M14 Equal-End Stud Bolt (GB/T 901 / DIN 939) are specified by thread size, length and head dimensions. The M14 row from the standard is reproduced below, followed by the drill sizes, spanner size and torque values used when installing this size.
M14 Dimensional Row (GB/T 901 / DIN 939)
| Thread size | Pitch (mm) | Length L (mm) | Engagement depth bm (mm) | Material | Reference standard |
|---|---|---|---|---|---|
| M14 | 2.0 | 120 | 21 | Cl. 8.8 alloy steel | DIN 939 / GB/T 901 |
Spanner & Drive for M14 Equal-End Stud Bolt — GB/T 901 / DIN 939 (Series 093)
Drive geometry for M14 Equal-End Stud Bolt — GB/T 901 / DIN 939 (Series 093) is given by the row above; match the tool to the listed values.
Hole Sizes for M14
| Coarse-thread pitch (ISO 724) | 2 mm |
|---|---|
| Through-hole / clearance (ISO 273 medium) | 15.5 mm |
| Tapping drill, coarse thread | 12 mm |
Tightening Torque for M14
| Class 8.8 (dry, ~µ 0.125) | ≈ 135 Nm |
|---|---|
| Class 10.9 (dry, ~µ 0.125) | ≈ 190 Nm |
| Class 12.9 (dry, ~µ 0.125) | ≈ 230 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 M14
| Tensile stress area As (ISO 898-1) | 115 mm² |
|---|---|
| Proof load, class 8.8 | 67 kN |
| Proof load, class 10.9 | 95 kN |
| Proof load, class 12.9 | 112 kN |
| Min. ultimate tensile, class 8.8 | 92 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.
M14 Equal-End Stud Bolt — GB/T 901 / DIN 939 (Series 093) Weight
A steel M14 equal-end stud bolt at the listed 120 mm length weighs approximately 145 g each — about 145 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 M14 Equal-End Stud Bolt — GB/T 901 / DIN 939 (Series 093)
M14 Equal-End Stud Bolt — GB/T 901 / DIN 939 (Series 093) are commonly specified for medium-duty structural connections, automotive sub-frames and equipment chassis.
Mating Parts for M14
For M14, pair with a M14 hex nut (ISO 4032 / DIN 934) and, where used, a M14 flat washer (ISO 7089 / DIN 125A) under the head and under the nut.