Vacuum Casting Services for Prototypes and Small Batches
When you need 10–200 plastic parts that look and feel like injection moulded parts — but without the 8-week tooling wait — vacuum casting is the process engineers choose. At SkillsProto, we run silicone tooling and polyurethane (PU) resin casting to deliver production-feel prototypes and small-batch production parts in 5–10 working days.
Vacuum casting sits exactly between 3D printing (great for 1–10 units, layered surface) and injection moulding (great for 1,000+ units, longer tooling lead time). It is the workhorse process for design validation, market testing, user trials, trade show models and low-volume premium products.
When vacuum casting is the right process
- You need 10–200 plastic parts with injection-moulded appearance and feel.
- You want colour-matched, textured or transparent parts without committing to steel tooling.
- Your geometry has undercuts, fine details or thin walls that 3D printing would struggle with.
- You are testing multiple design variants quickly before locking the production CAD.
- You need soft-touch, rubber-like or overmoulded-feel parts for grip or seal validation.
Vacuum casting capabilities overview
| Capability | Specification |
|---|---|
| Master pattern | Stereolithography (SLA) or CNC machined master |
| Tooling | Silicone (RTV) mould, vacuum-degassed |
| Materials | PU resins: ABS-like, PC-like, PP-like, PMMA-like, PA-like, soft TPE (Shore 30A–95A) |
| Colours | Pre-coloured or batch-pigmented; clear / tinted translucent available |
| Fillers | Glass fibre, mineral-filled grades available on request |
| Max part size | 500 × 500 × 250 mm typical |
| Standard tolerance | ±0.2 mm on cast features |
| Wall thickness | 0.8 mm – 6 mm |
| Typical lead time | 5–10 working days after master approval |
| Batch size | 10–200 parts per silicone tool |
Materials and finishes for vacuum cast parts
We carry a wide library of PU resins to match the mechanical and tactile properties your design requires:
- ABS-like — general-purpose engineering thermoplastic feel; opaque, good impact.
- PP-like — flexible, chemical-resistant, living hinge feel.
- PC-like — rigid, transparent, high-impact feel.
- PMMA-like (acrylic) — glass-clear, polish-able, premium feel.
- PA-like (nylon) — wear resistant, slight moisture absorption.
- Soft TPE / rubber-like — Shore 30A to 95A, soft-touch grips and seals.
- Filled grades — glass-filled (stiffer) and fire-retardant options on request.
Surface finishes are applied after casting:
- As-cast (glossy silicone surface, slight parting line).
- Bead blasting (matte, hides minor blemishes).
- Painting (custom colour matched to RAL / Pantone, primer + base + clear coat).
- Pad printing, silk-screen and laser marking (logos, part numbers, scales).
- Chrome plating, soft-touch rubber coating (premium consumer-product finish).
Vacuum casting vs injection moulding vs 3D printing
| Factor | Vacuum Casting | Injection Moulding | 3D Printing |
|---|---|---|---|
| Best for | 10–200 parts, production-like plastic feel | 1,000+ parts, repeatable, tight tolerance | 1–10 parts, complex geometry |
| Tooling cost | Low (silicone, days) | High (steel, weeks) | None |
| Lead time | 5–10 days | 15–30 days (prototype aluminium) / 8–12 weeks (steel) | 2–5 days |
| Tolerance | ±0.2 mm | ±0.05 mm | ±0.2 mm |
| Surface finish | Smooth, paintable | Smooth, paintable | Layered (needs finishing for cosmetic) |
| Cost per part | Medium-low | Low at volume | High per part |
| Material feel | Production-like | Production | Plastic-y / limited |
Industries served with vacuum casting
- Consumer products — premium enclosures, ergonomic handles, soft-touch grips.
- Automotive interior — dashboard mock-ups, switchgear, light covers, trim.
- Medical — device housings, ergonomic models for clinical trials, training models.
- Electronics — wearable enclosures, headphone shells, remote control bodies.
- Design agencies — pitch models, exhibition pieces, design validation samples.
Our vacuum casting process
- CAD check — wall thickness, draft, undercuts, parting strategy reviewed with you.
- Master production — SLA or CNC master made from your CAD.
- Silicone tooling — RTV silicone cast around master, vacuum-degassed, cured.
- Sample casting — first shots inspected for cosmetics, wall thickness, colour.
- Production casting — full batch cast under vacuum, degassed, finished.
- QA and shipping — dimensional check, cosmetic inspection, packed and shipped.
Frequently Asked Questions (Vacuum Casting)
Q1: What is the maximum batch size you can cast from one silicone tool? A: Typically 15–30 shots per silicone tool before tooling wear affects cosmetics. For 50–200 unit runs we plan multiple silicone tools cast from the same master, so all parts are dimensionally consistent.
Q2: Can you colour-match a Pantone or sample chip? A: Yes. Send a Pantone code, RAL reference or a physical sample and we will formulate a batch-pigmented resin. We include colour-matching samples for approval before full production.
Q3: Are vacuum cast parts suitable for functional testing? A: Yes for mechanical fit, snap-fit, assembly trials and ergonomic testing. For high-stress structural testing, SLS or MJF nylon is a better choice. We will advise the right process for your test case.
Q4: Can you under-mould or over-mould metal inserts? A: Yes. We routinely cast around threaded inserts, studs and metal cores. Send your assembly CAD and we will design the casting around the inserts.
Q5: How long does a silicone tool last? A: With care, a single silicone tool yields 15–30 production-grade parts. After that, mould surface starts to dull and parts lose cosmetics. We replace the mould rather than refurbish it.
Request a vacuum casting quote
Send your CAD, target quantity, material preference and any colour reference for a quote within 24 hours.
[Request a Quote — Vacuum Casting]