Engineering materials library

37 materials an engineer actually specifies, each with the property ranges that matter, what it is used for, and how it is processed and joined. Values are typical published ranges for orientation — confirm against the standard and the supplier datasheet before you commit.

Strength against density for 25 engineering materials A logarithmic property chart. Density runs from 0.8 to 12 grams per cubic centimetre on the horizontal axis and strength from 10 to 3000 megapascals on the vertical axis. Each material is drawn as a vertical capsule spanning its published strength range, coloured by material class. σ/ρ = 30 σ/ρ = 300 1 1.5 2 3 5 8 10 10 30 100 300 1000 3000 Density ρ (g/cm³) Strength σ (MPa) AISI 1045 carbon steel — ρ 7.85 g/cm³, tensile strength 565–850 MPa AISI 4140 (42CrMo4) — ρ 7.85 g/cm³, tensile strength 900–1200 MPa AISI 304 / 1.4301 stainless — ρ 7.9 g/cm³, tensile strength 515–720 MPa AISI 316L / 1.4404 stainless — ρ 8 g/cm³, tensile strength 485–620 MPa 17-4PH (1.4542) — ρ 7.75 g/cm³, tensile strength 930–1310 MPa Ductile iron EN-GJS-400-15 — ρ 7.1 g/cm³, tensile strength 400 MPa Aluminum 6061-T6 — ρ 2.7 g/cm³, tensile strength 310 MPa Aluminum 7075-T6 — ρ 2.81 g/cm³, tensile strength 572 MPa Ti-6Al-4V (Grade 5) — ρ 4.43 g/cm³, yield strength 830–1100 MPa Magnesium AZ31B — ρ 1.77 g/cm³, yield strength 150–220 MPa Copper Cu-ETP (C11000) — ρ 8.94 g/cm³, yield strength 70–330 MPa Cartridge brass C26000 (CuZn30) — ρ 8.53 g/cm³, tensile strength 300–900 MPa Bearing bronze C93200 (SAE 660) — ρ 8.9 g/cm³, tensile strength 240 MPa Monel 400 (NiCu30Fe) — ρ 8.8 g/cm³, yield strength 240–480 MPa Inconel 718 — ρ 8.19 g/cm³, yield strength 1030 MPa Hastelloy C-276 — ρ 8.89 g/cm³, yield strength 355 MPa Alumina Al₂O₃ (99.5 %) — ρ 3.9 g/cm³, compressive strength 2500 MPa Zirconia Y-TZP (3Y) — ρ 6.05 g/cm³, flexural strength 900–1200 MPa Silicon nitride Si₃N₄ — ρ 3.2 g/cm³, flexural strength 700–1000 MPa Polyamide PA66 (nylon) — ρ 1.14 g/cm³, tensile strength 80 MPa Polycarbonate (PC) — ρ 1.2 g/cm³, tensile strength 65 MPa PEEK — ρ 1.3 g/cm³, tensile strength 100 MPa PTFE (Teflon) — ρ 2.2 g/cm³, tensile strength 25 MPa CFRP (carbon/epoxy laminate) — ρ 1.55 g/cm³, tensile strength (0°) 1200–2000 MPa GFRP (glass/epoxy or polyester) — ρ 1.9 g/cm³, tensile strength 300–1100 MPa CFRP · best strength-to-weight Alumina Al₂O₃ · strongest Polyamide PA66 · lightest
Metals & Alloys (16) Ceramics & Glasses (3) Polymers & Elastomers (4) Composites (2) 25 of 37 library materials publish both a density and a strength. Bars span the published range; the dot is its midpoint.

37 of 37 materials shown

Steels & Irons · Medium-carbon steel

AISI 1045 carbon steel

General-purpose medium-carbon steel; good strength/toughness balance, responds to quench & temper.

Yield strength 310–530 MPa (norm./Q&T)
Tensile strength 565–850 MPa
Density 7.85 g/cm³
Steels & Irons · Low-alloy steel

AISI 4140 (42CrMo4)

Cr-Mo low-alloy steel with high hardenability and fatigue strength in the Q&T condition.

Yield strength 655–1000 MPa (Q&T)
Tensile strength 900–1200 MPa
Density 7.85 g/cm³
Steels & Irons · Austenitic stainless

AISI 304 / 1.4301 stainless

The workhorse 18/8 austenitic stainless; excellent corrosion resistance and formability, non-magnetic (annealed).

Yield strength ≥ 205 MPa
Tensile strength 515–720 MPa
Density 7.9 g/cm³
Steels & Irons · Austenitic stainless

AISI 316L / 1.4404 stainless

Mo-bearing austenitic stainless with improved pitting resistance (PREN ≈ 24); low-carbon variant for welding.

