7/8-9 x 3-1/2" 重型六角頭螺絲 | ASTM A193 B7 合金鋼 無鍍層 | 部分螺紋 (50 / 包)

Finally found some heavy hex bolts that actually fit my coupling flanges without slop; the threads are clean and the partial threading gives a solid grip without bottoming out. These B7s torqued to spec without any galling.

Just torqued these down on a pump base today, the threads were clean and the hex heads held a socket without slipping. Looks like they'll handle heavy loads just fine.

I needed something tough for a machine frame repair, and the partially threaded design on these made it easy to get a tight fit. The hex heads held up beautifully under my impact wrench without stripping.