PCE-950 CE-2500 Metal Hardness Tester Portable handheld pen-sized durometer for use with steel, iron, aluminum, brass, bronze, copper and more. PCE-2500 is a portable, handheld, pen-sized, digital metal hardness tester, rebound hammer or durometer. This hardness tester quickly and accurately measures 10 common metal materials including steel / cast steel, alloy tool steel, stainless steel, lamellar iron, nodular iron, cast aluminum, brass, bronze, wrought copper and forging steel.