... EXPERIENCE, PROFESSIONAL MANUFACTURERING TECHNOLOGY , AND A STRICT QUALITY CONTROL SYSTEM. 1",2", 3", 4", 5", 6" RUBBER WHEEL Verified Information ... 0 Acceptable Thread Tester No Information 1 3.0 Acceptable Rubber Hardness Tester LX-A 1 3.0 Acceptable Universal Testing Machine ... WDW-20A 1 3.0 Acceptable Brinell Hardness ...