DMLS 17-4PH Stainless Steel vs. Plastic Polycarbonate

Compare DMLS 17-4PH Stainless Steel vs. Plastic Polycarbonate strength, stiffness, weight and thermal properties.

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DMLS 17-4PH Stainless Steel3D printed metal (DMLS)

Plastic PolycarbonateBulk polymer (molded or machined)

Mechanical
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Yield strength	861MPasourcemean, as built, horizontal (N=72)	65MPasourcetypical, tensile yield
Ultimate tensile strength	886MPasourcemean, as built, horizontal (N=72)	65MPasourcetypical, stress at break
Flexural strength	not sourced	97MPasourcetypical, flexural strength
Elongation at break	19.9%sourcemean at break, as built, horizontal	125%sourcetypical, strain at break
Young's modulus (stiffness)	197GPasourcebase material: wrought 17-4 PH, Condition H 900 (Cleveland-Cliffs)	2.4GPasourcetypical
Density	7,790kg/m³sourcemean part density (ISO 3369)	1,200kg/m³sourcetypical
Strength to weight	110kN·m/kg2.04x higher	54.2kN·m/kg
Stiffness to weight	25.3MN·m/kg12.6x higher	2MN·m/kg
Poisson's ratio	0.272sourcebase material: wrought 17-4 PH, all conditions (Cleveland-Cliffs)	0.38sourcetypical, polycarbonate family (Covestro Part and Mold Design guide, Table 3-1)
Shear modulus	77.4GPa89.1x stiffer in shear	0.87GPa
Bulk modulus	144GPa	3.33GPa
Speed of sound	5,029m/s	1,414m/s
Thermal
Thermal conductivity	17.9W/m·Ksourcebase material: wrought 17-4 PH, Condition H 900, at 149 °C (Cleveland-Cliffs)	0.2W/m·Ksourcetypical, through-plane, 23 C
Thermal expansion	10.4µm/m·Ksourcemean 25-100 °C, ASTM E228, AFTER atmospheric heat treatment (as-built value not published)	65µm/m·Ksourcetypical, 23-55 C, parallel and normal
100 mm part over a 50 °C swing	52µm growth6.25x less	325µm growth
Specific heat	460J/kg·Ksourcebase material: wrought 17-4 PH, Condition A, 0-100 °C (Cleveland-Cliffs)	1,172J/kg·Ksourcetypical (guide value), Bayer ASTM datasheet for Makrolon 2405, ASTM D 2766
Heats up and cools (diffusivity)	5mm²/s35.1x faster	0.142mm²/s
Thermal shock resistance	5,474W/m106x more resistant	51.7W/m
Glass transition	not sourced	144°Csourcetypical, DSC 10 C/min
Max service temperature	not sourced	125°CsourceUL 746B RTI, tensile strength, 1.5 mm
Values for	EOS StainlessSteel 17-4PH IndustryLine (powder 9011-0041), EOS M 290, 40 µm, default job 17-4PH_040_StainlessM291_100, as built, horizontal; ISO 6892 & ASTM E8M	Covestro Makrolon 2405 general-purpose PC (MVR 19), Covestro technical datasheet version 2026-09-28, typical values

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.

DMLS 17-4PH Stainless Steel is 3D printed: its properties depend on build direction and print settings; these are typical values.

Questions

Is DMLS 17-4PH Stainless Steel stronger than Plastic Polycarbonate?

DMLS 17-4PH Stainless Steel is stronger: its yield strength is 861 MPa against 65 MPa for Plastic Polycarbonate (13.2x).

Which is lighter, DMLS 17-4PH Stainless Steel or Plastic Polycarbonate?

Plastic Polycarbonate is lighter: 1,200 kg/m³ against 7,790 kg/m³ for DMLS 17-4PH Stainless Steel.

Which is stiffer, DMLS 17-4PH Stainless Steel or Plastic Polycarbonate?

DMLS 17-4PH Stainless Steel is stiffer: Young's modulus 197 GPa against 2.4 GPa for Plastic Polycarbonate, so the same part in DMLS 17-4PH Stainless Steel deflects less under the same load.

Which is lighter for the same job, DMLS 17-4PH Stainless Steel or Plastic Polycarbonate?

For the same stiffness or strength: DMLS 17-4PH Stainless Steel is lighter for a stiff rod or tie (tension), stiff beam (bending), strong rod or tie; Plastic Polycarbonate is lighter for a stiff panel or plate, strong beam, strong panel or plate.

Part that must be	DMLS 17-4PH Stainless Steel	Plastic Polycarbonate
Stiff rod or tie (tension)	lighter	12.6x heavier
Stiff beam (bending)	lighter	40% heavier
Stiff panel or plate	49% heavier	lighter
Strong rod or tie	lighter	2.04x heavier
Strong beam	16% heavier	lighter
Strong panel or plate	1.78x heavier	lighter

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, DMLS 17-4PH Stainless Steel or Plastic Polycarbonate?

DMLS 17-4PH Stainless Steel conducts heat better: 17.9 W/m·K against 0.2 W/m·K for Plastic Polycarbonate.

Which expands less with temperature?

DMLS 17-4PH Stainless Steel expands less: 10.4 µm/m·K against 65 µm/m·K for Plastic Polycarbonate.

Among 59 materials

Stiffness against density

Strength against density