Plastic Polypropylene vs. SLS PA12 Nylon

Compare Plastic Polypropylene vs. SLS PA12 Nylon strength, stiffness, weight and thermal properties.

Plastic PolypropyleneBulk polymer (molded or machined)

Mechanical	Plastic Polypropylene	SLS PA12 Nylon
Yield strength	33MPa1	not given (tensile used)
Ultimate tensile strength	not stated (yield given)	48MPa2
Elongation at break	not sourced	18%2
Young's modulus (stiffness)	1.45GPa1	1.65GPa214% stiffer
Density	900kg/m³1	930kg/m³2
Strength to weight	36.7kN·m/kg	51.6kN·m/kg41% higher
Stiffness to weight	1.61MN·m/kg	1.77MN·m/kg10% higher
Poisson's ratio	base material0.423	not sourced
Shear modulus	0.511GPa	not sourced
Bulk modulus	3.02GPa	not sourced
Speed of sound	1,269m/s	1,332m/s5% faster

Stiffness against densityHigher and further left: stiffer for its weight

Strength against densityHigher and further left: stronger for its weight

Thermal	Plastic Polypropylene	SLS PA12 Nylon
Thermal conductivity	base material0.17–0.22W/m·K3	not sourced
Thermal expansion	base material80–100µm/m·K3	not sourced
100 mm part over a 50 °C swing	450µm growth	not sourced
Specific heat	not sourced	not sourced
Heats up and cools (diffusivity)	not sourced	not sourced
Thermal shock resistance	28.6W/m	not sourced
Melting point	not sourced	176°C2
Max service temperature	HDT 0.45 MPa90°C1	HDT 1.8 MPa64°C2

Thermal conductivity against densityHigher and further left: spreads more heat for its weight

Thermal expansion against thermal conductivityLower and further right: warps less when heated

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Sources3 documents: LyondellBasell, EOS GmbH, INEOS Olefins & Polymers USA

Plastic Polypropylene: LyondellBasell Moplen HP501H polypropylene homopolymer (general purpose), typical ISO values
SLS PA12 Nylon: EOS PA 2200 (PA12) Material Data Sheet, process parameter 'Balance' at 120 µm layer thickness, X orientation, dry (conditioned values not given). Live MDS status 04.10.2026, last changed 10.09.2026; PDF via ?topdf=... link on the same page.

1
Moplen HP501H Product DataLyondellBasellPlastic Polypropylene · Yield strength: typical, tensile stress at yield ISO 527Plastic Polypropylene · Young's modulus (stiffness): typical, tensile modulus ISO 527Plastic Polypropylene · Density: typical, 23 °C ISO 1183-1Plastic Polypropylene · Max service temperature: HDT 0.45 MPa (ISO 75B), unannealed
2
PA 2200 Balance Material Data SheetEOS GmbHSLS PA12 Nylon · Ultimate tensile strength: typicalSLS PA12 Nylon · Elongation at break: typicalSLS PA12 Nylon · Young's modulus (stiffness): typicalSLS PA12 Nylon · Density: typicalSLS PA12 Nylon · Melting point: typicalSLS PA12 Nylon · Max service temperature: HDT 1.8 MPa, X orientation
3
Typical Engineering Properties of PolypropyleneINEOS Olefins & Polymers USAarchived copyPlastic Polypropylene · Poisson's ratio: base material: polypropylene homopolymer family (INEOS Olefins & Polymers USA, Typical Engineering Properties of Polypropylene)Plastic Polypropylene · Thermal conductivity: base material: polypropylene homopolymer family (INEOS Olefins & Polymers USA, Typical Engineering Properties of Polypropylene)Plastic Polypropylene · Thermal expansion: base material: polypropylene homopolymer family (INEOS Olefins & Polymers USA, Typical Engineering Properties of Polypropylene)

Each number points to the document that states it, with the exact basis. Values without a number are computed from the sourced ones. "Not sourced" means no citable source states it (or only a specification minimum); figures computed from it are left out too.

SLS PA12 Nylon is 3D printed: its properties depend on build direction and print settings; these are typical values.

Questions

Mechanical

Is Plastic Polypropylene stronger than SLS PA12 Nylon?

SLS PA12 Nylon is stronger: its tensile strength is 48 MPa against yield strength 33 MPa for Plastic Polypropylene (45%).

Which is lighter, Plastic Polypropylene or SLS PA12 Nylon?

Plastic Polypropylene is lighter: 900 kg/m³ against 930 kg/m³ for SLS PA12 Nylon.

Which is stiffer, Plastic Polypropylene or SLS PA12 Nylon?

SLS PA12 Nylon is stiffer: Young's modulus 1.65 GPa against 1.45 GPa for Plastic Polypropylene, so the same part in SLS PA12 Nylon deflects less under the same load.

Which is lighter for the same job, Plastic Polypropylene or SLS PA12 Nylon?

For the same stiffness or strength: SLS PA12 Nylon is lighter for a stiff rod or tie (tension), stiff beam (bending), stiff panel or plate, strong rod or tie, strong beam, strong panel or plate.

Part that must be	Plastic Polypropylene	SLS PA12 Nylon
Stiff rod or tie (tension)	10% heavier	lighter
Stiff beam (bending)	3% heavier	lighter
Stiff panel or plate	1% heavier	lighter
Strong rod or tie	41% heavier	lighter
Strong beam	24% heavier	lighter
Strong panel or plate	17% 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).