ISO 7380Button head (low dome)Hexagon socket

ISO 7380 M12 × 50 Button head (low dome)

ISO 7380 M12 × 50 is a button head socket screw with a 50 mm nominal length, on a M12 × 1.5 mm metric thread. A low dome head with internal hex drive. Chosen when you want a finished look without machining a countersink.

Dimensioned drawing — ISO 7380 M12 × 50k 6.6L 50⌀21⌀12
ISO 7380 M12 × 50 — Button head (low dome)Nominal dimensions in mm · Not to scale
Diameter12 mm
Length50 mm
Pitch1.5 mm
Socket size s8 mm
Head Ø dk21 mm
HeadButton head (low dome)
DriveHexagon socket

Dimensions

Standard
ISO 7380
Type
Button head socket screw
Size
M12 × 50
Length L
50 mm
Socket size s
8 mm
Head diameter dk
21 mm
Head height k
6.6 mm
Drive
Hexagon socket
Head
Button head (low dome)

Nominal values in millimetres as published in ISO 7380. Estimated weight 62.336 g per piece in steel (62.733 g in stainless), calculated from the nominal geometry — real parts vary with tolerance and head chamfers.

DesignationM12 × 1.5 fine
Pitch1.5 mm
Nominal Ø12 mm
Pitch Ø11.03 mm
Minor Ø ext10.16 mm
Tap drillØ 10.5 mm

Other lengthsISO 7380 M12

All M12 specifications

Choosing and fitting this size

ISO 7380 M12 × 50 is a button head (low dome) in M12, 50 mm long under the head, on a 1.5 mm coarse pitch. Mating threads should be a matching class nut or a tapped hole of the same nominal size.

Common stock grades are 8.8, 10.9 and 12.9 in steel, plus A2-70 and A4-80 in stainless. Class 10.9 and 12.9 carry roughly 1.25 and 1.5 times the proof load of 8.8, but they also need a properly rated mating nut — a class 8 nut under a 12.9 bolt simply moves the failure into the thread. Zinc-plated 10.9 and above should be baked to avoid hydrogen embrittlement.

For a tapped hole, M12 × 1.5 mm takes a 10.5 mm tap drill, and the external thread's minor diameter is 10.16 mm — that is the section carrying the load, not the nominal M12 figure. Thread engagement of at least one times the nominal diameter is what lets the bolt fail before the thread strips.