Plastic PBT GF30 vs. Plastic PTFE

Compare Plastic PBT GF30 vs. Plastic PTFE strength, stiffness, weight and thermal properties.

Plastic PBT GF30Bulk polymer (molded or machined)

Plastic PTFEBulk polymer (molded or machined)

Mechanical	Plastic PBT GF30	Plastic PTFE
Yield strength	not given (tensile used)	9MPa1
Ultimate tensile strength	stress at break140MPa2	39.3MPa3
Flexural strength	210MPa2	not sourced
Elongation at break	strain at break3%2	350%3117x more ductile
Young's modulus (stiffness)	9.8GPa2	not sourced
Density	1,530kg/m³241% lighter	2,160kg/m³3
Strength to weight	91.5kN·m/kg22x higher	4.17kN·m/kg
Stiffness to weight	6.41MN·m/kg	not sourced
Poisson's ratio	not sourced	0.461
Shear modulus	not sourced	not sourced
Bulk modulus	not sourced	not sourced
Speed of sound	2,531m/s	not sourced

Stiffness against densityHigher and further left: stiffer for its weight

Strength against densityHigher and further left: stronger for its weight

Thermal	Plastic PBT GF30	Plastic PTFE
Thermal conductivity	0.27W/m·K2	0.25W/m·K1
Thermal expansion	longitudinal25µm/m·K24x less	100µm/m·K1
100 mm part over a 50 °C swing	125µm growth4x less	500µm growth
Specific heat	1,050J/kg·K2	1,400J/kg·K133% higher
Heats up and cools (diffusivity)	0.168mm²/s2.03x faster	0.0827mm²/s
Thermal shock resistance	not sourced	not sourced
Melting point	DSC223°C2	second melting peak327°C3104 °C higher
Max service temperature	HDT 1.8 MPa205°C2	service temperature260°C4

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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Sources4 documents: Chemours, BASF

Plastic PBT GF30: BASF Ultradur B 4300 G6 (PBT, 30% glass fibre), injection moulding grade; product information sheet 09/2026, typical values for uncoloured product at 23 °C.
Plastic PTFE: Chemours Teflon PTFE 7C X granular molding resin, typical values (tensile/elongation measured on 0.13 mm skived tape)

1
Teflon PTFE Fluoropolymer Resin Properties HandbookChemoursarchived copyPlastic PTFE · Yield strength: typical yield strength at 23 °C (Teflon PTFE, Table 8)Plastic PTFE · Poisson's ratio: typical, 23 °C (Teflon PTFE resins, Chemours handbook)Plastic PTFE · Thermal conductivity: typical, granular resin, 4.6 mm specimenPlastic PTFE · Thermal expansion: typical, granular resin, 23-60 °C (ASTM E228)Plastic PTFE · Specific heat: typical, granular resin, 20 °C (ASTM D4591)
2
Ultradur B 4300 G6 Product InformationBASFPlastic PBT GF30 · Ultimate tensile strength: stress at break, 23 °CPlastic PBT GF30 · Flexural strength: typical, 23 °CPlastic PBT GF30 · Elongation at break: strain at break, 23 °CPlastic PBT GF30 · Young's modulus (stiffness): typical, 23 °CPlastic PBT GF30 · Density: typicalPlastic PBT GF30 · Thermal conductivity: typical (DIN 52612-1)Plastic PBT GF30 · Thermal expansion: longitudinal (flow), mean 23-55 °CPlastic PBT GF30 · Specific heat: typical, 23 °CPlastic PBT GF30 · Melting point: DSC (ISO 11357)Plastic PBT GF30 · Max service temperature: HDT 1.8 MPa
3
Teflon PTFE 7C X Product InformationChemoursarchived copyPlastic PTFE · Ultimate tensile strength: typical, skived tape 0.13 mmPlastic PTFE · Elongation at break: typical, skived tape 0.13 mmPlastic PTFE · Density: typical (standard specific gravity, ASTM D4894)Plastic PTFE · Melting point: second melting peak (sintered polymer), +/-10
4
Teflon PTFE 6C X Product InformationChemoursarchived copyPlastic PTFE · Max service temperature: service temperature (Chemours general Teflon PTFE statement)

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.

Questions

Mechanical

Is Plastic PBT GF30 stronger than Plastic PTFE?

Plastic PBT GF30 is stronger: its tensile strength is 140 MPa against yield strength 9 MPa for Plastic PTFE (15.6x).

Which is lighter, Plastic PBT GF30 or Plastic PTFE?

Plastic PBT GF30 is lighter: 1,530 kg/m³ against 2,160 kg/m³ for Plastic PTFE.

Which is lighter for the same job, Plastic PBT GF30 or Plastic PTFE?

For the same stiffness or strength: Plastic PBT GF30 is lighter for a strong rod or tie, strong beam, strong panel or plate.

Part that must be	Plastic PBT GF30	Plastic PTFE
Strong rod or tie	lighter	22x heavier
Strong beam	lighter	8.8x heavier
Strong panel or plate	lighter	5.57x 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 PBT GF30 or Plastic PTFE?

Plastic PTFE stretches further before it breaks: 350% elongation at break against 3% for Plastic PBT GF30.

Thermal

Which conducts heat better, Plastic PBT GF30 or Plastic PTFE?

Plastic PBT GF30 conducts heat better: 0.27 W/m·K against 0.25 W/m·K for Plastic PTFE.

Which expands less with temperature?

Plastic PBT GF30 expands less: 25 µm/m·K against 100 µm/m·K for Plastic PTFE.