Plastic ABS (bulk/injection) vs. Steel AISI 1045

Compare Plastic ABS (bulk/injection) vs. Steel AISI 1045 strength, stiffness, weight and thermal properties.

Change either side

Plastic ABS (bulk/injection)Bulk polymer (molded or machined)

Mechanical
Try it on a partA bracket to run stress or thermal on, free in your browser	Open in LessCAD	Open in LessCAD
Yield strength	45MPasourcetypical, tensile stress at yield 23 °C	531MPasourceproducer-stated, cold drawn
Ultimate tensile strength	not sourced	627MPasourceproducer-stated, cold drawn
Flexural strength	65MPasourcetypical, 23 °C	not sourced
Elongation at break	10%sourcenominal strain at break, 23 °C	12%sourcein 2 in (50.8 mm)
Young's modulus (stiffness)	2.3GPasourcetypical	210GPasourcetypical91.3x stiffer
Density	1,040kg/m³sourcetypical7.5x lighter	7,800kg/m³sourcetypical
Strength to weight	43.3kN·m/kg	68.1kN·m/kg1.57x higher
Stiffness to weight	2.21MN·m/kg	26.9MN·m/kg12.2x higher
Poisson's ratio	0.39sourcetypical, ABS family (Covestro Part and Mold Design guide, Table 3-1)	0.3sourcetypical
Shear modulus	0.827GPa	80.8GPa97.6x stiffer in shear
Bulk modulus	3.48GPa	175GPa
Speed of sound	1,487m/s	5,189m/s
Thermal
Thermal conductivity	0.17W/m·Ksourcetypical	40–45W/m·Ksourcetypical range, ambient
Thermal expansion	80–110µm/m·Ksourcerange	12µm/m·Ksourcetypical, mean 20-300 °C
100 mm part over a 50 °C swing	475µm growth	60µm growth7.92x less
Specific heat	not sourced	460–480J/kg·Ksourcetypical range, 50/100 °C
Heats up and cools (diffusivity)	not sourced	11.6mm²/s
Thermal shock resistance	21.4W/m	6,269W/m294x more resistant
Max service temperature	94°CsourceHDT 1.8 MPa (annealed 4 h/80 °C)	not sourced
Values for	INEOS Styrolution Terluran GP-22 general-purpose injection-molding ABS, ISO typical values (TDS revision 08/01/2022)	AISI 1045 cold drawn bar (Niagara LaSalle) for mechanical; Ovako C45 (lists 'SAE 1045' as a similar designation) for physical constants

Every value links to the document that states it. "Not sourced" means no citable source states it (or only a specification minimum); figures computed from it are left out too.

Questions

Is Plastic ABS (bulk/injection) stronger than Steel AISI 1045?

Steel AISI 1045 is stronger: its yield strength is 531 MPa against 45 MPa for Plastic ABS (bulk/injection) (11.8x).

Which is lighter, Plastic ABS (bulk/injection) or Steel AISI 1045?

Plastic ABS (bulk/injection) is lighter: 1,040 kg/m³ against 7,800 kg/m³ for Steel AISI 1045.

Which is stiffer, Plastic ABS (bulk/injection) or Steel AISI 1045?

Steel AISI 1045 is stiffer: Young's modulus 210 GPa against 2.3 GPa for Plastic ABS (bulk/injection), so the same part in Steel AISI 1045 deflects less under the same load.

Which is lighter for the same job, Plastic ABS (bulk/injection) or Steel AISI 1045?

For the same stiffness or strength: Plastic ABS (bulk/injection) is lighter for a stiff panel or plate, strong beam, strong panel or plate; Steel AISI 1045 is lighter for a stiff rod or tie (tension), stiff beam (bending), strong rod or tie.

Part that must be	Plastic ABS (bulk/injection)	Steel AISI 1045
Stiff rod or tie (tension)	12.2x heavier	lighter
Stiff beam (bending)	27% heavier	lighter
Stiff panel or plate	lighter	1.67x heavier
Strong rod or tie	1.57x heavier	lighter
Strong beam	lighter	45% heavier
Strong panel or plate	lighter	2.18x heavier

For the same stiffness or strength, mass scales with density over stiffness (or strength) raised to a power set by how the part is loaded: 1 for a rod in tension, 1/2 for a beam in bending, 1/3 for a panel (the standard material-selection indices).

Which conducts heat better, Plastic ABS (bulk/injection) or Steel AISI 1045?

Steel AISI 1045 conducts heat better: 42.5 W/m·K against 0.17 W/m·K for Plastic ABS (bulk/injection).

Which expands less with temperature?

Steel AISI 1045 expands less: 12 µm/m·K against 95 µm/m·K for Plastic ABS (bulk/injection).

Among 59 materials

Stiffness against density

Strength against density