براغي رأس مقبس سداسي | 5/16-18 × 2-1/8" | محرك سداسي | خيط جزئي | سبيكة فولاذ معالجة حرارياً بأكسيد أسود (100/عبوة)

Used a handful of these to build a custom jig for my drill press, and the black oxide finish held up perfectly against metal shavings. The hex socket drive made installation quick, even in tight spots.

The partial threading on these is perfect for clamping down on thicker plates without the threads chewing up the bore. Black oxide finish looks consistent across all 100 pieces, and the alloy steel feels solid when torqued down on my jig.

The hex socket drive gives a much cleaner grip than a regular hex head, and the thermal black oxide finish looks great on my tooling jig. Packed a hundred of them into storage without a single burr or defect.