BSF 1/4" 5/16" 3/8" 7/16" 1/2" Innensechskantschraube Senkkopf HT 10.9

BSF Socket Screw Countersunk 10.9 HT 1/4" 5/16" 3/8" 7/16" 1/2" BSF 1/4", 5/16", 3/8", 7/16", 1/2", Fine Pitch, High Tensile 10.9, Self Colour. They are tightened and loosened with an allen/ hex key drive.

eBay