Plastic Nylon vs. Plastic Polypropylene

Compare Plastic Nylon vs. Plastic Polypropylene strength, stiffness, weight and thermal properties.

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Plastic PolypropyleneBulk 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	63.1MPasourcetypical	33MPasourcetypical, tensile stress at yield ISO 527
Ultimate tensile strength	63.1MPasourcetypical, peak stress (= stress at yield)	not sourced
Flexural strength	82.9MPasourcetypical	not sourced
Elongation at break	not sourced	not sourced
Young's modulus (stiffness)	2.33GPasourcetypical	1.45GPasourcetypical, tensile modulus ISO 527
Density	1,140kg/m³sourcetypical	900kg/m³sourcetypical, 23 °C ISO 1183-1
Strength to weight	55.4kN·m/kg1.51x higher	36.7kN·m/kg
Stiffness to weight	2.04MN·m/kg27% higher	1.61MN·m/kg
Poisson's ratio	0.4sourcebase material: unfilled polyamide (PA), conditioned, maker design-guide family value (Covestro Table 3-1)	0.42sourcebase material: polypropylene homopolymer family (INEOS Olefins & Polymers USA, Typical Engineering Properties of Polypropylene)
Shear modulus	0.833GPa1.63x stiffer in shear	0.511GPa
Bulk modulus	3.89GPa	3.02GPa
Speed of sound	1,430m/s	1,269m/s
Thermal
Thermal conductivity	0.33W/m·Ksourcebase material: unreinforced BASF Ultramid PA66 (A3K) and PA6 (B3S), 23 C (same value for both)	0.17–0.22W/m·Ksourcebase material: polypropylene homopolymer family (INEOS Olefins & Polymers USA, Typical Engineering Properties of Polypropylene)
Thermal expansion	98–102µm/m·Ksourcebase material: unreinforced BASF Ultramid PA66 (A3K, 98) and PA6 (B3S, 102), 23-55 C	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	500µm growth	450µm growth11% less
Specific heat	1,700J/kg·Ksourcebase material: unreinforced BASF Ultramid PA66 (A3K) and PA6 (B3S), 23 C (same value for both)	not sourced
Heats up and cools (diffusivity)	0.17mm²/s	not sourced
Thermal shock resistance	53.6W/m1.87x more resistant	28.6W/m
Melting point	188°Csourcetypical	not sourced
Glass transition	55.1°Csourcetypical	not sourced
Max service temperature	89.2°CsourceHDT 0.455 MPa (printed specimens)	90°CsourceHDT 0.45 MPa (ISO 75B), unannealed
Values for	Ultimaker Nylon, 3D-printed specimens, XY (flat), conditioned >=24 h at room temperature; Ultimaker S5 Pro, engineering intent profile, 0.15 mm layer height, AA 0.4 print core, 100% infill, Cura 4.9, printed one-at-a-time, conditioned >=24 h at room temperature. TDS v2.00, April 20, 2022.	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.

Plastic Nylon is 3D printed: its properties depend on build direction and print settings; these are typical values.

Questions

Is Plastic Nylon stronger than Plastic Polypropylene?

Plastic Nylon is stronger: its yield strength is 63.1 MPa against 33 MPa for Plastic Polypropylene (1.91x).

Which is lighter, Plastic Nylon or Plastic Polypropylene?

Plastic Polypropylene is lighter: 900 kg/m³ against 1,140 kg/m³ for Plastic Nylon.

Which is stiffer, Plastic Nylon or Plastic Polypropylene?

Plastic Nylon is stiffer: Young's modulus 2.33 GPa against 1.45 GPa for Plastic Polypropylene, so the same part in Plastic Nylon deflects less under the same load.

Which is lighter for the same job, Plastic Nylon or Plastic Polypropylene?

For the same stiffness or strength: Plastic Nylon is lighter for a stiff rod or tie (tension), strong rod or tie, strong beam, strong panel or plate; Plastic Polypropylene is lighter for a stiff panel or plate.

Part that must be	Plastic Nylon	Plastic Polypropylene
Stiff rod or tie (tension)	lighter	27% heavier
Stiff beam (bending)	about equal	about equal
Stiff panel or plate	8% heavier	lighter
Strong rod or tie	lighter	1.51x heavier
Strong beam	lighter	22% heavier
Strong panel or plate	lighter	9% 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 Nylon or Plastic Polypropylene?

Plastic Nylon conducts heat better: 0.33 W/m·K against 0.195 W/m·K for Plastic Polypropylene.

Which expands less with temperature?

Plastic Polypropylene expands less: 90 µm/m·K against 100 µm/m·K for Plastic Nylon.

Among 59 materials

Stiffness against density

Strength against density