The M18 size of Eye Bolts is dimensioned by DIN 580. The tables below give the dimensional row from the standard, the drill and spanner sizes that go with it, and the assembly torque per property class. The technical drawing on this page redraws to the exact values selected.
M18 Dimensional Row (DIN 580)
| Thread size | Pitch (mm) | Ring inside diameter d (mm) | Ring outside diameter (mm) | Thread length (mm) | Max load vertical (kg) | Reference standard | Notes |
|---|---|---|---|---|---|---|---|
| M18 | 2.5 | 50 | 90 | 36 | 930 | DIN 580 / WLL | Drop-forged lifting eye bolt, vertical pull |
Spanner & Drive for M18 Eye Bolts
Drive geometry for M18 Eye Bolts is given by the row above; match the tool to the listed values.
Hole Sizes for M18
| Coarse-thread pitch (ISO 724) | 2.5 mm |
|---|---|
| Through-hole / clearance (ISO 273 medium) | 20 mm |
| Tapping drill, coarse thread | 15.5 mm |
Tightening Torque for M18
| Class 8.8 (dry, ~µ 0.125) | ≈ 290 Nm |
|---|---|
| Class 10.9 (dry, ~µ 0.125) | ≈ 405 Nm |
| Class 12.9 (dry, ~µ 0.125) | ≈ 485 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 M18
| Tensile stress area As (ISO 898-1) | 192 mm² |
|---|---|
| Proof load, class 8.8 | 115 kN |
| Proof load, class 10.9 | 159 kN |
| Proof load, class 12.9 | 186 kN |
| Min. ultimate tensile, class 8.8 | 154 kN |
Proof load = stress area × proof stress per ISO 898-1. Design joints so the working preload stays below the proof load of the selected class.
M18 Eye Bolts Weight
A steel M18 eye bolts at the listed 36 mm length weighs approximately 555 g each — about 555 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.
Common Applications for M18 Eye Bolts
M18 Eye Bolts are commonly specified for structural steelwork, heavy machinery foundations and large flange joints.
Installation Tips for M18 Eye Bolts
- At M18 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 M18
For M18, pair with a M18 hex nut (ISO 4032 / DIN 934) and, where used, a M18 flat washer (ISO 7089 / DIN 125A) under the head and under the nut.