M8 Nylon Insert Lock Nut (Nylon Lock Nut), ISO 10511
The M8 nylon insert lock nut (ISO 10511) is 12.73 to 13 mm across the flats and 6.18 to 6.76 mm high. The thread is M8 × 1.25; the files are simplified and threaded STEP files.

How these parts are made, and what the levels mean: read the method
- Also searched as: M8 nut
- Model id:
iso10511-m8
- Standard: ISO 10511:2012 · thread M8 × 1.25, ISO metric coarse, right hand
Files
| Part key | Simplified | Threaded |
|---|
iso10511-m8 | STEP | STEP |
Dimensions

| Symbol | Name | min | nom | max | Modeled | Rule | Level |
|---|
| P | Thread pitch | | 1.25 | | 1.25 | nominal | L2 |
| da | Countersink diameter | 8 | | 8.75 | 8.375 | midpoint of min–max | L2 |
| dw | Bearing face diameter | 11.6 | | | 11.6 | single limit (min), modeled at the limit | L2 |
| e | Width across corners | 14.38 | | | 14.38 | single limit (min), modeled at the limit | L2 |
| h | Nut height | 6.18 | | 6.76 | 6.47 | midpoint of min–max | L2 |
| m | Hexagon height | 3.7 | | | 3.7 | single limit (min), modeled at the limit | L2 |
| mw | Wrenching height | 2.96 | | | 2.96 | single limit (min), modeled at the limit | L2 |
| s | Width across flats | 12.73 | | 13 | 12.865 | 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 | | 1.25 | | 1.25 | nominal | L1 |
| tap_drill | Tap drill diameter | | 6.75 | | 6.75 | nominal | L1 |
| d1 | Basic minor diameter | | 6.646835 | | 6.646835 | nominal | L1 |
| ch_angle | Chamfered end angle | | | 50 | 50 | single limit (max), modeled at the limit | L2 |
| dh_fine | Clearance hole, fine series | | 8.4 | | 8.4 | nominal | L1 |
| dh_medium | Clearance hole, medium series | | 9 | | 9 | nominal | L1 |
| dh_coarse | Clearance hole, coarse series | | 10 | | 10 | nominal | L1 |
Thread and holes
- Tap drill: 6.75 mm (method: d − P), L1, sources amesweb-tap-drill, rule-tap-drill.
- Clearance hole (ISO 273): close 8.4, normal 9, loose 10 mm (L1: fine, medium and coarse series (albany-clearance, wikipedia-de-clearance)).
Drawing

As a PDF: CC-ISO10511-SZ-M8.pdf.
Goes with the M8 nylon insert lock nut
The M8 nylon insert lock nut beside the M6
The M8 is the largest of the 5 ISO 10511 nylon insert lock nuts published here, from M3 to M8.
- Thread pitch (P): 1.25 mm on the M8 nylon insert lock nut, against 1 mm on the M6.
- Countersink diameter (da): 8 to 8.75 mm on the M8 nylon insert lock nut, against 6 to 6.75 mm on the M6.
- Bearing face diameter (dw): at least 11.6 mm on the M8 nylon insert lock nut, against at least 8.9 mm on the M6.
- Width across corners (e): at least 14.38 mm on the M8 nylon insert lock nut, against at least 11.05 mm on the M6.
- Nut height (h): 6.18 to 6.76 mm on the M8 nylon insert lock nut, against 5.52 to 6 mm on the M6.
- Hexagon height (m): at least 3.7 mm on the M8 nylon insert lock nut, against at least 2.9 mm on the M6.
- Wrenching height (mw): at least 2.96 mm on the M8 nylon insert lock nut, against at least 2.32 mm on the M6.
- Width across flats (s): 12.73 to 13 mm on the M8 nylon insert lock nut, against 9.78 to 10 mm on the M6.
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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