M6 Sex Bolts & Barrel Nuts (Trade series (barrel nut and mating screw)) are specified by thread size, length and head dimensions. The M6 row from the standard is reproduced below, followed by the drill sizes, spanner size and torque values used when installing this size.
M6 Dimensional Row (Trade series (barrel nut and mating screw))
| Screw thread | Barrel diameter (mm) | Barrel length (mm) | Grip (material thickness, mm) | Head diameter dk (mm) | Head height k (mm) | Drive | Material |
|---|---|---|---|---|---|---|---|
| M6 | 9.5 | 25 | 25 | 14.0 | 3.0 | Slotted / TX | Brass / A2 stainless |
Spanner & Drive for M6 Sex Bolts & Barrel Nuts
Drive geometry for M6 Sex Bolts & Barrel Nuts is given by the row above; match the tool to the listed values.
Hole Sizes for M6
| Coarse-thread pitch (ISO 724) | 1 mm |
|---|---|
| Through-hole / clearance (ISO 273 medium) | 6.6 mm |
| Tapping drill, coarse thread | 5 mm |
Tightening Torque for M6
| Class 8.8 (dry, ~µ 0.125) | ≈ 10 Nm |
|---|---|
| Class 10.9 (dry, ~µ 0.125) | ≈ 15 Nm |
| Class 12.9 (dry, ~µ 0.125) | ≈ 17 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 M6
| Tensile stress area As (ISO 724) | 20.1 mm² |
|---|---|
| Proof load, class 8.8 | 12 kN |
| Proof load, class 10.9 | 17 kN |
| Proof load, class 12.9 | 20 kN |
| Min. ultimate tensile load, class 8.8 | 16 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.
M6 Sex Bolts & Barrel Nuts Weight
A steel M6 sex bolts & barrel nuts at the listed 25 mm length weighs approximately 30 g each — about 30 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.
Mating Parts for M6
For M6, pair with a M6 hex nut (ISO 4032 / DIN 934) and, where used, a M6 flat washer (ISO 7089 / DIN 125A) under the head and under the nut.
When to Step Up or Down from M6
When the joint preload approaches the proof load of M6 class 8.8, step up to M8 class 8.8 (or move to M6 class 10.9). When the joint is over-specified, M5 often saves weight and cost without losing the safety margin.
Custom manufacturing · Made to drawing
Need sex bolts & barrel nuts in a size this table does not list?
This page covers M6 sex bolts & barrel nuts. Thread size and pitch, length, property class, drive form, head geometry and head marking are all specifiable — the standard part is where it starts, not where it stops. Made by cold heading or hot forging.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
