ISO 1580 M3 × 25 Pan head
ISO 1580 M3 × 25 is a pan head screw with a 25 mm nominal length, on a M3 × 0.5 mm metric thread. ISO equivalent of DIN 85.
Dimensions
- Standard
- ISO 1580
- Type
- Pan head screw
- Size
- M3 × 25
- Thread
- M3 × 0.5
- Length L
- 25 mm
- Head diameter dk
- 5.6 mm
- Head height k
- 1.8 mm
- Drive
- Slotted
- Head
- Pan head
Nominal values in millimetres as published in ISO 1580. Estimated weight 1.735 g per piece in steel (1.746 g in stainless), calculated from the nominal geometry — real parts vary with tolerance and head chamfers.
Thread data
Full M3 thread pageOther lengthsISO 1580 M3
All M3 specificationsInterchangeability
ISO 1580 is catalogued with DIN 85 as its equivalent designation. Dimensions are compared field by field rather than assumed identical.
Choosing and fitting this size
ISO 1580 M3 × 25 is a pan head in M3, 25 mm long under the head, on a 0.5 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, M3 × 0.5 mm takes a 2.5 mm tap drill, and the external thread's minor diameter is 2.39 mm — that is the section carrying the load, not the nominal M3 figure. Thread engagement of at least one times the nominal diameter is what lets the bolt fail before the thread strips.