This page covers M12 Hex Bolts, Fine Pitch to ISO 8765: the full dimensional row, hole and tool sizes, proof-load data and typical applications. All values are taken from the governing standards (ISO 8765 together with ISO 273, ISO 724 and ISO 898-1 where applicable).
M12 Dimensional Row (ISO 8765)
| Size | Fine pitch (mm) | Width across flats s (mm) | Head height k (mm) | Stress area As (mmu00b2) | Common length range (mm) | Property class | Reference standard |
|---|---|---|---|---|---|---|---|
| M12 | 1.25 | 18.0 | 7.5 | 92.1 | 30~120 | 8.8 / 10.9 | ISO 8765 |
Spanner & Drive for M12 Hex Bolts, Fine Pitch
Drive geometry for M12 Hex Bolts, Fine Pitch is given by the row above; match the tool to the listed values.
Hole Sizes for M12
| Coarse-thread pitch (ISO 724) | 1.25 mm |
|---|---|
| Through-hole / clearance (ISO 273 medium) | 13.5 mm |
| Tapping drill, coarse thread | 10.75 mm |
Tightening Torque for M12
| Class 8.8 (dry, ~µ 0.125) | ≈ 92 Nm |
|---|---|
| Class 10.9 (dry, ~µ 0.125) | ≈ 135 Nm |
| Class 12.9 (dry, ~µ 0.125) | ≈ 158 Nm |
Indicative dry-joint values. Lubrication can lower the required torque by 15–25%. Always confirm against the joint design, especially when going up a strength class.
Proof Load & Strength for M12
| Tensile stress area As (ISO 724) | 92.1 mm² |
|---|---|
| Proof load, class 8.8 | 53 kN |
| Proof load, class 10.9 | 76 kN |
| Proof load, class 12.9 | 89 kN |
| Min. ultimate tensile load, class 8.8 | 74 kN |
Proof load = tensile stress area × the proof stress Sp of the class, per ISO 898-1 — Sp is a lower figure than the yield stress Rp0.2 and the two are not interchangeable. The stress area is computed from this size's own diameter and pitch, so a fine-pitch designation gives the fine-pitch figure. Design the joint so the working preload stays below the proof load of the class selected.
M12 Hex Bolts, Fine Pitch Weight
A steel M12 hex bolts, fine pitch at the listed 30,120 mm length weighs approximately 26,757 g each — about 26,757 kg per 1,000 pieces. Stainless A2/A4 weighs roughly the same (density 7.9–8.0 g/cm³).
Actual weight varies slightly with head form, thread and finish; use this figure for freight estimation only.
Mating Parts for M12
For M12, pair with a M12 hex nut (ISO 4032 / DIN 934) and, where used, a M12 flat washer (ISO 7089 / DIN 125A) under the head and under the nut.
When to Step Up or Down from M12
When the joint preload approaches the proof load of M12 class 8.8, step up to M16 class 8.8 (or move to M12 class 10.9). When the joint is over-specified, M10 often saves weight and cost without losing the safety margin.
Custom manufacturing · Made to drawing
Need hex bolts, fine pitch in a size this table does not list?
This page covers M12 hex bolts, fine pitch. Thread size and pitch, length, property class, drive form, head geometry and head marking are all specifiable — the standard part is where it starts, not where it stops. Made by cold heading or hot forging.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
