Bulk vs true density
True density
Density of the stone itself, without voids. For diabase — ≈ 2.7–2.9 t/m³. A rock property, not used directly in supply maths.
Bulk density
Mass in a loose pile including voids between grains — 1.38–1.65 t/m³. Used to convert tonnes to m³ and to size truck/wagon loads.
Bulk density of HKC diabase by fraction
Indicative per GOST 8267-93 and HKC experience. Exact batch density is confirmed by the quality passport.
| Fraction | Bulk density, t/m³ | Range by batch |
|---|---|---|
| 5-10 mm | 1,52 | 1,50–1,55 t/m³ |
| 5-20 mm | 1,48 | 1,45–1,55 t/m³ |
| 10-20 mm | 1,45 | 1,42–1,50 t/m³ |
| 20-40 mm | 1,42 | 1,40–1,48 t/m³ |
| 25-60 mm | 1,40 | 1,38–1,45 t/m³ |
| 40-70 mm | 1,38 | 1,36–1,42 t/m³ |
| 0-5 mm (screenings) | 1,55 | 1,50–1,60 t/m³ |
| 0-40 mm (mix) | 1,60 | 1,55–1,65 t/m³ |
| 0-70 mm (mix) | 1,62 | 1,58–1,68 t/m³ |
| 0-80 mm (mix) | 1,65 | 1,60–1,70 t/m³ |
“Crushed stone density M1000” — a common mix-up
The query “M1000 density” is misleading: M1000 is the crushing-strength grade, not density. The grade shows the crushing load the stone withstands. Density is measured separately in t/m³ and depends on fraction. HKC diabase is strength grade M1400 (above M1000), bulk density 1.38–1.65 t/m³ per the table above.
Converting tonnes to cubic metres and back
Volume = mass ÷ bulk density
Example: 69 t of 20-40 (1.42) ≈ 49 m³
Mass = volume × bulk density
Example: 50 m³ of 5-20 (1.48) ≈ 74 t
Need to size wagons? → Crushed stone calculator
Frequently asked questions
How many tonnes in 1 m³ of crushed stone?
Bulk density is 1.38–1.55 t/m³ by fraction. Fine (5-10, 0-5 mm) ~1.5 t/m³; coarse (40-70 mm) ~1.38 t/m³. See the table above.
What is “M1000 density”?
“M1000” is not density — it is the crushing-strength grade. Density is measured in t/m³ and depends on fraction, not on the M-grade. HKC diabase is strength grade M1400, bulk density 1.38–1.65 t/m³.
Bulk vs true density?
True density of diabase (the stone itself, no voids) is ~2.7–2.9 t/m³. Bulk density accounts for voids between grains, so it is lower — 1.38–1.65 t/m³, and is used for supply and volume calculations.
How to convert tonnes to cubic metres?
Volume (m³) = mass (t) ÷ bulk density (t/m³). E.g. 69 t of 20-40 mm at 1.42 ≈ 49 m³. Reverse: mass = volume × density.