FabDigitFabDigit

FFKM vs PP

Polymer · grade comparison

FFKM and PP are both polymer grades, both corrosion resistant plastic. PP is the stronger of the two: tensile strength 35 MPa (5.08 ksi) against 17 MPa (2.47 ksi) for FFKM, about 106% more. PP is lighter (0.91 g/cm³ vs 2 g/cm³ for FFKM) and PP is stiffer (1.5 GPa vs 0.01 GPa). On the shop floor, PP machines more easily (good vs poor) and PP sits in a lower cost tier (budget, $) than FFKM (standard, $$).

FFKMChoose it when the part sees heat.

PPChoose it when strength drives the design, or when weight is the constraint.

FFKM vs PP: properties

FFKMPP

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

0.01 GPa0 Msi
1.5 GPa0.22 Msi

Poisson's Ratio

0.49
0.42

Tensile Strength (Ultimate)

17 MPa2.5 ksi
35 MPa5.1 ksi

Elongation at Break

140%
150%

Shear Strength

12 MPa1.7 ksi
25 MPa3.6 ksi

Hardness, Shore A

75 Shore A
—

Tear Strength

18 kN/m103 lbf/in
—

Compression Set (22 h, 70 °C)

12%
—

Shear Modulus

—
0.55 GPa0.08 Msi

Bulk Modulus

—
3 GPa0.45 Msi

Yield Strength (0.2% offset)

—
33 MPa4.8 ksi

Compressive Strength

—
42 MPa6.1 ksi

Compressive Modulus

—
1.4 GPa0.2 Msi

Flexural Strength

—
45 MPa6.5 ksi

Flexural Modulus

—
1.5 GPa0.22 Msi

Fracture Toughness (K_IC)

—
3.5 MPa·√m3.2 ksi·√in

Izod Impact, Notched

—
30 J/m0.56 ft·lbf/in

Hardness, Shore D

—
72 Shore D

Hardness, Rockwell R

—
95 HRR

Physical

Density and transition temperatures.

Density

2 g/cm³0.07 lb/in³
0.91 g/cm³0.03 lb/in³

Glass Transition (Tg)

-3°C27 °F
-10°C14 °F

Water Absorption (24 h)

0.15%
0.02%

Melting Temperature (Tm)

—
165°C329 °F

Water Absorption (Saturation)

—
0.1%

Refractive Index

—
1.49

Thermal

How each material carries heat and how hot it can run.

Specific Heat Capacity

1,000 J/kg·K0.24 BTU/lb·°F
1,900 J/kg·K0.45 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

230 µm/m·K128 µin/in·°F
110 µm/m·K61.1 µin/in·°F

Max Service Temperature (continuous)

300°C572 °F
100°C212 °F

Min Service Temperature

-20°C-4 °F
-10°C14 °F

Limiting Oxygen Index

90%
18%

Max Service Temperature (short-term)

340°C644 °F
130°C266 °F

Heat Deflection Temp. @ 0.45 MPa

—
105°C221 °F

Heat Deflection Temp. @ 1.8 MPa

—
60°C140 °F

Vicat Softening Point (B50)

—
90°C194 °F

Same in both: Thermal Conductivity 0.22 W/m·K0.13 BTU/hr·ft·°F

Electrical

Conductivity and insulation.

Electrical Resistivity

1×10¹² Ω·m3.94×10¹⁹ µΩ·in
1×10¹⁴ Ω·m3.94×10²¹ µΩ·in

Dielectric Strength

18 kV/mm457 V/mil
25 kV/mm635 V/mil

Dielectric Constant (1 MHz)

4
2.25

Volume Resistivity

1×10¹⁴ Ω·cm
1×10¹⁶ Ω·cm

Dissipation Factor (1 MHz)

—
3×10⁻⁴

Surface Resistivity

—
1×10¹⁵ Ω

Comparative Tracking Index (CTI)

—
600 V

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

98 / 100
92 / 100

UV / Weathering Resistance

95 / 100
20 / 100

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

20 / 100
60 / 100

Mold Shrinkage

3.5%
1.6%

Mold Temperature (typ.)

190°C374 °F
40°C104 °F

Weldability

—
92 / 100

Formability (cold)

—
80 / 100

Polishability

—
40 / 100

Melt Flow Rate

—
12 g/10 min

Processing Melt Temperature (typ.)

—
230°C446 °F

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

400 MJ/kg171,969 BTU/lb
78 MJ/kg33,534 BTU/lb

Embodied Carbon (primary production)

28 kg CO₂/kg
2 kg CO₂/kg

Typical Recycled Content

0%
5%

Embodied Water

—
100 L/kg12 gal/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

9 kN·m/kg
39 kN·m/kg

Specific Stiffness (E / density)

0 MN·m/kg
1.7 MN·m/kg

Thermal Shock Resistance Index

1
0

Same in both: Thermal Diffusivity 0.1 mm²/s

Strength versus weight

Yield strength against density for every polymer grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.

0.1110100123Density (g/cm³)Yield strength (MPa) — log scalePPFFKM

Manufacturing and finishing

CapabilityFFKMPP
CNC machining—Yes
Sheet metal—Yes
3D printing—Yes
Default conditionSemiconductor GradeHomopolymer
Relative cost$$ Standard$ Budget
Min. machined wall—0.5 mm
Best machined surface—Ra 0.8 µm
Conductive Coating—Yes
Dyeing (Nylon)—Yes
Painting—Yes
Primer Coating—Yes
Tinted Coating—Yes
Vacuum Metallization—Yes
Waterproof Coating—Yes

Both are offered for Injection molding. They share 5 finishes: Chrome Plating (Plastic), EMI Shielding Coating, Soft Touch Coating, Spray Painting, UV Coating.

FFKM vs PP — frequently asked

Is PP stronger than FFKM?

Yes. PP has a typical tensile strength of 35 MPa (5.08 ksi) against 17 MPa (2.47 ksi) for FFKM — about 106% more.

Which is cheaper, FFKM or PP?

PP is the lower-cost material: it sits in the budget tier ($) while FFKM is standard ($$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.

Which is easier to machine, FFKM or PP?

PP. Its machinability rates good (60/100) against poor (20/100) for FFKM.

Ready to make it?

Upload a CAD file and FabDigit prices the part in FFKM and PP side by side — material, machining time, tolerance and finish in one quote. Certified material data ships with the order on request.

Typical handbook values for the conditions named above, normalised for comparison. Hardness on non-Brinell scales is converted approximately for charting only. Request certified data with your order for design-critical properties.