HOLO-KROME 08016 5/16" X 3/8" 內六角肩螺絲 | 內六角頭 | 內六角驅動 | 合金鋼熱處理黑色氧化（25 個／包）

The precision ground shoulder on these screws made dialing in the pivot point on my jig effortless, and the hex drive seated perfectly without any stripping. They fit tight and smooth right out of the box.

I needed a strong shoulder screw for a custom jig, and the precision ground surface on these made for a snug fit in the bushing. Worked perfectly for the pivot point I was setting up. Only complaint is the black oxide finish seems a bit thin in spots, but they still hold well.

I used these as pivot pins in a small assembly, and the hex socket drive made installation simple. The precision ground shoulder fit snugly into the bearing surface without any wobble. Only ding is the black oxide finish seems a bit thin, but they work well for the price.