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Clear vs Flexible Resin

Polymer · grade comparison

Clear and Flexible Resin are both polymer grades. Clear is the stronger of the two: tensile strength 65 MPa (9.43 ksi) against 9 MPa (1.29 ksi) for Flexible Resin, about 7.3 times as much. In exchange, Flexible Resin is the more ductile: elongation 120% versus 6.5% for Clear, and Clear is harder (80 Shore D vs 30 Shore D). Flexible Resin is lighter (1.12 g/cm³ vs 1.19 g/cm³ for Clear) and Clear is stiffer (2.8 GPa vs 0.01 GPa). On the shop floor, Clear machines more easily (fair vs poor) and Clear sits in a lower cost tier (standard, $$) than Flexible Resin (premium, $$$).

ClearChoose 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 weight is the constraint.

Clear vs Flexible Resin: properties

ClearFlexible Resin

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

2.8 GPa0.41 Msi
0.01 GPa0 Msi

Poisson's Ratio

0.38
0.48

Tensile Strength (Ultimate)

65 MPa9.4 ksi
9 MPa1.3 ksi

Yield Strength (0.2% offset)

52 MPa7.5 ksi
—

Elongation at Break

6.5%
120%

Compressive Strength

80 MPa11.6 ksi
5 MPa0.65 ksi

Compressive Modulus

2.6 GPa0.38 Msi
0.01 GPa0 Msi

Flexural Strength

87 MPa12.6 ksi
—

Flexural Modulus

2.2 GPa0.32 Msi
—

Shear Strength

40 MPa5.8 ksi
6 MPa0.87 ksi

Fracture Toughness (K_IC)

0.9 MPa·√m0.82 ksi·√in
—

Izod Impact, Notched

25 J/m0.47 ft·lbf/in
—

Hardness, Shore D

80 Shore D
30 Shore D

Hardness, Rockwell M

88 HRM
—

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

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

Glass Transition (Tg)

65°C149 °F
5°C41 °F

Water Absorption (24 h)

0.6%
1.2%

Water Absorption (Saturation)

1.6%
—

Refractive Index

1.52
1.5

Light Transmission

88%
—

Thermal

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

Specific Heat Capacity

1,450 J/kg·K0.35 BTU/lb·°F
1,650 J/kg·K0.39 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

110 µm/m·K61.1 µin/in·°F
180 µm/m·K100 µin/in·°F

Max Service Temperature (continuous)

55°C131 °F
65°C149 °F

Min Service Temperature

-30°C-22 °F
-20°C-4 °F

Heat Deflection Temp. @ 0.45 MPa

73°C163 °F
60°C140 °F

Heat Deflection Temp. @ 1.8 MPa

58°C136 °F
—

Vicat Softening Point (B50)

68°C154 °F
—

Same in both: Thermal Conductivity 0.2 W/m·K0.12 BTU/hr·ft·°F · Limiting Oxygen Index 19% · Max Service Temperature (short-term) 85°C185 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

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

Dielectric Strength

15 kV/mm381 V/mil
14 kV/mm356 V/mil

Dielectric Constant (1 MHz)

3.2
4

Dissipation Factor (1 MHz)

0.03
—

Volume Resistivity

1×10¹⁴ Ω·cm
1×10¹³ Ω·cm

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

65 / 100
70 / 100

Same in both: UV / Weathering Resistance 25 / 100

Manufacturability

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

Machinability

45 / 100
15 / 100

Weldability

5 / 100
—

Formability (cold)

5 / 100
—

Polishability

85 / 100
25 / 100

Mold Shrinkage

—
1.5%

Processing Melt Temperature (typ.)

—
30°C86 °F

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

110 MJ/kg47,292 BTU/lb
115 MJ/kg49,441 BTU/lb

Same in both: 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)

55 kN·m/kg
8 kN·m/kg

Specific Stiffness (E / density)

2.4 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 ResinFormlabs Clear

Manufacturing and finishing

CapabilityClearFlexible Resin
Default conditionStandardShore A 80
Relative cost$$ Standard$$$ Premium
Min. machined wall——
Best machined surface——

Both are offered for Injection molding and 3D printing. Both take the same 12 finishes: Chrome Plating (Plastic), Conductive Coating, Dyeing (Nylon), EMI Shielding Coating, Painting, Primer Coating, Soft Touch Coating, Spray Painting, Tinted Coating, UV Coating, Vacuum Metallization, Waterproof Coating.

Clear vs Flexible Resin — frequently asked

Is Clear stronger than Flexible Resin?

Yes. Clear has a typical tensile strength of 65 MPa (9.43 ksi) against 9 MPa (1.29 ksi) for Flexible Resin — about 7.3 times as much.

Which is cheaper, Clear or Flexible Resin?

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

Clear. Its machinability rates fair (45/100) against poor (15/100) for Flexible Resin.

Ready to make it?

Upload a CAD file and FabDigit prices the part in Clear 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.