View Full Version : What is this mystery tool?

10-15-2011, 11:17 AM
This thing has a needle thing sticking out of the bottom. When the needle is pushed the hand on the dial goes up. There is a thing that looks like a knob on top but it does not turn. There is an 8-32 screw hole down the center of the knob thing. The top of the knob thing has a flat surface like it is suppose to bolt up flat against something. The side of the knob thing has a tiny window, maybe a screw pushes something down inside. There is also a U shape steel thing in the box. It says hardness type D. How does it work?





Grind Hard
10-15-2011, 11:21 AM
"Durometer is one of several measures of the hardness of a material. Hardness may be defined as a material's resistance to permanent indentation. The durometer scale was defined by Albert F. Shore, who developed a measurement device called a durometer in the 1920s. The term durometer is often used to refer to the measurement, as well as the instrument itself. Durometer is typically used as a measure of hardness in polymers, elastomers and rubbers."

This device is used to test the harness of rubber or plastic.

I have a friend locally who molds rubber and plastic he has several devices similar to this one... Digital and meter style.

10-15-2011, 02:26 PM
It's a durometer gauge, mine is an A scale for soft rubber and plastics, here are some pictures of mine. I used it for testing the hardness of printing press rollers, for best results attach a 1kg weight to the gauge and roll it on and then off of the pin, the weight is just to get consistent readings.

Yours may not be an A scale, I notice how pointy the needle is, it would surely damage soft rubber and the like. The calibration gauge should have a number stamped on the bottom of it, this is your reference for calibrating the gauge. There are different "shore" scales, for example, a reading of 20 on an A scale gauge would be much softer than the same reading (20) on a D scale gauge.

Oh, and the little screw down inside the threaded hole is the calibration screw, when you measure the little calibration block, this is the adjustment for making the redout dial match the stamped number on on the block.


10-15-2011, 02:59 PM
Oh, I see it now, your's is a D scale, which means that a 1kg weight won't be heavy enough to use the whole scale properly.