Dimensional data for M5 Thin Hex Nut to GB/T 6172.1 / ISO 4035, 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.
M5 Dimensional Row (GB/T 6172.1 / ISO 4035)
| Size | Pitch (mm) | Width across flats s (mm) | Width across corners e (mm) | Nut height m (mm) | Reference standard |
|---|---|---|---|---|---|
| M5 | 0.8 | 8.0 | 8.79 | 2.7 | ISO 4035 / GB/T 6172 |
Spanner & Drive for M5 Thin Hex Nut — GB/T 6172.1 / ISO 4035 (Series 055)
M5 Thin Hex Nut — GB/T 6172.1 / ISO 4035 (Series 055) have a width across flats of 8.0 mm — fit a 8.0 mm open-ended spanner or socket. In tight access a 6-point socket on the 8.0 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 M5
| Class 8.8 (dry, ~µ 0.125) | ≈ 5.9 Nm |
|---|---|
| Class 10.9 (dry, ~µ 0.125) | ≈ 8.7 Nm |
| Class 12.9 (dry, ~µ 0.125) | ≈ 10 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 M5
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 M5 Thin Hex Nut — GB/T 6172.1 / ISO 4035 (Series 055)
- 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.
- At M5 the joint is sensitive to over-torque — use a torque-limiting driver and check the head doesn't bury into a softer counterpart.
Mating Parts for M5
Pair M5 with the matching M5 bolt or screw, plus a M5 flat washer where required to distribute load on softer materials.
Custom manufacturing · Made to drawing
Need thin hex nut in a size this table does not list?
This page covers M5 thin hex nut. Thread size is the obvious variable and rarely the interesting one — height for clearance, across-flats for the tool already in the cell, and the locking feature for the vibration actually present. Made by cold heading or tapping.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.

