براغي رأس كبس مقاس #4-40 × 5/8 بوصة | محرك سداسي | رقعة نايلون | ملولبة بالكامل | فولاذ سبائكي مع أسود حراري (300/عبوة)

The black oxide finish on these looks sharp and holds up well in my tooling setup. The nylon patch keeps them snug without needing thread locker, and the 300-count box is a solid value for small precision assemblies.

I’m building a fixture and these #4-40s came out of the box perfectly threaded, the black oxide finish looks great under the shop light. The 5/8" length fit my jig plate flush with the nylon patch gripping tight on the third re-tighten.

The nylon patch on these screws holds tight even after a few removals, which is perfect for my precision assembly work. They drive cleanly with a hex key and the black oxide finish looks great against the aluminum parts I’m using them on.