The Shore Durometer A Scale is an industry-standard for measuring flexible rubber materials, and this is really important in choosing the right mold material for a particular job or in the case of choosing a casting material that might be a flexible casting material.

Durometer

To get started we need to first understand what is durometer or what the shore A durometer is. The A durometer is both the measurement and the gauge used to measure soft elastomer and what this is a gauge that has a little pin that sticks out at the bottom, and when that pin is pushed in flush with the base of the gauge that’s what gives you the reading on a given flexible material, so depending on how hard how far that pin pushed into the base is determines the hardness or softness of a material. The Shore D Scale measures the hardness of hard rubbers and hard plastics.

Below is a table of shore A hardness scales.

durometer scale

The A scale measures from a zero all the way up to a ninety-five, this is the most common scale for mold making materials. Most flexible rubber materials that you’ll be used for mold making or casting will be found somewhere on the Shore A scale. the low end of the scale a 0 or a 10 is going to be very soft, a high number will be very hard. In fact, the A scale a low number is going to feel very soft almost like human skin, a hard number would feel almost like hard plastic. Most of the materials we use for molding and casting are the lower end of the scale all the way up to the medium. A zero would be about like warm chewing gum, a 10 like human skin, a 50 to 60 would be about like a car tire and a roller skate wheel or a hard hat is going to measure around a 95. 

What materials and durometer can be compression and injection molded? How do you determine what durometer of material to use?

Please remember that the durometer selected will be based on the requirements of your project.

UKONG can help you to choose the material shore hardness for your next silicone project.