PFERD power wire tube brush for heavy-duty cleaning and deburring of I.D.'s: Threads, pipes, holes, keyways, etc. Heavy-duty construction offers long service life and most effective brushing action. Achieves optimal performance when fully chucked in drill presses and collet-equipped portable tools. Loop end of tube brush handle can be cut off for use in power tool. Recommended operating speed is between 500 and 2,500 RPM. To ensure a safe working environment, spin the brush up to operating speed while the tip of the brush is already inserted into the workpiece. When cleaning threads, run the brush in the same direction as the threads to prolong brush life. Specification: Diameter (inches): 3/8; Stem diameter (inches): 5/32; Brush part length (inches): 2; Overall length (inches): 6; Material: Brass Wire; Wire diameter (inches): .005.