براغي رأس أسطوانية M20-2.5 × 40 مم | محرك سداسي | ملولبة بالكامل | فئة 12.9 من سبائك الصلب مع أكسيد أسود حراري (25 / عبوة)

The black oxide finish on these screws is genuinely slick, and the hex socket drive seated perfectly with my Allen key the first time. For a 12.9 alloy steel cap screw at this length, they feel dense and solid—no wobble when torquing down my fixture plates. Exactly what I wanted for precision work.

The black oxide finish on these screws looks professional and seems durable—I used them for a jig build and they threaded cleanly without any binding. For the price of a 25-pack, the Class 12.9 strength is a solid deal.

I was able to tighten them into a steel jig without stripping the hex socket at all. The 12.9 alloy steel feels incredibly solid, though a bit pricier than I'd hoped for this size.