Yield strength ≥ 170 MPa
Tensile strength 485–620 MPa
PREN ~24
Steels & Irons · Precipitation-hardening stainless

17-4PH (1.4542)

Martensitic PH stainless combining ~1100 MPa strength with good corrosion resistance; properties set by aging (H900–H1150).

Yield strength 725–1170 MPa
Tensile strength 930–1310 MPa
Density 7.75 g/cm³
Steels & Irons · Cast iron

Ductile iron EN-GJS-400-15

Nodular (spheroidal graphite) cast iron; castable like grey iron but with steel-like ductility.

Tensile strength ≥ 400 MPa
Elongation ≥ 15 %
Density 7.1 g/cm³
Aluminum & Light Alloys · Al-Mg-Si (6xxx)

Aluminum 6061-T6

The most versatile heat-treatable aluminum alloy: good strength, corrosion resistance, weldability and extrudability.

Yield strength ~276 MPa
Tensile strength ~310 MPa
Density 2.70 g/cm³
Aluminum & Light Alloys · Al-Zn-Mg-Cu (7xxx)

Aluminum 7075-T6

Aerospace-grade high-strength aluminum approaching mild-steel strength at a third of the density.

Yield strength ~503 MPa
Tensile strength ~572 MPa
Density 2.81 g/cm³
Aluminum & Light Alloys · Titanium α+β

Ti-6Al-4V (Grade 5)

The standard titanium alloy: outstanding specific strength to ~350 °C and superb corrosion resistance; biocompatible.

Yield strength 830–1100 MPa
Density 4.43 g/cm³
E modulus 114 GPa
Aluminum & Light Alloys · Mg-Al-Zn

Magnesium AZ31B

Wrought magnesium alloy — the lightest structural metal in common use; excellent damping and machinability.

Yield strength 150–220 MPa
Density 1.77 g/cm³
E modulus 45 GPa
Copper & Nickel Alloys · Pure copper

Copper Cu-ETP (C11000)

Electrolytic tough-pitch copper — the standard electrical conductor (≥ 100 % IACS).

Conductivity ≥ 100 % IACS
Yield strength 70–330 MPa (temper)
Density 8.94 g/cm³
Copper & Nickel Alloys · Brass

Cartridge brass C26000 (CuZn30)

70/30 brass with the best combination of strength and cold formability among brasses.

Tensile strength 300–900 MPa (temper)
Density 8.53 g/cm³
Elongation up to 65 %
Copper & Nickel Alloys · Bronze

Bearing bronze C93200 (SAE 660)

Leaded tin bronze — the standard general-purpose bearing material against steel shafts.

Tensile strength ~240 MPa
Hardness ~65 HB
Density 8.9 g/cm³
Copper & Nickel Alloys · Ni-Cu alloy

Monel 400 (NiCu30Fe)

Ni-Cu solid-solution alloy with outstanding seawater, HF and alkali resistance.

Yield strength 240–480 MPa
Density 8.8 g/cm³
Max service temp ~540 °C
Superalloys & Refractory · Ni-base superalloy

Inconel 718

γ''-strengthened Ni superalloy, the aerospace standard to ~650 °C; good weldability for a superalloy.

Yield strength ~1030 MPa (aged)
Max service temp ~650 °C
Density 8.19 g/cm³
Superalloys & Refractory · Ni-Mo-Cr alloy

Hastelloy C-276

Ni-Mo-Cr-W alloy with near-universal resistance to hot acids and chlorides; benchmark for severe chemical service.

Yield strength ~355 MPa
Density 8.89 g/cm³
PREN >70
Superalloys & Refractory · Refractory metal

Tungsten (pure)

Highest melting point of all metals (3422 °C); extreme density and stiffness, brittle below its DBTT.

Melting point 3422 °C
Density 19.25 g/cm³
E modulus 411 GPa
Ceramics & Glasses · Oxide ceramic

Alumina Al₂O₃ (99.5 %)

The most widely used technical ceramic: hard, chemically inert, excellent electrical insulator.

Hardness ~18 GPa (HV)
Compressive strength ~2500 MPa
Max service temp ~1650 °C
Ceramics & Glasses · Oxide ceramic

Zirconia Y-TZP (3Y)

Transformation-toughened zirconia — the toughest oxide ceramic ('ceramic steel').

Fracture toughness 5–10 MPa·√m
Flexural strength 900–1200 MPa
Density 6.05 g/cm³
Ceramics & Glasses · Non-oxide ceramic

Silicon carbide (SSiC)

Extremely hard, stiff, thermally conductive ceramic stable to very high temperature; also a wide-bandgap semiconductor.

Hardness ~25 GPa
Thermal conductivity 100–150 W/m·K
Max service temp ~1600 °C
Ceramics & Glasses · Non-oxide ceramic

Silicon nitride Si₃N₄

Best thermal-shock resistance among major ceramics; high toughness for a ceramic — the bearing-ball material.

