FabDigitFabDigit

Flexible Resin vs Water-Washable Resin

Polymer · grade comparison

Flexible Resin and Water-Washable Resin are both polymer grades. Water-Washable Resin is the stronger of the two: tensile strength 42 MPa (6.09 ksi) against 9 MPa (1.29 ksi) for Flexible Resin, about 4.7 times as much. In exchange, Flexible Resin is the more ductile: elongation 120% versus 8% for Water-Washable Resin, and Water-Washable Resin is harder (80 Shore D vs 30 Shore D). Water-Washable Resin is stiffer (2.2 GPa vs 0.01 GPa) and Flexible Resin runs hotter in service (65°C vs 50°C continuous). On the shop floor, Water-Washable Resin machines more easily (fair vs poor) and Flexible Resin sits in a lower cost tier (premium, $$$) than Water-Washable Resin (high, $$$$).

Flexible ResinChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

Water-Washable ResinChoose it when strength drives the design, or when the part is machined in volume.

Flexible Resin vs Water-Washable Resin: properties

Flexible ResinWater-Washable Resin

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

0.01 GPa0 Msi
2.2 GPa0.32 Msi

Poisson's Ratio

0.48
0.38

Tensile Strength (Ultimate)

9 MPa1.3 ksi
42 MPa6.1 ksi

Elongation at Break

120%
8%

Compressive Strength

5 MPa0.65 ksi
75 MPa10.9 ksi

Compressive Modulus

0.01 GPa0 Msi
—

Shear Strength

6 MPa0.87 ksi
—

Hardness, Shore A

80 Shore A
—

Hardness, Shore D

30 Shore D
80 Shore D

Tear Strength

24 kN/m137 lbf/in
—

Compression Set (22 h, 70 °C)

4%
—

Flexural Strength

—
65 MPa9.4 ksi

Flexural Modulus

—
2.1 GPa0.3 Msi

Izod Impact, Notched

—
20 J/m0.37 ft·lbf/in

Physical

Density and transition temperatures.

Density

1.12 g/cm³0.04 lb/in³
1.13 g/cm³0.04 lb/in³

Glass Transition (Tg)

5°C41 °F
60°C140 °F

Water Absorption (24 h)

1.2%
2.2%

Refractive Index

1.5
1.51

Water Absorption (Saturation)

—
5%

Thermal

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

Thermal Conductivity

0.2 W/m·K0.12 BTU/hr·ft·°F
0.19 W/m·K0.11 BTU/hr·ft·°F

Specific Heat Capacity

1,650 J/kg·K0.39 BTU/lb·°F
1,500 J/kg·K0.36 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

180 µm/m·K100 µin/in·°F
100 µm/m·K55.6 µin/in·°F

Max Service Temperature (continuous)

65°C149 °F
50°C122 °F

Heat Deflection Temp. @ 0.45 MPa

60°C140 °F
55°C131 °F

Max Service Temperature (short-term)

85°C185 °F
70°C158 °F

Heat Deflection Temp. @ 1.8 MPa

—
45°C113 °F

Same in both: Min Service Temperature -20°C-4 °F · Limiting Oxygen Index 19%

Electrical

Conductivity and insulation.

Electrical Resistivity

1×10¹¹ Ω·m3.94×10¹⁸ µΩ·in
1×10¹² Ω·m3.94×10¹⁹ µΩ·in

Dielectric Strength

14 kV/mm356 V/mil
17 kV/mm432 V/mil

Dielectric Constant (1 MHz)

4
3.8

Volume Resistivity

1×10¹³ Ω·cm
1×10¹⁴ Ω·cm

Dissipation Factor (1 MHz)

—
0.04

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

70 / 100
55 / 100

Same in both: UV / Weathering Resistance 25 / 100

Manufacturability

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

Machinability

15 / 100
50 / 100

Polishability

25 / 100
60 / 100

Mold Shrinkage

1.5%
0.4%

Processing Melt Temperature (typ.)

30°C86 °F
—

Sustainability

Primary-production footprint per kilogram.

Embodied Carbon (primary production)

5.5 kg CO₂/kg
5.2 kg CO₂/kg

Embodied Water

—
220 L/kg26.4 gal/lb

Same in both: Embodied Energy (primary production) 115 MJ/kg49,441 BTU/lb · Typical Recycled Content 0%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

8 kN·m/kg
37 kN·m/kg

Specific Stiffness (E / density)

0 MN·m/kg
1.9 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 scaleFlexible Resin

Manufacturing and finishing

CapabilityFlexible ResinWater-Washable Resin
Injection moldingYes—
3D printingYes—
Default conditionShore A 80—
Relative cost$$$ Premium$$$$ High
Min. machined wall——
Best machined surface——
Chrome Plating (Plastic)Yes—
Conductive CoatingYes—
Dyeing (Nylon)Yes—
EMI Shielding CoatingYes—
PaintingYes—
Primer CoatingYes—
Soft Touch CoatingYes—
Spray PaintingYes—
Tinted CoatingYes—
UV CoatingYes—
Vacuum MetallizationYes—
Waterproof CoatingYes—

Flexible Resin vs Water-Washable Resin — frequently asked

Is Water-Washable Resin stronger than Flexible Resin?

Yes. Water-Washable Resin has a typical tensile strength of 42 MPa (6.09 ksi) against 9 MPa (1.29 ksi) for Flexible Resin — about 4.7 times as much.

Which is cheaper, Flexible Resin or Water-Washable Resin?

Flexible Resin is the lower-cost material: it sits in the premium tier ($$$) while Water-Washable Resin is high ($$$$). 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, Flexible Resin or Water-Washable Resin?

Water-Washable Resin. Its machinability rates fair (50/100) against poor (15/100) for Flexible Resin.

Ready to make it?

Upload a CAD file and FabDigit prices the part in Flexible Resin and Water-Washable Resin 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.