براغي غطاء بمقبس HOLO-KROME 77482 1/4-28 × 4" | محرك سداسي مقبس | فولاذ سبائكي أكسيد أسود حراري (100/عبوة)

The black oxide finish feels tough and consistent across all 100 pieces, and the socket drive seated my Allen key without any wobble. I used them to hold a fixture plate on my mill, and every single one threaded home cleanly at full depth.

These 4-inch screws threaded perfectly into my jig fixture without any binding. The hex drive holds the driver bit firmly, making assembly work much easier.

The thermal black oxide finish is a nice touch for resisting rust in the shop, and the hex socket drive makes tightening them in tight jig spaces much easier than a hex head. I used a dozen on a new drill press table and they seated perfectly with no wobble.