Steel Scratch Brush is a pen like steel scratch brush. Simply turn the knob at the top of the pen to allow more of the steel bristles to come out. Diameter of the steel portion of this brush is 4mm. This steel brush is used by both the watch and clockmaker for removing dirt and rust from both wheels, pinions and other assorted parts. Jewellers can use this brush for cleaning in between the links of bracelets as well as using this brush to create decorative finishes on metals.