DIN 7984Low socket headHexagon socket

DIN 7984 M16 × 100 Low socket head

DIN 7984 M16 × 100 is a low head socket cap screw with a 100 mm nominal length, on a M16 × 1.5 mm metric thread. Same cylindrical hex socket head as DIN 912 but with roughly half the head height, for assemblies with limited vertical clearance. Lower head means lower permissible preload than a standard DIN 912 of the same size.

Dimensioned drawing — DIN 7984 M16 × 100k 9L 100⌀24⌀16
DIN 7984 M16 × 100 — Low socket headNominal dimensions in mm · Not to scale
Diameter16 mm
Length100 mm
Pitch1.5 mm
Socket size s10 mm
Head Ø dk24 mm
HeadLow socket head
DriveHexagon socket

Dimensions

Standard
DIN 7984
Type
Low head socket cap screw
Size
M16 × 100
Length L
100 mm
Socket size s
10 mm
Head diameter dk
24 mm
Head height k
9 mm
Drive
Hexagon socket
Head
Low socket head

Nominal values in millimetres as published in DIN 7984. Estimated weight 189.795 g per piece in steel (191.004 g in stainless), calculated from the nominal geometry — real parts vary with tolerance and head chamfers.

DesignationM16 × 1.5 fine
Pitch1.5 mm
Nominal Ø16 mm
Pitch Ø15.03 mm
Minor Ø ext14.16 mm
Tap drillØ 14.5 mm

Other lengthsDIN 7984 M16

All M16 specifications

Choosing and fitting this size

DIN 7984 M16 × 100 is a low socket head in M16, 100 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, M16 × 1.5 mm takes a 14.5 mm tap drill, and the external thread's minor diameter is 14.16 mm — that is the section carrying the load, not the nominal M16 figure. Thread engagement of at least one times the nominal diameter is what lets the bolt fail before the thread strips.