Optical Brinell Hardness Testing Machine Model OPFB-3000 Features We have developed Brinell Hardness Testing Machine with an optical device. Basic machine design and operation are similar to TKB- 3000, with a built-in optical device with 14 X magnification provided in front to project the diameter of the ball impression on a glass screen with a micrometer measuring system with 0.01 mm least count. In this machine the indentor swivels and projects the diameter of the ball impression immediately after the unloading operation which avoids additional time for measurement of the ball impression. This is a production testing machine. This is suitable for foundries, forging shops, heat treatment shops, engineering institutions, etc.