M24 Left-Hand Thread Hex Bolts are manufactured to DIN 933 with a coarse thread pitch of 3 mm. This page lists the controlling dimensions for the M24 size — head geometry, width across flats, matching spanner size — together with the clearance hole, tapping drill and tightening torque used at assembly.
M24 Dimensional Row (DIN 933)
| Thread size | Pitch (mm) | Across flats s (mm) | Across corners e (mm) | Head height k (mm) | Thread direction | Common length range (mm) | Reference standard |
|---|---|---|---|---|---|---|---|
| M24 | 3.0 | 36 | 39.98 | 15.0 | Left-hand | 40~150 | DIN 933 LH |
Spanner & Drive for M24 Left-Hand Thread Hex Bolts
Drive geometry for M24 Left-Hand Thread Hex Bolts is given by the row above; match the tool to the listed values.
Hole Sizes for M24
| Coarse-thread pitch (ISO 724) | 3 mm |
|---|---|
| Through-hole / clearance (ISO 273 medium) | 26 mm |
| Tapping drill, coarse thread | 21 mm |
Tightening Torque for M24
| Class 8.8 (dry, ~µ 0.125) | ≈ 726 Nm |
|---|---|
| Class 10.9 (dry, ~µ 0.125) | ≈ 1034 Nm |
| Class 12.9 (dry, ~µ 0.125) | ≈ 1210 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 M24
| Tensile stress area As (ISO 724) | 353 mm² |
|---|---|
| Proof load, class 8.8 | 212 kN |
| Proof load, class 10.9 | 293 kN |
| Proof load, class 12.9 | 342 kN |
| Min. ultimate tensile load, class 8.8 | 293 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.
M24 Left-Hand Thread Hex Bolts Weight
A steel M24 left-hand thread hex bolts at the listed 40,150 mm length weighs approximately 142,715 g each — about 142,715 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.
Installation Tips for M24 Left-Hand Thread Hex Bolts
- At M24 the stretch in the bolt becomes the controlling factor — for critical joints, use angle-controlled or stretch-controlled tightening instead of pure torque.
Mating Parts for M24
For M24, pair with a M24 hex nut (ISO 4032 / DIN 934) and, where used, a M24 flat washer (ISO 7089 / DIN 125A) under the head and under the nut.
Custom manufacturing · Made to drawing
Need left-hand thread hex bolts in a size this table does not list?
This page covers M24 left-hand thread hex bolts. Head form and drive can be specified to the assembly rather than to a standard: a larger bearing face, a security drive, or a socket sized for the tool already on the bench. Made by cold heading or hot forging.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
