Elastic Resin A40
Hardness band
A40 = shore A 40
Intermediate softness for seals and wearables that need more support than A30 but stay pliable.
Values for the A40 condition
Other Elastic Resin grades and fills
Elastic Resin is listed in 6 conditions; see the grade overview at Elastic Resin.
Compare all 6 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
Shore A 30 | Pick for the softest silicone feel — squeeze bulbs, soft pads and skin-like models where strength is secondary. | — | 2 | 220 | 6 Shore D |
A40This page Shore A 40 | Intermediate softness for seals and wearables that need more support than A30 but stay pliable. | — | 2 | 190 | 9 Shore D |
A50Default Shore A 50 | Default silicone-like grade: best balance of softness, elongation and tear for gaskets, grips and anatomical models. | — | 3 | 160 | 13 Shore D |
True silicone (100% silicone) printable elastomer, Shore A 40 | Choose when real silicone chemistry is required — high-temperature service, low compression set, long-term elasticity rather than a silicone-like acrylate. | — | 4 | 260 | 40 Shore A |
High-tear industrial elastomeric resin | Choose for functional seals, jigs and low-volume end-use rubber parts that must survive repeated flexing and demoulding. | — | 7 | 200 | 18 Shore D |
Shore A 80 | Use when the part must be rubbery but load-bearing — hinges, bumpers, over-molded grips, TPU-like prototypes. | — | 9 | 120 | 30 Shore D |
What is Elastic Resin A40?
Elastic Resin A40 is Elastic Resin heat treated to A40 — intermediate softness for seals and wearables that need more support than A30 but stay pliable. Elastic Resin A40 has a tensile strength of 2 MPa (0.348 ksi), weaker than 84% of polymer grades. Elongation at break is 190% and the elastic modulus is 0 GPa (2.76×10⁻⁴ Msi). Elastic Resin A40 has a density of 1.12 g/cm³ (0.0405 lb/in³), lighter than 64% of polymer grades. Its glass-transition temperature is 5°C (41 °F). A50 is the default condition FabDigit quotes; A40 is available on request or by drawing note.
Advantages
- Ductile — tolerates forming and impact — 190%, better than 75% of polymer grades
Limitations
- Difficult to machine — 10/100, worse than 100% of polymer grades
- Low stiffness — 0 GPa (2.76×10⁻⁴ Msi), worse than 95% of polymer grades
- Hard to polish — 20/100, worse than 95% of polymer grades
- Limited service temperature — 58°C (136 °F), worse than 89% of polymer grades
- High mold shrinkage — 2.2%, worse than 87% of polymer grades
Elastic Resin A40 properties
Typical room-temperature values for Elastic Resin A40; 14 are specific to this condition. Other listed values are Elastic Resin reference data and may not represent this condition. Bars are the position among polymer grades.
Physical6
Elastic Resin A40 has a density of 1.12 g/cm³ (0.0405 lb/in³), lighter than 64% of polymer grades. Its glass-transition temperature is 5°C (41 °F).
Mechanical12
Elastic Resin A40 has a tensile strength of 2 MPa (0.348 ksi), weaker than 84% of polymer grades. Elongation at break is 190% and the elastic modulus is 0 GPa (2.76×10⁻⁴ Msi).
Thermal8
Elastic Resin A40 is rated for continuous service to 58°C (136 °F). It conducts heat at 0.18 W/m·K (0.104 BTU/hr·ft·°F), worse than 73% of polymer grades. Thermal expansion is 190 µm/m·K (105.6 µin/in·°F).
Electrical5
Elastic Resin A40 is an electrical insulator with a dielectric strength of 14 kV/mm (355.6 V/mil) and a resistivity of 1×10¹¹ Ω·m.
Chemical & Environmental3
Corrosion resistance is very good (70/100), worse than 78% of polymer grades. UV resistance is poor.
Sustainability4
Producing a kilogram of Elastic Resin A40 takes about 120 MJ of energy and emits 6 kg of CO₂ — more than 73% of polymer grades. Typical recycled content is 0%.
Manufacturability3
Elastic Resin A40's machinability is not recommended (10/100, worse than 100% of polymer grades).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Elastic Resin A40
Is Elastic Resin easy to machine?
Effectively unmachinable — cut only with sharp blades, cryo-trim or waterjet; drilling and milling smear and tear the soft matrix.
Can Elastic Resin be welded?
Not weldable; join with cyanoacrylate, silicone/urethane adhesives or by co-printing/over-moulding onto rigid parts.
Can Elastic Resin be formed, bent or molded?
Print with dense internal supports and thick walls (>1.5 mm), keep the resin tank warm (~30 °C) and expect noticeable cure and post-cure shrinkage; also usable as a castable soft pattern.
What surface finishes work on Elastic Resin?
Wash briefly in IPA (long soaks swell and weaken parts), fully post-cure with heat to remove tack, then dust with talc or apply a silicone-compatible coating; cannot be sanded to a gloss.
Elastic Resin chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| aliphatic urethane acrylate / methacrylasoft-segment backbone that sets elasticity | 40 – 70 | 55 |
| monofunctional acrylate reactive diluentviscosity control, chain extender | 20 – 50 | 35 |
| low-functionality crosslinker (di-acrylakept low to preserve elongation | 1 – 8 | 4 |
| photoinitiator (TPO / TPO-L / BAPO)385/405 nm absorption | 0.5 – 3 | 1.5 |
| UV blocker, stabilizer, pigmentcure-depth control and colour | 0.05 – 2 | 0.5 |
Elastic Resin A40 — frequently asked
What is Elastic Resin A40 used for?
Elastic Resin A40 is typically used for cushions, seals, prosthetic mockups and soft grips. In short: softest SLA elastomer range; 160% elongation; silicone-like feel.
What is the tensile strength of Elastic Resin A40?
Elastic Resin A40 has a typical tensile strength of 2 MPa (0.348 ksi) — weaker than 84% of polymer grades. Strength varies by condition: see the 6 listed tempers.
Is Elastic Resin A40 easy to machine?
Not especially — machinability is rated not recommended (10/100, worse than 100% of polymer grades). Effectively unmachinable — cut only with sharp blades, cryo-trim or waterjet; drilling and milling smear and tear the soft matrix.
Can Elastic Resin A40 be welded?
Not weldable; join with cyanoacrylate, silicone/urethane adhesives or by co-printing/over-moulding onto rigid parts.
What surface finishes work on Elastic Resin A40?
Wash briefly in IPA (long soaks swell and weaken parts), fully post-cure with heat to remove tack, then dust with talc or apply a silicone-compatible coating; cannot be sanded to a gloss.
Can Elastic Resin A40 be formed, bent or molded?
Print with dense internal supports and thick walls (>1.5 mm), keep the resin tank warm (~30 °C) and expect noticeable cure and post-cure shrinkage; also usable as a castable soft pattern.
What is the maximum service temperature of Elastic Resin A40?
Elastic Resin A40 is rated for continuous use to about 58°C (136 °F), and briefly to 90°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- Elastic 50A / Flexible 80A / BioMed Elastic 50A / Silicone 40A resin data sheets — Formlabs (2024)
- Elastomeric and flexible photopolymer technical data sheets — Liqcreate / Siraya Tech / Henkel Loctite 3D (2024)
- ASTM D412 / D624 / D2240 / D395 — tensile, tear, durometer and compression set of elastomers — ASTM International (2021)
- Handbook of Polyurethanes / UV-curable acrylate elastomer property data — CRC Press (2011)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.