How to Measure the Hardness of Plastic Durometer Shore Hardness Scale (Shore D)

[@Kirillissimus]

The video is how NOT to measure hardness with the tools! The only good thing about it is that it shows almost all of the common mistakes. First of all, hardness testing using Shore's method defines "hardness" as depth of penetration of various shapes of tips under different forces, the standardized combinations are called "scales". D scale with the sharp tip you have calls for precisely 5kg of force and the spring in the device is designed to generate it when a flat surface of your material is in complete contact with the bottom surface of the device. If you do not provide the contact then you get hardness measurements significantly lower than the true values. It requires some effort to press hard enough for D scale but you can not get correct measurements without it, that is actually why they make specialized stands for the durometers so you could just turn a handle and let a weight on the top of the stand do all the work. Also you need to make sure that you have at least 12mm between the tip and all sides of the measured flat surface and at least 4mm of depth and if the measured part is a thin sheet then you need so rigidly support it from the bottom. Otherwise the part can significantly flex or some material will be pushed to one side and you will once again get incorect values. You definitely can not do it by just holding a part in your hand.

[@JAKOB1977]

I don't get it, how can you say "here you have it folks that's how you measure rigid plastic 2:20 for real?? LOL think about it, how should this durometer be able to measure this boat 1:20 when you only pushing it 50% down it not like this probe has some weird waves it is sending into the materiel. It needs a reference and that reference is when you pushing it ALL THE WAY DOWN, then the duometer will give a reading for how much penetration the spike had made into the material, aka hardness. but I'm pretty sure you need to push it all the way down before the durometer can reference itself to how far the pin is in the material. these test you're doing where 1 is only 1/3 down and the other is 50% down.. such a test will give you screwed readings.. you need to push the pin all the way down so it is bottoming out and then you can see the reading. check it yourself.. test with 1/3 down, and test with 50% down and test with 100% down, and you will see that you get way different readings and yep I also got one of these metal Durometer from China.. cost 12USD delivered.

[@uunknown3821]

Good point. I think what you're saying makes sense. Jacon Systems, would you please respond to Jacob's point. Anyway, thanks for the video.

[@GeekDetour]

I think he was afraid to destroy the objects. You are right: you need to push until the base is flush flat with the surface - the tip will certainly leave a mark.

[@RR-ok9po]

Thank you, good job explaining.