Raw material
Material weight
The number that goes into the quote before the material arrives: how much the block, the bar or the plate you're about to buy weighs. From H13 and TOOLOX 44 to engineering plastics, with the source of every density stated.
Material and shape
Also sold as 1.2344 · X40CrMoV5-1 · SKD61 · VH13ISO · ORVAR Supreme
Hot work. The most common cavity steel in injection molds.
Source: Uddeholm ORVAR Supreme: 7.80 g/cm³ at 20 °C
Dimensions
Result
Weight per piece
11.7
kg
Total (1 pcs)
11.7
kg
Volume per piece
1,500
cm³
Density used
7.8
g/cm³
What this calculation does — and what it doesn't
Density isn't an exact number
Steel density varies with composition and heat treatment, and each manufacturer publishes its own value. The differences are around 1% — irrelevant for quoting raw material, and relevant for nothing else. Nobody buys a block by the catalogue's scale.
Where the manufacturer publishes its own value, that's what's here, with the source next to the material. Where it doesn't, the family value is used.
Plastic is another story
A thermoplastic's density changes with grade, mineral filler and fibre reinforcement. Neat PP is 0.905 g/cm³; the same PP with 20% talc goes past 1.05 — almost 16% more.
That's why plastics carry a range, and the page warns when it's wide enough to change the result. If your material is filled, take the density from the supplier's datasheet and use the manual field.
Hex bar is measured across flats
That's how the supplier sells it, and the area is (2/√3)·e², not e². Using the square formula underestimates the weight by about 13% — the kind of error that only shows up when the bar arrives heavier than quoted.
It's the weight of raw stock, not of the finished part
The calculation is for the stock you buy. What leaves as chips isn't in it — and that's precisely why it works for quoting: you pay for the whole block, not the finished part.
To check the purchase, use the weight per metre: it's the number in your supplier's table, and it's where a wrong dimension shows up first.
Densities used
67 materials. The designations column is what lets you find the same steel under the name your supplier uses.
Tool steels
| Material | g/cm³ | Also called | Note |
|---|---|---|---|
| H13 | 7.8 | 1.2344 · X40CrMoV5-1 · SKD61 · VH13ISO · ORVAR Supreme | Hot work. The most common cavity steel in injection molds. |
| TOOLOX 44 | 7.85 | — | Quenched and tempered at the mill: machine it and it's ready, with no heat treatment afterwards. ~45 HRC. |
| TOOLOX 33 | 7.85 | — | Same idea as the 44, softer (~30 HRC) and easier to machine. |
| STAVAX ESR | 7.8 | 1.2083 ESR · 420 ESR | Stainless cavity steel. For PVC and wherever the part needs a high polish. |
| P20 | 7.85 | 1.2311 · 1.2312 · 1.2738 · IMPAX Supreme · VP20 | Mold base and medium-run cavities, pre-hardened to ~30 HRC. |
| NIMAX | 7.8 | — | Pre-hardened to ~40 HRC, weldable without preheating. An alternative to P20 where repairs are expected. |
| RAMAX HH | 7.75 | — | Stainless mold base steel. Used where cooling water corrodes ordinary steel. |
| CORRAX | 7.7 | — | Precipitation-hardening stainless. Almost no distortion in heat treatment. |
| D2 | 7.7 | 1.2379 · X153CrMoV12 · SKD11 · VF800AT | Cold work. Blanking, punches and dies. |
| O1 | 7.8 | 1.2510 · 100MnCrW4 · ARNE | Cold work, oil hardening. Tooling for short runs. |
| S7 | 7.83 | 1.2355 | Impact resistant. Punches and tooling that works under shock. |
| M2 | 8.14 | 1.3343 · HS6-5-2 · ABC M2 | High-speed steel. End mills, drills and cutting tools. |
| 1.2767 | 7.85 | 45NiCrMo16 · VNDC | Cold work with high toughness. Deep-drawing dies. |
| 1.2343 | 7.8 | H11 · X37CrMoV5-1 | Hot work, slightly tougher than H13. |
