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Castable Wax Resin vs Flexible Resin

Polymer · grade comparison

Castable Wax Resin and Flexible Resin are both polymer grades. Castable Wax Resin is the stronger of the two: tensile strength 12 MPa (1.74 ksi) against 9 MPa (1.29 ksi) for Flexible Resin, about 35% more. In exchange, Flexible Resin is the more ductile: elongation 120% versus 5% for Castable Wax Resin, and Castable Wax Resin is harder (78 Shore D vs 30 Shore D). Castable Wax Resin is stiffer (0.45 GPa vs 0.01 GPa) and Flexible Resin runs hotter in service (65°C vs 40°C continuous). On the shop floor, Castable Wax Resin machines more easily (25 vs 15 out of 100) and Flexible Resin sits in a lower cost tier (premium, $$$) than Castable Wax Resin (high, $$$$).

Castable Wax ResinChoose it when strength drives the design, or when the part is machined in volume.

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

Castable Wax Resin vs Flexible Resin: properties

Castable Wax ResinFlexible Resin

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

0.45 GPa0.07 Msi
0.01 GPa0 Msi

Tensile Strength (Ultimate)

12 MPa1.7 ksi
9 MPa1.3 ksi

Elongation at Break

5%
120%

Compressive Strength

30 MPa4.4 ksi
5 MPa0.65 ksi

Flexural Strength

18 MPa2.6 ksi
—

Flexural Modulus

0.5 GPa0.07 Msi
—

Izod Impact, Notched

12 J/m0.22 ft·lbf/in
—

Hardness, Shore D

78 Shore D
30 Shore D

Poisson's Ratio

—
0.48

Compressive Modulus

—
0.01 GPa0 Msi

Shear Strength

—
6 MPa0.87 ksi

Hardness, Shore A

—
80 Shore A

Tear Strength

—
24 kN/m137 lbf/in

Compression Set (22 h, 70 °C)

—
4%

Physical

Density and transition temperatures.

Density

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

Melting Temperature (Tm)

70°C158 °F
—

Glass Transition (Tg)

55°C131 °F
5°C41 °F

Water Absorption (24 h)

0.4%
1.2%

Refractive Index

—
1.5

Thermal

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

Specific Heat Capacity

1,900 J/kg·K0.45 BTU/lb·°F
1,650 J/kg·K0.39 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

150 µm/m·K83.3 µin/in·°F
180 µm/m·K100 µin/in·°F

Max Service Temperature (continuous)

40°C104 °F
65°C149 °F

Heat Deflection Temp. @ 0.45 MPa

48°C118 °F
60°C140 °F

Heat Deflection Temp. @ 1.8 MPa

38°C100 °F
—

Limiting Oxygen Index

—
19%

Max Service Temperature (short-term)

—
85°C185 °F

Same in both: Thermal Conductivity 0.2 W/m·K0.12 BTU/hr·ft·°F · Min Service Temperature -20°C-4 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

—
1×10¹¹ Ω·m3.94×10¹⁸ µΩ·in

Dielectric Strength

—
14 kV/mm356 V/mil

Dielectric Constant (1 MHz)

—
4

Volume Resistivity

—
1×10¹³ Ω·cm

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

UV / Weathering Resistance

20 / 100
25 / 100

Corrosion Resistance

—
70 / 100

Manufacturability

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

Machinability

25 / 100
15 / 100

Polishability

30 / 100
25 / 100

Mold Shrinkage

—
1.5%

Processing Melt Temperature (typ.)

—
30°C86 °F

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

—
115 MJ/kg49,441 BTU/lb

Embodied Carbon (primary production)

—
5.5 kg CO₂/kg

Typical Recycled Content

—
0%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

11 kN·m/kg
8 kN·m/kg

Specific Stiffness (E / density)

0.4 MN·m/kg
0 MN·m/kg

Thermal Shock Resistance Index

0
1

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

CapabilityCastable Wax ResinFlexible Resin
Injection molding—Yes
3D printing—Yes
Default condition—Shore A 80
Relative cost$$$$ High$$$ Premium
Min. machined wall——
Best machined surface——
Chrome Plating (Plastic)—Yes
Conductive Coating—Yes
Dyeing (Nylon)—Yes
EMI Shielding Coating—Yes
Painting—Yes
Primer Coating—Yes
Soft Touch Coating—Yes
Spray Painting—Yes
Tinted Coating—Yes
UV Coating—Yes
Vacuum Metallization—Yes
Waterproof Coating—Yes

Castable Wax Resin vs Flexible Resin — frequently asked

Is Castable Wax Resin stronger than Flexible Resin?

Yes. Castable Wax Resin has a typical tensile strength of 12 MPa (1.74 ksi) against 9 MPa (1.29 ksi) for Flexible Resin — about 35% more.

Which is cheaper, Castable Wax Resin or Flexible Resin?

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

Castable Wax Resin, by a small margin. Both rate poor for machinability — 25/100 against 15/100 for Flexible Resin.

Ready to make it?

Upload a CAD file and FabDigit prices the part in Castable Wax Resin and Flexible 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.