مسامير آلية 5/16-18 × 3-1/2 بوصة | رأس مسطح بمحرك مشقوق | فولاذ عادي (100 / العبوة)

These are the exact length I needed for a few heavy brackets; the 3-1/2" flat head sits perfectly flush in the countersunk hole. The slotted drive grabbed my screwdriver nicely without any cam-out. Exactly what you'd expect from a solid steel machine screw.

Slotted head on these 5/16-18 machine screws made it easy to get good torque with a standard flathead screwdriver. Exactly 3-1/2 inches long, which worked perfectly for a furniture repair where I needed a bit more reach. Plain steel is fine for my indoor shop jig.

I needed a longer fastener for a jig I was building, and these 3-1/2" slotted flat heads threaded in smoothly without any binding. The plain steel finish looks standard, which is fine for my indoor shop project.