| 8407 Supreme | 7.8 | — | Premium remelted H13. Cavities for long production runs. |
Structural steels
| Material | g/cm³ | Also called | Note |
|---|---|---|---|
| SAE 1020 | 7.87 | — | Low carbon. Structures, supports, jigs. |
| SAE 1045 | 7.85 | — | Medium carbon. Shafts, plates, pillars. |
| SAE 4140 | 7.85 | 1.7225 · 42CrMo4 · VC131 | Quenched and tempered. Shafts and components under load. |
| SAE 8620 | 7.85 | 1.6523 | Case hardening. Gears and pins. |
| ASTM A36 | 7.85 | — | Structural, plate and section. |
Stainless steels
| Material | g/cm³ | Also called | Note |
|---|---|---|---|
| Stainless 304 | 7.9 | 1.4301 · A2 | — |
| Stainless 316 | 8 | 1.4401 · A4 | Chloride resistance. Food industry and marine environments. |
| Stainless 420 | 7.7 | 1.2083 | Martensitic, hardenable. Cutlery and cavities. |
| Stainless 430 | 7.7 | 1.4016 | — |
| Stainless 17-4 PH | 7.78 | 1.4542 · 630 | — |
Non-ferrous
| Material | g/cm³ | Also called | Note |
|---|---|---|---|
| Aluminium 6061 | 2.7 | — | General purpose. Jigs, fixtures, prototypes. |
| Aluminium 6063 | 2.7 | — | Extruded section. |
| Aluminium 7075 | 2.81 | — | High strength. Aerospace and blow molds. |
| Aluminium 5052 | 2.68 | — | Bent sheet, corrosion resistant. |
| Aluminium 1050 | 2.71 | — | Pure and soft. Conduction and shallow pressings. |
| Aluminium 7050 / Alumold | 2.83 | — | Aluminium mold plate, for short runs and prototyping. |
| Brass | 8.5 (8.4–8.7) | CuZn37 · C36000 | Density varies with the zinc content. |
| Bronze | 8.8 (8.7–8.9) | CuSn · SAE 65 | Bushings and guides. |
| Graphite-filled bronze | 8.5 | — | Self-lubricating mold bushings. |
| Copper | 8.96 | Cu-ETP · C11000 | EDM electrodes and cooling inserts. |
| Beryllium copper | 8.25 | CuBe2 · Ampcoloy 940 | Heat-transfer insert for hot spots in the mold. |
| Graphite (EDM electrode) | 1.78 (1.7–1.9) | — | EDM electrode. Density changes with grain size. |
| Zamak 5 | 6.6 | — | Zinc die casting. |
| Titanium Grade 5 | 4.43 | Ti-6Al-4V | — |
| Magnesium AZ91 | 1.81 | — | — |
| Lead | 11.34 | — | — |
Plastics
| Material | g/cm³ | Also called | Note |
|---|---|---|---|
| PP — polypropylene | 0.905 (0.89–0.92) | — | Mineral filler raises it a lot: PP with 20% talc comes close to 1.05. |
| HDPE | 0.955 (0.94–0.97) | PE300 · PE500 | — |
| LDPE | 0.922 (0.91–0.94) | — | — |
| PS — polystyrene | 1.05 | GPPS | — |
| ABS | 1.05 (1.03–1.07) | — | — |
| PA6 — nylon | 1.14 (1.12–1.15) | — | With 30% glass fibre it reaches ~1.36. |
| PA66 | 1.14 (1.13–1.15) | — | — |
| PC — polycarbonate | 1.2 | — | — |
| POM — acetal | 1.41 (1.39–1.43) | Delrin | — |
| PMMA — acrylic | 1.19 | — | — |
| PET | 1.38 (1.33–1.4) | — | — |
| Rigid PVC | 1.4 (1.35–1.45) | — | — |
| PU / TPU | 1.2 (1.1–1.3) | — | — |
| PTFE — Teflon | 2.17 (2.14–2.2) | — | — |
| PEEK | 1.32 | — | High-temperature engineering plastic. |
| PEI — Ultem | 1.27 | — | — |
| PA12 | 1.02 | — | Also the powder used in laser sintering. |
| PLA | 1.24 | — | 3D printing. |
| PETG | 1.27 | — | 3D printing and thermoformed sheet. |
Composites and others
| Material | g/cm³ | Also called | Note |
|---|---|---|---|
| Glass fibre / epoxy | 1.9 (1.8–2.1) | — | Laminate. It depends on the fibre fraction. |
| G10 / FR4 | 1.85 | — | Pressed glass-fibre board. Insulation and jigs. |
| Carbon fibre / epoxy | 1.55 (1.5–1.6) | — | — |
| Compressed fibre gasket sheet | 1.4 | — | Gaskets and seals. |
| Plywood | 0.6 (0.45–0.75) | — | Packaging and jigs. The range is wide: it depends on the timber. |
Cast irons
| Material | g/cm³ | Also called | Note |
|---|---|---|---|
| Grey cast iron | 7.2 (7–7.3) | FC-200 · GG25 | — |
| Ductile cast iron | 7.1 (7–7.2) | FE-42012 · GGG40 | — |