Plastic PLA vs. SLS PA12 Nylon

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

Mechanical	Plastic PLA	SLS PA12 Nylon
Yield strength	52.5MPa1	not given (tensile used)
Ultimate tensile strength	52.5MPa1	48MPa2
Flexural strength	96.8MPa1	not sourced
Elongation at break	7.8%1	18%22.31x more ductile
Young's modulus (stiffness)	3.25GPa11.97x stiffer	1.65GPa2
Density	1,240kg/m³1	930kg/m³233% lighter
Strength to weight	42.3kN·m/kg	51.6kN·m/kg22% higher
Stiffness to weight	2.62MN·m/kg48% higher	1.77MN·m/kg
Poisson's ratio	not sourced	not sourced
Shear modulus	not sourced	not sourced
Bulk modulus	not sourced	not sourced
Speed of sound	1,619m/s22% faster	1,332m/s

Stiffness against densityHigher and further left: stiffer for its weight

Strength against densityHigher and further left: stronger for its weight

Thermal	Plastic PLA	SLS PA12 Nylon
Thermal conductivity	base material0.13W/m·K3	not sourced
Thermal expansion	not sourced	not sourced
100 mm part over a 50 °C swing	not sourced	not sourced
Specific heat	base material1,200J/kg·K3	not sourced
Heats up and cools (diffusivity)	0.0874mm²/s	not sourced
Thermal shock resistance	not sourced	not sourced
Melting point	152°C1	176°C224.2 °C higher
Glass transition	59.1°C1	not sourced
Max service temperature	HDT 0.455 MPa58.8°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: UltiMaker, EOS GmbH, NatureWorks

Plastic PLA: Ultimaker PLA, 3D-printed specimens, XY (flat) orientation; 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 dated April 20, 2022.
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
Ultimaker PLA Technical Data Sheet, v5.00UltiMakerarchived copyPlastic PLA · Yield strength: typicalPlastic PLA · Ultimate tensile strength: typical, peak stress (= stress at yield)Plastic PLA · Flexural strength: typicalPlastic PLA · Elongation at break: typicalPlastic PLA · Young's modulus (stiffness): typicalPlastic PLA · Density: typicalPlastic PLA · Melting point: typicalPlastic PLA · Glass transition: typicalPlastic PLA · Max service temperature: HDT 0.455 MPa (printed specimens)
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
Engineering Properties of Ingeo BiopolymerNatureWorksarchived copyPlastic PLA · Thermal conductivity: base material: NatureWorks Ingeo biopolymer, amorphous sheet, 25 °CPlastic PLA · Specific heat: base material: NatureWorks Ingeo biopolymer, amorphous sheet, 25 °C

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.

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

Questions

Mechanical

Is Plastic PLA stronger than SLS PA12 Nylon?

Plastic PLA is stronger: its yield strength is 52.5 MPa against tensile strength 48 MPa for SLS PA12 Nylon (9%).

Which is lighter, Plastic PLA or SLS PA12 Nylon?

SLS PA12 Nylon is lighter: 930 kg/m³ against 1,240 kg/m³ for Plastic PLA.

Which is stiffer, Plastic PLA or SLS PA12 Nylon?

Plastic PLA is stiffer: Young's modulus 3.25 GPa against 1.65 GPa for SLS PA12 Nylon, so the same part in Plastic PLA deflects less under the same load.

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

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

Part that must be	Plastic PLA	SLS PA12 Nylon
Stiff rod or tie (tension)	lighter	48% heavier
Stiff beam (bending)	lighter	5% heavier
Stiff panel or plate	6% heavier	lighter
Strong rod or tie	22% heavier	lighter
Strong beam	26% heavier	lighter
Strong panel or plate	27% 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 is more ductile, Plastic PLA or SLS PA12 Nylon?

SLS PA12 Nylon stretches further before it breaks: 18% elongation at break against 7.8% for Plastic PLA.