M4 Flanged Button Head Socket Screws (Trade series (flanged button head)) are specified by thread size, length and head dimensions. The M4 row from the standard is reproduced below, followed by the drill sizes, spanner size and torque values used when installing this size.
M4 Dimensional Row (Trade series (flanged button head))
| Thread size | Pitch (mm) | Flange diameter dc (mm) | Head height k (mm) | Hex socket s (mm) | Bearing area vs plain button | Common length range (mm) | Property class |
|---|---|---|---|---|---|---|---|
| M4 | 0.7 | 9.4 | 2.20 | 2.5 | approx. 1.9x | 6~30 | 10.9 |
Spanner & Drive for M4 Flanged Button Head Socket Screws
The hex socket for M4 Flanged Button Head Socket Screws is shown in the spec table — use the matching Allen / hex key (an ISO 2936 hex key set covers the full range). A T-handle key gives the most feel when you are judging preload by hand; anything repeated across a batch wants a torque-controlled driver instead.
Hole Sizes for M4
| Coarse-thread pitch (ISO 724) | 0.7 mm |
|---|---|
| Through-hole / clearance (ISO 273 medium) | 4.5 mm |
| Tapping drill, coarse thread | 3.3 mm |
Tightening Torque for M4
| Class 8.8 (dry, ~µ 0.125) | ≈ 2.9 Nm |
|---|---|
| Class 10.9 (dry, ~µ 0.125) | ≈ Nm |
| Class 12.9 (dry, ~µ 0.125) | ≈ 5 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 M4
This is a reduced-height head. The head, not the thread, limits what the screw will carry — ISO 7380-1 caps a button head at roughly 80% of the thread's capacity — so the thread's proof load overstates the assembly. Size the joint on the head, or use a cap screw where the full class strength is needed.
M4 Flanged Button Head Socket Screws Weight
A steel M4 flanged button head socket screws at the listed 630 mm length weighs approximately 343 g each — about 343 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 M4
For M4, pair with a M4 hex nut (ISO 4032 / DIN 934) and, where used, a M4 flat washer (ISO 7089 / DIN 125A) under the head and under the nut.
When to Step Up or Down from M4
When the joint preload approaches the proof load of M4 class 8.8, step up to M5 class 8.8 (or move to M4 class 10.9). When the joint is over-specified, M3 often saves weight and cost without losing the safety margin.
Custom manufacturing · Made to drawing
Need flanged button head socket screws in a size this table does not list?
This page covers M4 flanged button head socket screws. Where the standard stops, the drawing takes over: fine pitches, left-hand threads, partial threading, and property classes above the catalogued grade where material and heat treatment allow. Made by cold heading or warm forging.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
