in a 100 degree hole will not be a big issue. It will decrease the bearing surface and primarily hold on the lower part of the hole. Mike |
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