Dimensional data for M14 Hex Nuts, Grade C to ISO 4034, with the drive and the installation notes for this type.
Values are taken from the governing standard rather than from a general machine-thread table, because this type is not selected on one.
M14 Dimensional Row (ISO 4034)
| Size | Pitch (mm) | Width across flats s (mm) | Width across corners e min (mm) | Nut height m (mm) | Product grade | Reference standard |
|---|---|---|---|---|---|---|
| M14 | 2.0 | 21.0 | 22.78 | 12.8 | Grade C | ISO 4034 (DIN 555 specifies a smaller width across flats at this size) |
Spanner & Drive for M14 Hex Nuts, Grade C
M14 Hex Nuts, Grade C have a width across flats of 21.0 mm — fit a 21.0 mm open-ended spanner or socket. In tight access a 6-point socket on the 21.0 mm flats gives the most engagement per degree of swing. Where the joint is torqued to a figure, a click wrench is the only way to reproduce it across a batch.
Tightening Torque for M14
| Class 8.8 (dry, ~µ 0.125) | ≈ 134 Nm |
|---|---|
| Class 10.9 (dry, ~µ 0.125) | ≈ 197 Nm |
| Class 12.9 (dry, ~µ 0.125) | ≈ 231 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
Nuts are graded to ISO 898-2 by the proof load the nut itself will hold (classes 04, 05, 5, 6, 8, 10 and 12), not by the 8.8 / 10.9 / 12.9 scale used for bolts. A class-8 nut is the correct mate for a class-8.8 bolt, and the joint is designed on the bolt, so no bolt-tension figure is quoted here.
Installation Tips for M14 Hex Nuts, Grade C
- Use a 6-point socket where access allows — 12-point sockets are more prone to rounding the corners on smaller sizes.
- Serrated flanges need to sit directly on the joint face. A washer between the two removes the bite and leaves an ordinary bolted joint that is believed to be a locking one.
Mating Parts for M14
Pair M14 with the matching M14 bolt or screw, plus a M14 flat washer where required to distribute load on softer materials.
Custom manufacturing · Made to drawing
Need hex nuts, grade c in a size this table does not list?
This page covers M14 hex nuts, grade c. Locking method is specifiable independently of the rest: nylon insert, all-metal deformed thread, serrated flange, or none. Made by cold heading or tapping.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
