Features APPLICATION: The drawbar force gauge is compatible with all CAT 40 machines and Bt 40. This is a drawbar force gauge to make sure your Cat40 or Bt40 CNC mill has the correct holding force. FUNCTION: Spindles require routine maintenance. The use of this economical spindle drawbar force checking tool will maximize machine up time and minimize spindle down time costs associated with wear and damage of drawbars, clamping collets, pull studs, toolholders and tool tapers. By measuring the tool clamping force with this gage, spindle repair costs and repair time can be minimized. .