DMLS 17-4PH Stainless Steel vs. Plastic Polypropylene

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

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

Plastic PolypropyleneBulk polymer (molded or machined)

Mechanical
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Yield strength	861MPasourcemean, as built, horizontal (N=72)	33MPasourcetypical, tensile stress at yield ISO 527
Ultimate tensile strength	886MPasourcemean, as built, horizontal (N=72)	not sourced
Elongation at break	19.9%sourcemean at break, as built, horizontal	not sourced
Young's modulus (stiffness)	197GPasourcebase material: wrought 17-4 PH, Condition H 900 (Cleveland-Cliffs)	1.45GPasourcetypical, tensile modulus ISO 527
Density	7,790kg/m³sourcemean part density (ISO 3369)	900kg/m³sourcetypical, 23 °C ISO 1183-1
Strength to weight	110kN·m/kg3.01x higher	36.7kN·m/kg
Stiffness to weight	25.3MN·m/kg15.7x higher	1.61MN·m/kg
Poisson's ratio	0.272sourcebase material: wrought 17-4 PH, all conditions (Cleveland-Cliffs)	0.42sourcebase material: polypropylene homopolymer family (INEOS Olefins & Polymers USA, Typical Engineering Properties of Polypropylene)
Shear modulus	77.4GPa152x stiffer in shear	0.511GPa
Bulk modulus	144GPa	3.02GPa
Speed of sound	5,029m/s	1,269m/s
Thermal
Thermal conductivity	17.9W/m·Ksourcebase material: wrought 17-4 PH, Condition H 900, at 149 °C (Cleveland-Cliffs)	0.17–0.22W/m·Ksourcebase material: polypropylene homopolymer family (INEOS Olefins & Polymers USA, Typical Engineering Properties of Polypropylene)
Thermal expansion	10.4µm/m·Ksourcemean 25-100 °C, ASTM E228, AFTER atmospheric heat treatment (as-built value not published)	80–100µm/m·Ksourcebase material: polypropylene homopolymer family (INEOS Olefins & Polymers USA, Typical Engineering Properties of Polypropylene)
100 mm part over a 50 °C swing	52µm growth8.65x less	450µm growth
Specific heat	460J/kg·Ksourcebase material: wrought 17-4 PH, Condition A, 0-100 °C (Cleveland-Cliffs)	not sourced
Heats up and cools (diffusivity)	5mm²/s	not sourced
Thermal shock resistance	5,474W/m191x more resistant	28.6W/m
Max service temperature	not sourced	90°CsourceHDT 0.45 MPa (ISO 75B), unannealed
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	LyondellBasell Moplen HP501H polypropylene homopolymer (general purpose), typical ISO 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 Polypropylene?

DMLS 17-4PH Stainless Steel is stronger: its yield strength is 861 MPa against 33 MPa for Plastic Polypropylene (26.1x).

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

Plastic Polypropylene is lighter: 900 kg/m³ against 7,790 kg/m³ for DMLS 17-4PH Stainless Steel.

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

DMLS 17-4PH Stainless Steel is stiffer: Young's modulus 197 GPa against 1.45 GPa for Plastic Polypropylene, 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 Polypropylene?

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, strong beam; Plastic Polypropylene is lighter for a stiff panel or plate, strong panel or plate.

Part that must be	DMLS 17-4PH Stainless Steel	Plastic Polypropylene
Stiff rod or tie (tension)	lighter	15.7x heavier
Stiff beam (bending)	lighter	35% heavier
Stiff panel or plate	1.68x heavier	lighter
Strong rod or tie	lighter	3.01x heavier
Strong beam	lighter	2% heavier
Strong panel or plate	1.69x 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 Polypropylene?

DMLS 17-4PH Stainless Steel conducts heat better: 17.9 W/m·K against 0.195 W/m·K for Plastic Polypropylene.

Which expands less with temperature?

DMLS 17-4PH Stainless Steel expands less: 10.4 µm/m·K against 90 µm/m·K for Plastic Polypropylene.

Among 59 materials

Stiffness against density

Strength against density