M3-0.5 x 6mm Flat Head Socket Cap Screws Countersunk Bolts, Alloy Steel Class 10.9 Black Oxide, DIN 7991, Fully Threaded, 100 PCS: Amazon.com: Industrial & Scientific
BLK STL SOCKET, BSP | FITTINGS- Pipe Steel - Maximus Trade Centre
Black Steel Socket – BSP Threaded | Valve Warehouse Australia
Class 12.9 Alloy Steel Socket Cap Screw, Black Oxide Finish, Button Head, Internal Hex Drive, Meets ISO 7380, 10mm Length, Fully Threaded, M4-0.7 Metric Coarse Threads, Imported (Pack of 100): Amazon.com: Industrial