M3 Nylon Insert Lock Nut (Nylon Lock Nut), ISO 10511
Across the flats an M3 nylon insert lock nut (ISO 10511) measures 5.32 to 5.5 mm, and it stands 3.42 to 3.9 mm tall on the M3 × 0.5 thread. It comes as simplified and threaded STEP files.

How these parts are made, and what the levels mean: read the method
- Also searched as: M3 nut
- Model id:
iso10511-m3
- Standard: ISO 10511:2012 · thread M3 × 0.5, ISO metric coarse, right hand
Files
| Part key | Simplified | Threaded |
|---|
iso10511-m3 | STEP | STEP |
Dimensions

| Symbol | Name | min | nom | max | Modeled | Rule | Level |
|---|
| P | Thread pitch | | 0.5 | | 0.5 | nominal | L2 |
| da | Countersink diameter | 3 | | 3.45 | 3.225 | midpoint of min–max | L2 |
| dw | Bearing face diameter | 4.56 | | | 4.56 | single limit (min), modeled at the limit | L2 |
| e | Width across corners | 6.01 | | | 6.01 | single limit (min), modeled at the limit | L2 |
| h | Nut height | 3.42 | | 3.9 | 3.66 | midpoint of min–max | L2 |
| m | Hexagon height | 1.55 | | | 1.55 | single limit (min), modeled at the limit | L2 |
| mw | Wrenching height | 1.24 | | | 1.24 | single limit (min), modeled at the limit | L2 |
| s | Width across flats | 5.32 | | 5.5 | 5.41 | midpoint of min–max | L2 |
| beta | Chamfer angle | 15 | | 30 | 22.5 | midpoint of min–max | L2 |
| theta | Countersink angle | 90 | | 120 | 105 | midpoint of min–max | L2 |
| P | Coarse thread pitch | | 0.5 | | 0.5 | nominal | L1 |
| tap_drill | Tap drill diameter | | 2.5 | | 2.5 | nominal | L1 |
| d1 | Basic minor diameter | | 2.458734 | | 2.458734 | nominal | L1 |
| ch_angle | Chamfered end angle | | | 50 | 50 | single limit (max), modeled at the limit | L2 |
| dh_fine | Clearance hole, fine series | | 3.2 | | 3.2 | nominal | L1 |
| dh_medium | Clearance hole, medium series | | 3.4 | | 3.4 | nominal | L1 |
| dh_coarse | Clearance hole, coarse series | | 3.6 | | 3.6 | nominal | L1 |
Thread and holes
- Tap drill: 2.5 mm (method: d − P), L1, sources amesweb-tap-drill, rule-tap-drill.
- Clearance hole (ISO 273): close 3.2, normal 3.4, loose 3.6 mm (L1: fine, medium and coarse series (albany-clearance, wikipedia-de-clearance)).
Drawing

As a PDF: CC-ISO10511-SZ-M3.pdf.
Goes with the M3 nylon insert lock nut
The M3 nylon insert lock nut beside the M4
The M3 is the smallest of the 5 ISO 10511 nylon insert lock nuts published here, from M3 to M8.
- Thread pitch (P): 0.5 mm on the M3 nylon insert lock nut, against 0.7 mm on the M4.
- Countersink diameter (da): 3 to 3.45 mm on the M3 nylon insert lock nut, against 4 to 4.6 mm on the M4.
- Bearing face diameter (dw): at least 4.56 mm on the M3 nylon insert lock nut, against at least 5.9 mm on the M4.
- Width across corners (e): at least 6.01 mm on the M3 nylon insert lock nut, against at least 7.66 mm on the M4.
- Nut height (h): 3.42 to 3.9 mm on the M3 nylon insert lock nut, against 4.52 to 5 mm on the M4.
- Hexagon height (m): at least 1.55 mm on the M3 nylon insert lock nut, against at least 1.95 mm on the M4.
- Wrenching height (mw): at least 1.24 mm on the M3 nylon insert lock nut, against at least 1.56 mm on the M4.
- Width across flats (s): 5.32 to 5.5 mm on the M3 nylon insert lock nut, against 6.78 to 7 mm on the M4.
Other sizes
Documents
Sources
albany-clearance, amesweb-tap-drill, fasten-it-iso10511, iso10511-2012-sample, iso4753-2011-sample, rule-basic-minor, rule-tap-drill, wikipedia-de-clearance, wikipedia-iso261. Full citations: the method page and this size's datasheet.
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