ENGINEERING TOOL
M20 Hex Nut Weight & Dimensions Chart
Unit and bulk weight (M20)
| Weight per piece (g) | Bulk weight (kg/1000 pcs) |
|---|---|
| 63.2 g | 63.2 kg/1000 pcs |
Unit weight and weight per 1,000 pcs of M20 hex nuts (width across flats per ISO 4032 / GB/T 6170-2015, modeled nut height), computed as geometric volume × density on carbon steel, with kg/1000 pcs ↔ lb/100 pcs toggle — basis fully disclosed.
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Other sizes
Nut Dimensions
| Nominal diameter d | 20 mm |
| Width across flats s | 30 mm |
| Nut height m | 16 mm |
Width across flats s follows the ISO 4032 / GB/T 6170 style-1 hex nut series; nut height m is our library's modeled dimension (ISO 4032:1999 / GB/T 6170-2000 series), identical to the catalog SKU and calculator parameters. Fine-thread nuts (GB/T 6171) share the same envelope, so this table approximates their unit weight.
References
- GB/T 6170-2015 — Style 1 hexagon nuts (CN, official full text; dimension series identical to ISO 4032:1999 / GB/T 6170-2000)
- Hex nut dimensions (ISO 4032 series)
- GB/T 192-2003 — General purpose metric screw threads: basic profile (CN, official full text; ISO 68-1 equivalent)
- Metric thread basic profile (ISO 68-1)
- Dimensions cross-checked against industry fastener data libraries; densities are common industry values
Material Density Conversion
Values above are carbon steel (7.85 g/cm³); for other materials multiply by the density factor.
| Material | Density (g/cm³) | Factor |
|---|---|---|
| Carbon / Alloy Steel | 7.85 | ×1.000 |
| Stainless 304 | 7.93 | ×1.010 |
| Stainless 316 | 7.98 | ×1.017 |
| Brass | 8.5 | ×1.083 |
Basis of Calculation & Disclosed Assumptions
Calculation basis
- All values are computed as geometric volume × density (carbon steel 7.85 g/cm³, base metal, coating excluded) — identical formula and parameters as the online weight calculator.
- Hex nut = hexagonal prism (across flats s) minus the tapped hole, whose effective diameter is d − 0.5×pitch (the mean of thread major/minor diameters with face-chamfer allowance).
- The basis is calibrated family-wide against public per-1,000-pcs weight tables.
Scope & limits
- Theoretical geometric estimates for quotation, freight and packing budgets; use measured values for trade settlement.
- Actual piece weight varies with thread tolerance, chamfer and coating (hot-dip galvanizing ≈ +4.5%).
- Note the standards difference: withdrawn DIN 934 gave M12 a width across flats of 19 mm while GB/T 6170 / ISO 4032 specify 18 mm — weights differ slightly; this chart uses GB/T 6170 across-flats with the library modelled nut height (ISO 4032:1999 / GB/T 6170-2000 series, same parameters as our catalog SKUs).
- Theoretical estimate tolerance ±5%.
Cite this chart
YAXIIO. M20 Hex Nut Weight & Dimensions Chart. https://www.yaxiio.com/en/tools/hex-nut-weight-chart/m20 (accessed 2026-10-29).
Free to cite and embed — attribution required: “YAXIIO” + a link to this page.
FAQ
What are the width across flats and height of an M20 hex nut?
Width across flats s = 30 mm (per ISO 4032 / GB/T 6170), nut height m = 16 mm (library modeled dimension, ISO 4032:1999 / GB/T 6170-2000 series — same parameters as our catalog SKUs), mating M20 bolts with 2.5 mm coarse pitch.
What nut and washers pair with an M20 bolt?
A matching M20 hex nut (ISO 4032 / GB/T 6170, about 63.2 g per piece); for flat washers (ISO 7089 / GB/T 97.1) and spring washers (GB/T 93) see our washer weight chart — both types side by side for the same size.
Next: work out your order, or pick the size by standard
Related References
Bolt Weight Calculator
Interactive version: nuts, flat/spring washers and bolt sets at any quantity, material and coating factors — this size is pre-filled.
M20 Hex Bolt Weight Chart
Per-piece and per-1,000-pcs weights for the same size, including matching nut and washer.
M20 Flat & Spring Washer Weight Chart
Same-size flat and spring washers side by side: OD, thickness and unit weight.
Hex Nut Catalog
GB/T 6170 coarse, GB/T 6171 fine and lock nuts: sizes, materials and coatings — quotation on request.
Disclaimer: This chart is an engineering estimation for selection, quotation and freight estimation only. It does not constitute design or acceptance criteria.