Plastic Nylon PA66 vs. SLS PA12 Nylon

Compare Plastic Nylon PA66 vs. SLS PA12 Nylon strength, stiffness, weight and thermal properties.

Plastic Nylon PA66Bulk polymer (molded or machined)

Mechanical	Plastic Nylon PA66	SLS PA12 Nylon
Yield strength	85MPa1	not given (tensile used)
Ultimate tensile strength	not stated (yield given)	48MPa2
Elongation at break	30%11.67x more ductile	18%2
Young's modulus (stiffness)	3GPa11.82x stiffer	1.65GPa2
Density	1,130kg/m³1	930kg/m³222% lighter
Strength to weight	75.2kN·m/kg46% higher	51.6kN·m/kg
Stiffness to weight	2.65MN·m/kg50% higher	1.77MN·m/kg
Poisson's ratio	base material0.43	not sourced
Shear modulus	1.07GPa	not sourced
Bulk modulus	5GPa	not sourced
Speed of sound	1,629m/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 Nylon PA66	SLS PA12 Nylon
Thermal conductivity	0.33W/m·K1	not sourced
Thermal expansion	longitudinal98µm/m·K1	not sourced
100 mm part over a 50 °C swing	490µm growth	not sourced
Specific heat	1,700J/kg·K1	not sourced
Heats up and cools (diffusivity)	0.172mm²/s	not sourced
Thermal shock resistance	57.2W/m	not sourced
Melting point	DSC260°C184 °C higher	176°C2
Max service temperature	101°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

Try it on a partA bracket to run stress or thermal on, free in your browser	Open in LessCAD	Open in LessCAD

Sources3 documents: BASF, EOS GmbH, Covestro

Plastic Nylon PA66: BASF Ultramid A3K (PA66, unreinforced injection-moulding grade), Product Information 02/2026, dry values (ISO methods)
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
Ultramid A3K Product InformationBASFPlastic Nylon PA66 · Yield strength: typical, dryPlastic Nylon PA66 · Elongation at break: nominal strain at break, dryPlastic Nylon PA66 · Young's modulus (stiffness): typical, dryPlastic Nylon PA66 · Density: typicalPlastic Nylon PA66 · Thermal conductivity: typicalPlastic Nylon PA66 · Thermal expansion: longitudinal, 23-55 °CPlastic Nylon PA66 · Specific heat: typicalPlastic Nylon PA66 · Melting point: DSCPlastic Nylon PA66 · Max service temperature: IEC 60216 temperature index, 20000 h
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 Polymers Part and Mold Design: Thermoplastics, A Design GuideCovestroPlastic Nylon PA66 · Poisson's ratio: base material: unfilled polyamide (PA), conditioned, maker design-guide family value (Covestro Table 3-1)

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 Nylon PA66 stronger than SLS PA12 Nylon?

Plastic Nylon PA66 is stronger: its yield strength is 85 MPa against tensile strength 48 MPa for SLS PA12 Nylon (1.77x).

Which is lighter, Plastic Nylon PA66 or SLS PA12 Nylon?

SLS PA12 Nylon is lighter: 930 kg/m³ against 1,130 kg/m³ for Plastic Nylon PA66.

Which is stiffer, Plastic Nylon PA66 or SLS PA12 Nylon?

Plastic Nylon PA66 is stiffer: Young's modulus 3 GPa against 1.65 GPa for SLS PA12 Nylon, so the same part in Plastic Nylon PA66 deflects less under the same load.

Which is lighter for the same job, Plastic Nylon PA66 or SLS PA12 Nylon?

For the same stiffness or strength: Plastic Nylon PA66 is lighter for a stiff rod or tie (tension), stiff beam (bending), strong rod or tie, strong beam, strong panel or plate.

Part that must be	Plastic Nylon PA66	SLS PA12 Nylon
Stiff rod or tie (tension)	lighter	50% heavier
Stiff beam (bending)	lighter	11% heavier
Stiff panel or plate	about equal	about equal
Strong rod or tie	lighter	46% heavier
Strong beam	lighter	20% heavier
Strong panel or plate	lighter	10% 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 is more ductile, Plastic Nylon PA66 or SLS PA12 Nylon?

Plastic Nylon PA66 stretches further before it breaks: 30% elongation at break against 18% for SLS PA12 Nylon.