Clutch (pin fastener) - Wikipedia

Gearbox Clutch CVs - Renovating 5 speed change mechanism Pt1 - VW T25(T3)-Tech

List of screw drives - Wikipedia

Lapel pin - Wikipedia

Machine Element Wikipedia (1), PDF, Machines

Dating Metallic Insignia: Clutch Fasteners

2.25x.5x.5 (approx) steel bar with rounded upper surface containing two unequally spaced circular fasteners(?) with small round dimples. [Not typical screw fastener] What is this for? : r/whatisthisthing

How to Wear a Lapel Pin (with Pictures) - wikiHow

Linchpin - Wikipedia

Steel bolt, probably stainless, with a tiny hole drilled through head. Keychain with cm for scale : r/whatisthisthing

אנטוניו נרי (איש עסקים) - Clutch (pin fastener) - Wikipedia