M4 Screw Size Chart – Head Dimensions, Drive Sizes & Thread Pitch | Monster Bolts
M4 screw and bolt sizes are common across furniture, automotive, 3D printing, and light machinery. Use this quick chart to find head height, head diameter, and drive size for popular M4 types. If you’re new to standards, DIN and ISO numbers are the exact identifiers that define official dimensions (e.g., DIN 912, ISO 7380). Standard coarse thread for M4 is M4-0.70.
Metric M4-0.70 (Coarse) – Dimensions & Drive Sizes
| Type | DIN | ISO | Head Height | Head Diameter | Drive Size |
|---|---|---|---|---|---|
| M4 Hex Bolts (FT) | 933 | 4017 | 2.93 mm | 7.66 mm* | 7 mm WAF |
| M4 Hex Bolts (PT) | 931 | 4014 | 2.93 mm | 7.66 mm* | 7 mm WAF |
| M4 Socket Head Cap | 912 | 4762 | 4.0 mm | 7.22 mm | 3 mm hex |
| M4 Low Head Socket Cap | 7984 | — | 2.8 mm | 7.0 mm | 2.5 mm hex |
| M4 Button Head Socket | 9427 | 7380 | 2.20 mm | 7.60 mm | 2.5 mm hex |
| M4 Flat Head Socket | 7991 | 10642 | 2.48 mm | 8.96 mm | 2.5 mm hex |
| M4 Phillips Flat Head | 965 | — | 2.2 mm | 7.5 mm | #2 Phillips |
| M4 Phillips Pan Head | 7985 | 7045 | 3.25 mm | 8.0 mm | #2 Phillips |
All of these pair with matching M4 nuts and M4 washers.
Legend: PT = Partial Thread, FT = Full Thread. * = Width Across Flats (hex).
- Metric Thread Pitch Table • US TPI (comparison)
- How to Measure Length & Diameter • Printable Ruler (to scale)
- Shop all M4 fasteners — fast shipping from Milton, Florida.
M4 FAQs
What hex key fits an M4 socket head cap screw?
Typically a 3 mm hex key. Low-head and button socket styles commonly use a 2.5 mm hex.
What nut fits an M4 screw?
M4 screws pair with M4 nuts and M4 washers. Metric fasteners always match by nominal diameter.
What is the standard M4 thread pitch?
Standard coarse pitch is M4-0.70. Fine-pitch variants exist but are less common—always verify your tapped hole or nut.
Is an M4 the same as #8-32?
M4 (~0.157" diameter) is close to #8-32 (~0.164"), but they are not interchangeable due to different diameter and thread systems.