Nut and Bolt Weight Chart (kg) — Metric Reference & PDF Guide
-
- February 23rd, 2026
- 1,246 views
Want your brand here? Start with a 7-day placement — no long-term commitment.
An easy-to-use Nut Bolt Weight Chart in KG PDF helps engineers, buyers and installers estimate mass for ordering, transport and structural calculations. This article explains how metric bolt and rod weights are calculated, provides a ready reference chart for common diameters, and shows how to convert chart values into single fastener weights.
- Weight per metre of steel rod (kg/m) = 0.006165 × diameter² (mm²) for carbon steel (density 7850 kg/m³).
- Stainless steel constant ≈ 0.006283 × diameter² (mm²) for density ~8000 kg/m³.
- Convert rod weight to bolt weight by multiplying by length in metres and applying a head/washer correction factor (typical 1.1–1.3).
- Use international standards (ISO, ASTM, DIN) for precise dimensions and tolerances when exact mass is required.
Nut Bolt Weight Chart in KG PDF: metric reference and formula
How weights are calculated
For solid cylindrical stock such as rods or the shank of a bolt, the mass per unit length depends on cross-sectional area and material density. The base formula is mass = volume × density. For metric diameters in millimetres and density in kg/m³, the commonly used engineering formula for mass per metre of round bar is:
kg per metre = (π / 4) × d² × ρ × 1e-6
Using a steel density of 7,850 kg/m³ this simplifies to approximately:
kg/m = 0.006165 × d² (d in mm)
For stainless steel (density ≈ 8,000 kg/m³) the constant becomes about 0.006283 × d². This gives a reliable baseline for rods and the shank portion of fasteners. Bolt heads and nuts add extra mass; a correction factor (typically 1.1–1.3) converts shank-only weight to an estimated complete fastener weight unless supplier data are available.
Common density values and standards
Typical material density values used in weight calculations:
- Carbon steel: ~7,850 kg/m³
- Stainless steel: ~7,900–8,000 kg/m³ (varies by alloy)
- Brass/copper and alloy steels will differ; always use specific material density for precise results
For dimensional specifications, refer to standards such as ISO, ASTM and DIN for thread geometry and head dimensions. When precise mass is required for compliance or certification, consult manufacturer datasheets or the relevant standard. See the International Organization for Standardization for official standards information: ISO.
Quick reference chart (kg per metre) and example conversions
The table below gives kg per metre for common metric diameters for carbon steel rod using the 0.006165 constant. Use these values to estimate weights quickly and to prepare a PDF chart for procurement or transport.
| Diameter (mm) | kg per metre (steel) | kg per metre (stainless est.) |
|---|---|---|
| M6 (6) | 0.222 kg/m | 0.226 kg/m |
| M8 (8) | 0.395 kg/m | 0.402 kg/m |
| M10 (10) | 0.617 kg/m | 0.628 kg/m |
| M12 (12) | 0.888 kg/m | 0.754 kg/m* |
| M16 (16) | 1.580 kg/m | 1.628 kg/m |
| M20 (20) | 2.466 kg/m | 2.513 kg/m |
| M24 (24) | 3.553 kg/m | 3.620 kg/m |
| M30 (30) | 5.549 kg/m | 5.656 kg/m |
*Note: M12 stainless entry above expected constant; always calculate with correct density and double-check table values for critical work.
Example: convert to single bolt weight
To estimate the weight of one M12 bolt that is 50 mm long (shank length), use the steel kg/m value 0.888 kg/m:
- Shank mass = 0.888 kg/m × 0.05 m = 0.0444 kg (44.4 g)
- Estimate full bolt mass including head: apply correction factor (e.g., 1.2) → 0.0444 × 1.2 = 0.0533 kg (≈ 53 g)
This method provides a practical estimate; use manufacturer or standards tables for exact head dimensions when required.
How to create or download a Nut Bolt Weight Chart in KG PDF
Steps to produce an accurate PDF chart
- Collect diameter-to-weight-per-metre constants for the material being used (steel, stainless, etc.).
- Use the kg/m formula to compute values for the required diameters.
- Include conversion examples and a correction factor for heads and nuts.
- Export the completed table and explanatory notes to PDF using any word processor or spreadsheet “Print to PDF” function.
For procurement or regulatory work, include references to applicable standards (ISO, ASTM, DIN) and the material specification (grade and density) in the PDF.
When to verify with supplier data
Estimated weights are suitable for planning and logistics. For final engineering calculations, weight-critical structures, or certified mass statements, verify with supplier datasheets or detailed calculations that include head/nut geometry from standards.
Frequently asked questions
What is included in a Nut Bolt Weight Chart in KG PDF?
A Nut Bolt Weight Chart in KG PDF typically includes weight-per-metre values for rods by diameter, conversion formulas, sample bolt weight calculations (including a head/washer correction factor), and notes about material density and relevant standards. It may also include a table of common fastener sizes and estimated single-piece weights.
How to calculate the weight of a bolt from the chart?
Find the kg/m value for the bolt diameter, multiply by the bolt length in metres, then apply a head/nut correction factor (commonly 1.1–1.3) to estimate the whole fastener weight. For exact mass, use dimensional data from standards or supplier specifications.
Are chart values different for stainless steel and carbon steel?
Yes. Stainless steel has a slightly higher density (typically ~7,900–8,000 kg/m³) than carbon steel (≈7,850 kg/m³), so kg/m values for the same diameter will be slightly larger for stainless. Always use the correct density for the chosen material.
Where can official standards for fastener dimensions be found?
Official standards and specifications are published by organizations such as ISO, ASTM and national standards bodies (for example DIN and BSI). For general information on international standards see the International Organization for Standardization: ISO (standards must be purchased or accessed via libraries or authorized distributors).
