Plastic Nylon PA66 vs. Solder SAC305

Compare Plastic Nylon PA66 vs. Solder SAC305 strength, stiffness, weight and thermal properties.

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Plastic Nylon PA66Bulk polymer (molded or machined)

Mechanical
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Yield strength	85MPasourcetypical, dry	22MPasourcetypical
Ultimate tensile strength	not sourced	39.6MPasourcetypical
Elongation at break	30%sourcenominal strain at break, dry	49%sourcetypical
Young's modulus (stiffness)	3GPasourcetypical, dry	6.9GPasourcetypical, temperature and strain rate not stated
Density	1,130kg/m³sourcetypical6.5x lighter	7,350kg/m³sourcetypical
Strength to weight	75.2kN·m/kg25.1x higher	2.99kN·m/kg
Stiffness to weight	2.65MN·m/kg2.83x higher	0.939MN·m/kg
Poisson's ratio	0.4sourcebase material: unfilled polyamide (PA), conditioned, maker design-guide family value (Covestro Table 3-1)	0.35sourcetypical
Shear modulus	1.07GPa	2.56GPa2.39x stiffer in shear
Bulk modulus	5GPa	7.67GPa
Speed of sound	1,629m/s	969m/s
Thermal
Thermal conductivity	0.33W/m·Ksourcetypical	61W/m·Ksourcetypical, temperature not stated
Thermal expansion	98µm/m·Ksourcelongitudinal, 23-55 °C	21.9µm/m·Ksourcemean, 20-100 °C (MacDermid Alpha)
100 mm part over a 50 °C swing	490µm growth	110µm growth4.47x less
Specific heat	1,700J/kg·Ksourcetypical	232J/kg·Ksourcetypical (MacDermid Alpha)
Heats up and cools (diffusivity)	0.172mm²/s	35.8mm²/s208x faster
Thermal shock resistance	57.2W/m	5,773W/m101x more resistant
Melting point	260°CsourceDSC	217–220°Csourcesolidus-liquidus
Max service temperature	101°CsourceIEC 60216 temperature index, 20000 h	not sourced
Values for	BASF Ultramid A3K (PA66, unreinforced injection-moulding grade), Product Information 02/2026, dry values (ISO methods)	SAC305 (Sn96.5Ag3.0Cu0.5) solder alloy, bulk; Indium Corporation Indalloy 256 (SAC305) for Preforms product data sheet (Form No. 100346 R0, 2024), selected properties, test temperature not stated; expansion and specific heat from MacDermid Alpha VACULOY SAC TDS (06 September 2023).

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.

Questions

Is Plastic Nylon PA66 stronger than Solder SAC305?

Plastic Nylon PA66 is stronger: its yield strength is 85 MPa against 22 MPa for Solder SAC305 (3.86x).

Which is lighter, Plastic Nylon PA66 or Solder SAC305?

Plastic Nylon PA66 is lighter: 1,130 kg/m³ against 7,350 kg/m³ for Solder SAC305.

Which is stiffer, Plastic Nylon PA66 or Solder SAC305?

Solder SAC305 is stiffer: Young's modulus 6.9 GPa against 3 GPa for Plastic Nylon PA66, so the same part in Solder SAC305 deflects less under the same load.

Which is lighter for the same job, Plastic Nylon PA66 or Solder SAC305?

For the same stiffness or strength: Plastic Nylon PA66 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 Nylon PA66	Solder SAC305
Stiff rod or tie (tension)	lighter	2.83x heavier
Stiff beam (bending)	lighter	4.29x heavier
Stiff panel or plate	lighter	4.93x heavier
Strong rod or tie	lighter	25.1x heavier
Strong beam	lighter	16x heavier
Strong panel or plate	lighter	12.8x 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 PA66 or Solder SAC305?

Solder SAC305 conducts heat better: 61 W/m·K against 0.33 W/m·K for Plastic Nylon PA66.

Which expands less with temperature?

Solder SAC305 expands less: 21.9 µm/m·K against 98 µm/m·K for Plastic Nylon PA66.

Among 72 materials

Stiffness against density

Strength against density