Hex socket head cap screw(Nihon Byora(Coarse Steel Zinc plated(Silver) 30 X 140 Pitch 3.5

This is a bolt with a cylindrical head featuring a hexagonal socket.
Tightening is performed using a hex key (Allen wrench). Although classified as a bolt, it is most commonly used without a nut.
It is also known as a cap screw or socket screw. Unlike open-end spanners or wrenches used to tighten hex bolts, which require clearance space around the fastener, a hex key requires no such surrounding space.
For this reason, the use of hex socket head cap screws enables work in confined spaces and contributes to the miniaturization of machinery.
Their appearance has also led to their increasing use for decorative and design purposes.

• Hex socket head cap screw Nihon Byora Coarse pitch
• Nominal diameter (d) M30
• Length under head (ℓ) 140.0
• Pitch (P) 3.5
• Thread length (b) Reference 72
• Head diameter (dk) Max 45.39 Min 44.61
• Neck diameter (da) Max 33.4
• Body diameter (ds) Max 30.00 Min 29.67
• Head height (k) Max 30.00 Min 29.48
• Under-head fillet (r) Min 1.0
• Hex socket width across flats (S) Nominal 22.0 Max 22.275 Min 20.065
• Hex socket depth (t) Min 15.5
• Head chamfer (v) Max 3.0