براغي ذات رأس أسطواني 1/2-13 × 4 بوصة | محرك سداسي | صناعة أمريكية | فولاذ سبائكي مع أكسيد أسود حراري (25 / عبوة)

The black oxide finish on these screws held up perfectly during my lathe tooling setup — no chips or wear after tightening. Fit the hex socket snugly without any stripping. Solid, heavy-duty threads that threaded smoothly into my fixture plate.

Needed a few of these for a jig I was building and the 1/2-13 threads cut cleanly into the pre-tapped holes without any binding. The hex socket drive made installation easy with my Allen wrench set, and the alloy steel feels sturdy enough for repetitive use.

Finally, a bolt that meets the 1/2-13 spec perfectly without any slop in the threads. The black oxide finish on these alloy steel screws seems really durable for jig and fixture work.