SINGLE KNURL CUT TYPE HOLDERS
Straight knurling RAA
Right-hand knurl BR 30
Right-spiral RBR 30°
Straight knurl AA
Left-spiral RBL 30°
Straight knurl AA
Straight knurling RAA
Left-hand knurl BL 30°

  • This tool can produce a "straight" or a 30º "spiral" knurl.
    • Right-handed use: For a straight knurling on the component (RAA) you will need to fit one right-hand spiral knurl (BR30º). For a 30º right-spiral knurling on the component (RBR) you will need to fit one straight knurl (AA).
    • Left-handed use: For a straight knurling on the component (RAA) you will need to fit one left-hand spiral knurl (BL30º). For a 30º left-spiral knurling on the component (RBL) you will need to fit one straight knurl (AA).

      The knurl should be fitted to the holder as shown using a high temperature grease for initial lubrication. Tighten the socket cap screw to ensure the knurl is secured adequately and that it is free to rotate.

  • Now clamp the tool into the machine as shown above. Ensure that the top surface of the shank is exactly on centerline of the machine (this will be on the underside surface if mounted upside down on a CNC rear turret.)
  • Set the head in a level position and secure tightly by the main socket cap screw (A). Also tighten the two "jacking" screws (B) to prevent any rotation of the head.
  • Prepare your knurl blank diameter to suit the knurl being applied. Although this size can theoretically be calculated, trial and error is the preferred way to get best results. For reference purposes you can use the following formula: diameter = [ knurl pitch x #teeth being applied / pi x cos(helix) ]. Once a functional size has been established it should be held within ±0.03 mm (±.001").
  • These cut-knurling tools are designed to make a single pass across the material. The depth of this should be 0.5 x pitch of the knurl (i.e. if a 1.0 mm pitch knurl is being used, the cut depth after "touch on" will be 0.5 mm. radially (or 1.0 mm on dia.) Please refer to the recommended feeds and speeds for cut knurling.
  • Lubrication / coolant is very important, there should be a good "jet" blast of coolant at both wheels to ensure a quality knurl is achieved. This will prevent wheel seizure by keeping the solid bushes cool and at the same time, will wash the swarf away. Failure to wash away the swarf will result in small particles being rolled into the finished knurl profile thereby reducing the overall quality.
  • Method of approach is important. The knurl wheel should be plunged into the end of the workpiece VIA THE X-AXIS (not the z-axis) with an engagement length of 2 x pitch (but no more than 50% of the width of the wheel). It is important to penetrate the part at least 50% of the pitch of the knurl. Once at the correct depth the tool can traverse across the component in the usual way. At the end of traversing the tool should be retracted using the cross slide (X axis at the appropriate position).
  • If the resultant knurl has a spiral appearance of less than 5º it can be adjusted using the two jacking screws at the front of the head. If the error is more than 5º it indicates there is a center height problem with the set-up.
  • At regular intervals during the production run, make checks to ensure the knurl wheel is free to rotate and that it is not showing excessive signs of wear.

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