Mold Silicone – Hard (40 Shore A) 5 kg

Unit Price for 1 EUR 180,05

Unit Price for 2 EUR 172,02 Unit Price for 3 EUR 163,99 Unit Price for 4 EUR 155,96 Unit Price for 5 EUR 147,93

Mold Silicone – Hard (40 Shore A) is a liquid silicone commonly used for creating casting molds. This silicone has a relatively firm hardness and is the hardest silicone in our range, making it ideal for casting applications that require high dimensional stability. It is easy to work with, releases cleanly from molds, and is non-toxic. The silicone is white but can be colored with our silicone pigments or alternatively with natural color pigments. PRO pigments are not compatible with silicone.

This is a tin-cure (condensation) silicone.

Mixing:

The silicone must be mixed with the included curing agent, which is packaged inside the container.
1 kg of silicone equals approx. 0.8 L.
For smaller batches, a syrings can be used to measure the curing agent precisely, though accuracy may be difficult. For a simpler 1:1 mixing ratio, we recommend our Heat Resistant Silicone.

If too much curing agent is added (more than 3%), the curing time will decrease. Conversely, using less than recommended will extend the curing time.

Handling:

Always wear gloves when working with silicone, as it can be sticky and difficult to remove from the skin.

Storage & Shelf Life:

Shelf life; 12 months
Optimal storage temperature: 5-10°C
Can be stored at higher temperatures, but storage above 25°C is not recommended.

Important:

This silicone is not EU food-grade approved, but our Heat Resistant Silicone holds FDA food safety certification in the U.S.

Learn more about our silicone and application below.

Description

Hard Silicone (40 Shore A) - Technical Data

Work time: max. 20 min
Cure time: approx. 5 hours
Hardness (shore A): 40
Color: White
Viscosity: ~21,000 mPa·s
Elasticity: 450%
Tensile strength: 4,8 MPa
Tear strength: 28 kN/m
Shrinkage: <0.2%
Melting point: 160ºC

Note: Data applies at 25°C room temperature.

Effecient Silicone Usage for Mold Production
Plan your silicone requirements accurately to optimize material use and reduce waste:

Choose a mold box with at least 1 cm clearance on all sides of your object.
Calculate the total box volume (Length x Width x Height).
Subtract the object’s volume using water displacement or CAD data
Convert volume to silicone weight: 1 kg silicone ≈ 800 cm³.

Example: A 15 × 9 × 10 cm mold box = 1350 cm³. Object volume = 230 cm³ → net silicone volume = 1120 cm³. Required silicone = 1120 ÷ 800 ≈ 1.4 kg.

Mixing and Working with Silicone

Each container of curing agent is designed for 1 kg of silicone.
Mix only the amount you need for the project.
Maximum working time after mixing: 20 minutes.

Forming and Layering

When creating multi-part molds, apply a thin layer of release agent on the cured silicone to prevent the new layer from bonding.
Same principle applies when casting silicone into a silicone mold: always use release agent to prevent adhesion between layers.

Tips

Use gloves when handling silicone.
Apply thin first layers to capture all details before adding thicker layers (5-10 mm) for mold strength.
Silicone cures at room temperature but can be accelerated with controlled heat.

Video Tutorial

Watch our step-by-step guide for casting silicone, demonstrating proper techniques including layering, release agent application, and mold finishing. Materials used in the tutorial include modeling clay, a cardboard box, petroleum jelly, and elastic bands.

Data Sheet: Mold silicone 30, 40, 50 - click here

Data sheet: Catalyst for Liquid silicone - click here