SILICONE 40A 3D PRINTING
Formlabs Silicone 40A is a true 100% silicone — not a silicone-like acrylate. Printed on our Form 4, it produces soft, durable parts with 230% elongation, 12 kN/m tear strength and stable performance from -25°C to 125°C. It replaces mould-making for one-offs and small batches: gaskets, seals, grips, grommets and soft-touch parts, direct from your CAD file in days rather than weeks. A rare capability among UK print services — quotable instantly online.
WHEN SILICONE 40A IS THE RIGHT MATERIAL
- Seals, gaskets, grommets and dampeners — one-offs or small batches without tooling or casting.
- Soft-touch functional parts — grips, wearables, flexible fixtures and masking tools that survive repeated flexing (500,000+ flex cycles on the datasheet).
- Parts that need real silicone chemistry — chemical resistance and -25°C to 125°C thermal stability that rubber-like resins can't match.
- Soft moulds for casting urethane or resin — print the mould directly instead of casting it around a master.
WHEN SILICONE 40A IS THE WRONG MATERIAL
- Rigid or structural parts — at Shore 40A this is a soft elastomer. Use Tough 1500, Rigid 4000 or an FDM engineering material.
- Firmer rubber parts — if you need an 80A-durometer bumper or seal, Flexible 80A is closer and cheaper.
- High-volume production — above a few hundred units, conventional moulded silicone wins on unit cost. We're the right choice for prototypes, spares and short runs.
TECHNICAL DATA
| Property | Value | Notes |
|---|---|---|
| Shore hardness | 40A | Soft, pliable elastomer |
| Ultimate tensile strength | 5.5 MPa | Formlabs TDS, post-cured |
| Elongation at break | 230% | Stretches and recovers |
| Tear strength | 12 kN/m | Withstands repeated flex cycles |
| Rebound resilience | 34% | Formlabs TDS |
| Thermal stability | -25°C to 125°C | Silicone chemistry, not acrylate |
| Minimum feature size | 0.3mm | Fine features casting can't produce |
| Flex fatigue | >500,000 cycles | Ross flexing, notched, 23°C and -10°C |
| Build volume | 200×125×210mm | Formlabs Form 4 |
| Post-processing | Wash + post-cure included | Standard on every part |
PRICING
Quoted instantly online. Silicone 40A is a special-order resin — we order it in for your job and the quote tool shows the exact surcharge and any minimum before you pay anything.
GET YOUR SILICONE 40A QUOTE
Upload your STL, STEP, or mesh file to the quote tool. Price returns in seconds. Card, invoice (trade accounts) and bank-transfer payment accepted. Silicone 40A is a special-order resin — we bring it in for your job, so allow a little longer than a stocked material. The quote shows any surcharge and minimum before you pay.