10-32 Socket Cap Screws that are partially threaded (to ride in a picatinny slot)?

[agent_mango]

I find that some inexpensive but decent accessories designed for picatinny rails come with fully threaded 10-32 screws as the crossbolt, which is disappointing because they can mark the top of the rail when tightened.

Would partially threaded screws avoid this problem? Where can I find screws (socket cap and button socket cap, high grade steel, black oxide) that have an unthreaded portion of say 7/8"? (If that means starting out with a longer screw, I can still shorten it to length.) McMaster Carr lists partially threaded screws, but in the schematic for those it always says may be partially or fully threaded. I'm thinking of checking out a Bolts Plus location tomorrow.

Or would a decent option be to turn the central part of a fully threaded screw down to 0.150"?


Thank you for your thoughts!

 

[dogzilla]

Brofasco will sell you 1 screw or a hundred over the counter. Take the mount in with you and pick the length of screw that best suits you

 

[agent_mango]

Here's what I ended up doing. I found some 10-32 socket head alloy screws with an unthreaded portion of 3/4". I would've preferred 1" of unthreaded, but there was a way to remove the offending threads.

Used rubber bands to hold the drill's trigger at lowest speed, then used a dremel to grind down the bit of threads close to the end but still ending up in the picatinny slot.



Also ground down some #10 washers (in a somewhat analogous method) to go with it. Top is the original button head screw that came with the BUIS.



This cold blue is quite convenient to use.



Looking good.