DMLS 17-4PH Stainless Steel vs. Plastic Nylon PA66

Compare DMLS 17-4PH Stainless Steel vs. Plastic Nylon PA66 strength, stiffness, weight and thermal properties.

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

Plastic Nylon PA66Bulk polymer (molded or machined)

Mechanical
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Yield strength	861MPasourcemean, as built, horizontal (N=72)	85MPasourcetypical, dry
Ultimate tensile strength	886MPasourcemean, as built, horizontal (N=72)	not sourced
Elongation at break	19.9%sourcemean at break, as built, horizontal	30%sourcenominal strain at break, dry
Young's modulus (stiffness)	197GPasourcebase material: wrought 17-4 PH, Condition H 900 (Cleveland-Cliffs)	3GPasourcetypical, dry
Density	7,790kg/m³sourcemean part density (ISO 3369)	1,130kg/m³sourcetypical
Strength to weight	110kN·m/kg47% higher	75.2kN·m/kg
Stiffness to weight	25.3MN·m/kg9.53x higher	2.65MN·m/kg
Poisson's ratio	0.272sourcebase material: wrought 17-4 PH, all conditions (Cleveland-Cliffs)	0.4sourcebase material: unfilled polyamide (PA), conditioned, maker design-guide family value (Covestro Table 3-1)
Shear modulus	77.4GPa72.3x stiffer in shear	1.07GPa
Bulk modulus	144GPa	5GPa
Speed of sound	5,029m/s	1,629m/s
Thermal
Thermal conductivity	17.9W/m·Ksourcebase material: wrought 17-4 PH, Condition H 900, at 149 °C (Cleveland-Cliffs)	0.33W/m·Ksourcetypical
Thermal expansion	10.4µm/m·Ksourcemean 25-100 °C, ASTM E228, AFTER atmospheric heat treatment (as-built value not published)	98µm/m·Ksourcelongitudinal, 23-55 °C
100 mm part over a 50 °C swing	52µm growth9.42x less	490µm growth
Specific heat	460J/kg·Ksourcebase material: wrought 17-4 PH, Condition A, 0-100 °C (Cleveland-Cliffs)	1,700J/kg·Ksourcetypical
Heats up and cools (diffusivity)	5mm²/s29.1x faster	0.172mm²/s
Thermal shock resistance	5,474W/m95.6x more resistant	57.2W/m
Melting point	not sourced	260°CsourceDSC
Max service temperature	not sourced	101°CsourceIEC 60216 temperature index, 20000 h
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	BASF Ultramid A3K (PA66, unreinforced injection-moulding grade), Product Information 02/2026, dry values (ISO methods)

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 Nylon PA66?

DMLS 17-4PH Stainless Steel is stronger: its yield strength is 861 MPa against 85 MPa for Plastic Nylon PA66 (10.1x).

Which is lighter, DMLS 17-4PH Stainless Steel or Plastic Nylon PA66?

Plastic Nylon PA66 is lighter: 1,130 kg/m³ against 7,790 kg/m³ for DMLS 17-4PH Stainless Steel.

Which is stiffer, DMLS 17-4PH Stainless Steel or Plastic Nylon PA66?

DMLS 17-4PH Stainless Steel is stiffer: Young's modulus 197 GPa against 3 GPa for Plastic Nylon PA66, 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 Nylon PA66?

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 Nylon PA66 is lighter for a stiff panel or plate, strong beam, strong panel or plate.

Part that must be	DMLS 17-4PH Stainless Steel	Plastic Nylon PA66
Stiff rod or tie (tension)	lighter	9.53x heavier
Stiff beam (bending)	lighter	18% heavier
Stiff panel or plate	1.71x heavier	lighter
Strong rod or tie	lighter	47% heavier
Strong beam	47% heavier	lighter
Strong panel or plate	2.17x 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 Nylon PA66?

DMLS 17-4PH Stainless Steel conducts heat better: 17.9 W/m·K against 0.33 W/m·K for Plastic Nylon PA66.

Which expands less with temperature?

DMLS 17-4PH Stainless Steel expands less: 10.4 µm/m·K against 98 µm/m·K for Plastic Nylon PA66.

Among 59 materials

Stiffness against density

Strength against density