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Manufacturing services · Chapter A · Method 02

Cast silicone tooling

Core TCI route

Two-part or multi-part silicone tools with registration keys and a planned parting line, made to cast resin, wax, soap, concrete or food repeatedly.

Weighing a two-part silicone before mixing.
Weighing a two-part silicone before mixing. TCI workshop
Finished cast silicone parts with relief detail.
Finished cast silicone parts with relief detail. TCI workshop

How it works

Cast silicone tooling, step by step.

A labelled schematic of the process (not to scale), and the four steps every job goes through.

Labelled diagram showing how cast silicone tooling works
Schematic · not to scale. Drawn by TCI Group.
STEP 01

Parting plan

Decide split lines, keys, sprues and vents on the master.

STEP 02

First half

Bed the master in clay or a printed former; pour half one.

STEP 03

Second half

Release, then pour the second half against the first.

STEP 04

Open & prove

Open, remove master, trial-cast and adjust vents.

Reference figures

What to expect.

Typical industry values to help you plan. We agree the figures for your part on the drawing.

HardnessShore A 10–60Choose for flex vs. stability
Parts~20–25 per mouldTypical for PU casting
ShrinkLow (platinum)Check each datasheet
ToleranceAgreed per projectSet at sample approval
MaterialsPlatinum and tin-cure silicones; casting media include polyurethane, epoxy, wax, soap, gypsum, concrete and food.
FinishesAs master; matte or gloss. Release agents and barrier coats where the casting chemistry needs them.
Design guidance
  • Put the parting line on edges where a witness line is acceptable.
  • Use keys and a rigid case for parts that must stay true.
  • Plan draft where possible; silicone tolerates undercuts but long runs prefer draft.
Best suited toShort-run parts, decorative products, construction and restoration castings, and production moulds for customers.
Watch-outsAggressive resins and heat shorten mould life. Long, thin parts may need a support jacket to avoid distortion.

More in chapter A

Other methods in Silicone & rubber

Next step

Not sure this is the right route?

Send a sketch, photo, sample or CAD file with your quantity and target date. We will recommend the most sensible route and explain the trade-offs before quoting.

Reference figures are typical published industry values for planning, not a guarantee; final tolerances, materials and finishes are agreed in writing for each project.