Material properties
Density, strength, stiffness, hardness and machinability for the materials that actually come across the scanner. Indicative values for design and estimation — confirm against the supplier certificate for load-bearing work.
| Material | Density g/cm³ | Yield MPa | Tensile MPa | E GPa | Hardness | Machinability | Typical use |
|---|---|---|---|---|---|---|---|
| Mild Steel A36 / S235 | 7.85 | 250 | 400–550 | 200 | ~120 HB | Excellent | Frames, brackets, weldments, jigs. |
| Steel 1045 / C45 | 7.85 | 310–450 | 570–700 | 205 | ~170 HB | Good | Shafts, gears, keys — heat-treatable. |
| Steel 4140 / 42CrMo4 | 7.85 | 655 | 850–1000 | 205 | 28–32 HRC (Q&T) | Fair | High-load shafts, couplings, tooling. |
| Tool Steel D2 | 7.70 | — | 1700–2000 | 210 | 58–62 HRC | Poor | Blanking dies, forming tools, wear parts. |
| Stainless 304 / 1.4301 | 7.93 | 215 | 505 | 193 | ~150 HB | Fair | Food, general corrosion resistance, enclosures. |
| Stainless 316L / 1.4404 | 7.99 | 170–220 | 485–620 | 193 | ~150 HB | Fair | Marine, chemical, pharma, medical. |
| Stainless 17-4 PH | 7.80 | 1100 (H900) | 1310 | 196 | 40–44 HRC | Fair | High-strength corrosion-resistant shafts, valve parts. |
| Aluminum 6061-T6 | 2.70 | 276 | 310 | 69 | 95 HB | Excellent | General machined parts, fixtures, structures. |
| Aluminum 7075-T6 | 2.81 | 503 | 572 | 72 | 150 HB | Good | Aerospace brackets, high-stress light parts. |
| Aluminum 5083 | 2.66 | 228 | 317 | 71 | ~75 HB | Fair | Marine plate, welded tanks. |
| Titanium Gr. 2 (CP) | 4.51 | 275 | 345 | 105 | ~160 HV | Fair | Corrosion-resistant fittings, heat exchangers. |
| Titanium Gr. 5 (Ti-6Al-4V) | 4.43 | 880 | 950 | 114 | ~350 HV | Poor | Aerospace, medical implants, high strength-to-weight. |
| Brass C360 | 8.50 | 310 | 470 | 97 | ~130 HB | Excellent | Fittings, valve bodies, high-volume turned parts. |
| Bronze C932 (SAE 660) | 8.93 | 125 | 240 | 100 | ~65 HB | Excellent | Plain bearings, bushings, wear strips. |
| Copper C110 | 8.96 | 70–330 | 220–390 | 117 | ~50 HB | Fair | Busbars, electrodes, thermal parts. |
| Grey Cast Iron GG25 | 7.20 | — | 250 | 110 | 180–220 HB | Excellent | Machine bases, housings — excellent damping. |
| Ductile Iron GGG40 | 7.10 | 250 | 400 | 169 | 140–200 HB | Good | Pump housings, crank arms, pipe fittings. |
| POM / Acetal (Delrin) | 1.41 | 70 | 70 | 3.1 | M94 Rockwell | Excellent | Gears, bushings, low-friction machined parts. |
| Nylon PA66 | 1.14 | 80 | 80 | 3.0 | M85 Rockwell | Good | Wear parts, rollers — note moisture absorption. |
| PEEK | 1.32 | 100 | 100 | 3.9 | M99 Rockwell | Good | High-temperature, chemical, medical-grade parts. |
| PTFE | 2.20 | 23 | 31 | 0.5 | Shore D55 | Fair | Seals, low-friction liners, chemical service. |
| ABS | 1.04 | 40 | 45 | 2.3 | R105 Rockwell | Good | Housings, prototypes, injection-moulded covers. |
| Nylon PA12 (SLS) | 1.01 | 48 | 48 | 1.7 | Shore D75 | Fair | Functional printed parts, jigs, low-volume production. |
| Carbon-filled Nylon (SLS) | 1.20 | 70 | 70 | 4.5 | Shore D80 | Fair | Stiff lightweight fixtures, drone and robotics parts. |
| Standard Resin (SLA) | 1.18 | 50 | 60 | 2.7 | Shore D80 | Poor | Visual prototypes, casting patterns — brittle and UV-sensitive. |
Identifying material from a scan
A scan gives you geometry, not metallurgy. The fastest practical route on a legacy part is to weigh it, take the watertight mesh volume, and divide: density alone separates aluminium (2.7), titanium (4.5), steel (7.85) and brass (8.5) without any lab work. From there, a hardness test tells you the heat-treat condition, and only load-critical parts justify a spectrometer or XRF reading.
Frequently asked
What is the density of steel and aluminium?
Carbon and alloy steels are about 7.85 g/cm³, stainless 304 is 7.93 g/cm³, and aluminium alloys sit near 2.70 g/cm³ — roughly one third the weight of steel for the same volume.
Is 6061 or 7075 aluminium stronger?
7075-T6 is much stronger: about 503 MPa yield versus 276 MPa for 6061-T6. 6061 is cheaper, weldable and more corrosion resistant, so it stays the default unless the part is strength-critical.
Which material should I pick when reverse engineering an unknown part?
Start with density from a mass-and-volume measurement — the scan gives you the volume and a scale gives you the mass. That narrows the family fast (aluminium vs steel vs brass vs plastic). Confirm with a hardness test and, when it matters structurally, XRF or a spectrometer reading.
Related on CADfinity
Turn a volume into mass and price instantly.
ISO 286 hole-basis calculator and IT grades.
ISO 273 holes, reamers, DIN 6885 keys.
Clamp load and yield percentage by grade.
The vocabulary of reverse engineering.
Send us the part — we'll send back the STEP.
