براغي رأس مقبس 1/2-13 × 4-1/2 بوصة | محرك مقبس سداسي | رقعة نايلون | خيط جزئي | فولاذ سبائكي أكسيد أسود حراري (25/عبوة)

The nylon patch is a nice touch—these lock in place without needing thread locker, and the black oxide finish feels solid for shop use. I’ve got them holding a fixture together and they’ve stayed tight through a few heavy cycles.

I needed these for a jig repair and the thermal black oxide finish seems really durable. The nylon patch holds them snug without needing a separate locking washer.

The nylon patch on the threads is a huge time-saver—no more messing with liquid threadlocker on these 4-1/2" screws. They drove perfectly into my steel fixture plate with just a hex key. Exactly what I needed for a sturdy machine base.