Fracture toughness 5–8 MPa·√m
Flexural strength 700–1000 MPa
Density 3.2 g/cm³
Ceramics & Glasses · Glass

Fused silica (SiO₂ glass)

Near-zero thermal expansion glass with excellent UV transmission and thermal-shock immunity.

CTE 0.55 ppm/K
Max service temp ~1100 °C
Transmission UV–IR
Polymers · Engineering thermoplastic

Polyamide PA66 (nylon)

Tough, wear-resistant workhorse engineering polymer; properties drop notably with moisture uptake.

Tensile strength ~80 MPa (dry)
Max service temp ~120 °C (cont.)
Density 1.14 g/cm³
Polymers · Engineering thermoplastic

Polycarbonate (PC)

Transparent thermoplastic with outstanding impact strength; sensitive to solvents and UV (grade-dependent).

Impact (notched Izod) 600–850 J/m
Tensile strength ~65 MPa
Max service temp ~115 °C
Polymers · High-performance thermoplastic

PEEK

Semi-crystalline high-performance polymer: 250 °C continuous service, superb chemical resistance, sterilizable.

Tensile strength ~100 MPa
Max service temp 250 °C (cont.)
Density 1.30 g/cm³
Polymers · Fluoropolymer

PTFE (Teflon)

Lowest friction coefficient of any solid and near-total chemical inertness; soft and creep-prone.

Friction coeff. 0.05–0.10
Service temp -200 to +260 °C
Density 2.2 g/cm³
Polymers · Polyolefin

UHMW-PE

Ultra-high molecular weight polyethylene: extreme abrasion resistance and impact toughness, self-lubricating.

Abrasion resistance outstanding
Impact strength no break
Max service temp ~80 °C
Elastomers · Oil-resistant elastomer

Nitrile rubber (NBR)

The default seal material for oils and fuels; limited weather/ozone resistance.

Hardness 40–90 Shore A
Service temp -30 to +100 °C
Oil resistance excellent
Elastomers · Weather-resistant elastomer

EPDM

Outstanding ozone, UV, steam and water resistance; poor with oils and fuels.

Hardness 30–90 Shore A
Service temp -50 to +150 °C
Weathering excellent
Elastomers · High-temp elastomer

Silicone rubber (VMQ)

Widest service-temperature range of common elastomers; biocompatible; modest strength and tear resistance.

Service temp -60 to +230 °C
Hardness 10–80 Shore A
Tear strength low–moderate
Composites · Polymer-matrix composite

CFRP (carbon/epoxy laminate)

The benchmark high-performance structural composite: steel-level strength at ~20 % of the density (in-plane, fiber direction).

Tensile strength (0°) 1200–2000 MPa
E (0°) 70–150 GPa
Density 1.55 g/cm³
Composites · Polymer-matrix composite

GFRP (glass/epoxy or polyester)

Cost-effective composite with good strength, corrosion resistance and electrical transparency.

Tensile strength 300–1100 MPa (layup)
Density 1.8–2.0 g/cm³
Cost ~10× cheaper than CFRP
Composites · Metal-matrix composite

Al-SiC metal-matrix composite

Aluminum reinforced with SiC particles: higher stiffness and wear resistance, tailored CTE for electronics.

E modulus 100–200 GPa
CTE 7–12 ppm/K (tunable)
Density 2.9–3.0 g/cm³
Semiconductors & Functional · Elemental semiconductor

Monocrystalline silicon

The foundation of microelectronics and photovoltaics; indirect gap 1.12 eV.

Band gap 1.12 eV (indirect)
E modulus 130–188 GPa (anisotropic)
Density 2.33 g/cm³
Semiconductors & Functional · Wide-bandgap semiconductor

Gallium nitride (GaN)

Wide-bandgap (3.4 eV) semiconductor enabling blue LEDs and high-frequency, high-power electronics.

Band gap 3.4 eV (direct)
Breakdown field ~3.3 MV/cm
Structure wurtzite
Semiconductors & Functional · Piezoelectric ceramic

PZT (lead zirconate titanate)

The dominant piezoelectric ceramic (perovskite); converts electrical ↔ mechanical energy with high coupling.

d₃₃ 300–600 pC/N
Curie temp ~200–350 °C
Structure perovskite ABO₃
Semiconductors & Functional · Hard magnetic material

NdFeB (N42–N52)

The strongest permanent magnet family; tetragonal Nd₂Fe₁₄B phase. Temperature-sensitive; Dy additions improve coercivity.

(BH)max up to ~52 MGOe
Max service temp 80–200 °C (grade)
Density 7.5 g/cm³

By material class

Each category rolls up into one of the 5 broad classes, where bonding — not application — is what separates them.

Narrowing 37 down to one

Describe the load case, the environment and the budget, and the material selector returns a ranked shortlist with the trade-offs spelled out.