M3 is one of the standard coarse-thread sizes for slotted set screws with cone point under ISO 7434. The sections below reproduce the dimensional row, list the matching tools and hole sizes, and summarize where this size is normally specified.
M3 Dimensional Row (ISO 7434)
| Size | dt_max (mm) | n_nom (mm) | n_min (mm) | n_max (mm) | t_nom_min (mm) | t_max (mm) | Length range l (mm) | Reference standard |
|---|---|---|---|---|---|---|---|---|
| M3 | 0.3 | 0.4 | 0.46 | 0.6 | 0.8 | 1.05 | 4~16 | ISO 7434 |
Spanner & Drive for M3 Slotted Set Screws with Cone Point
The hex socket for M3 Slotted Set Screws with Cone Point 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 M3
| Coarse-thread pitch (ISO 724) | 0.5 mm |
|---|---|
| Through-hole / clearance (ISO 273 medium) | 3.4 mm |
| Tapping drill, coarse thread | 2.5 mm |
Tightening Torque for M3
| Class 8.8 (dry, ~µ 0.125) | ≈ 1.3 Nm |
|---|---|
| Class 10.9 (dry, ~µ 0.125) | ≈ Nm |
| Class 12.9 (dry, ~µ 0.125) | ≈ 2.2 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 M3
Set screws are rated to ISO 898-5 by hardness, because they work in compression against a shaft rather than in tension. ISO 898-1 excludes them, and a set screw has no head to preload against, so neither a property class nor a preload torque applies. Seating torque depends on the point form and the shaft material.
M3 Slotted Set Screws with Cone Point Weight
A steel M3 slotted set screws with cone point at the listed 416 mm length weighs approximately 23 g each — about 23 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.
Installation Tips for M3 Slotted Set Screws with Cone Point
- Use a quality Allen key fully seated in the socket — partial engagement is the most common cause of stripped sockets at this size.
- For countersunk and button-head variants, chamfer the through-hole to seat the head flush without preloading the head/shank fillet.
- At M3 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 M3
For M3, pair with a M3 hex nut (ISO 4032 / DIN 934) and, where used, a M3 flat washer (ISO 7089 / DIN 125A) under the head and under the nut.
Custom manufacturing · Made to drawing
Need slotted set screws with cone point in a size this table does not list?
This page covers M3 slotted set screws with cone point. 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 warm forging.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
