1/4-20 X 5/16" 尼龍粒杯頭內六角止付螺絲 | 合金鋼 (100 個/包)

The nylon pellet cup point really grips the work surface without chewing it up, so these set screws hold snug even on softer materials. They fit a standard hex key with no slop, which made positioning them in a cramped bracket far less frustrating than I expected.

The hex socket drive makes these easy to torque down even in cramped spots, and the nylon pellet grips firmly without marring surfaces. I used a dozen for a jig build, and every one seated perfectly at first try.

Finally found set screws with a nylon pellet that actually stay put during adjustment. The hex socket drive makes it easy to get them snug in tight spots without stripping.