Keys to Using CNC Broach Tools

General Speeds/Feeds/Set-up

Speeds – 200 to 550 IPM (Inches per Minute)

Feeds – .0008″ – .0015″ DOC (Depth of Cut per pass)


  1. In 4140 – .0008″ DOC at 225 IPM
  2. In Aluminum – .0015″ DOC at 450-550 IPM
  3. In 8620 – .001″ DOC at 250 IPM


  • Program the tool to drop completely out of the keyway on the retraction, you do not want to drag the nose of the insert back through the slot on the retraction
  • Start cut with approx. 1” of space between the face of the insert and the part to allow space to accelerate to full cutting speed
  • imageFailure to have adequate “acceleration space” could result in deflection or tapering


How rigidly you hold our tool is the difference between whether it works well or not-

  • Use an ER collet or Cat40 style holder that holds the tool with multiple points of contact from different angles, we do NOT recommend you hold your ER collet shank in a VDI boring bar sleeve
  • End mill holders, boring bar sleeves or solid tool holders with only 2 screws from one direction are not adequate for best insert life
  • Take the time to indicate in your “Squareness to the Part at the Tip of the Cut” with gauge blocks
  • Our tools are long. If the tool is off in your holder by a .0001”, when you Trig out the length of the tool, 5” out at the tip of the cut you will be hitting the part “off”, dramatically decreasing your insert life


For the Operator

  • Do not over-tighten the set screws on our broach tools. Just snug them up.
  • Change the insert cutting edge out. A worn out insert will have a rounded, dull edge and won´t cut the part, but rather deflect. The force has to go somewhere.
  • Ensure the part you are cutting is clamped rigidly enough to withstand getting hit.
  • Use water soluble coolant with a 12-15% oil content from optimum insert life.