براغي ذات رأس أسطواني 5/16-18 × 3 بوصة | محرك سداسي | حبيبات نايلون | خيط جزئي | فولاذ سبائكي مع أكسيد أسود حراري (100 / عبوة)

Used a few of these to replace worn bolts on a milling machine fixture, and the nylon pellet locking feature keeps them from vibrating loose even under heavy cutting loads. The black oxide finish slides into tapped holes smoothly without galling. Exactly what I needed for tooling repairs.

Grabbed these for a jig I’m building, and the hex socket drive fits my wrenches perfectly. The black oxide finish seems tough, and the partial threading gives good grip without bottoming out.

The nylon pellet lock was the main reason I grabbed these, and it holds snug even under vibration from my mill. The black oxide finish looks clean and hasn’t shown any wear after a few weeks of use. These are just solid, dependable screws for jig work.