LATHE CNC BAR PULLER
CNA Lathe Bar Pullers, Lathe Bar Pull, Gripper
What does the bar puller do?
How it works...
Features and benefits

Dunham Tool manufactures high quality lathe bar pulls and bar puller kits to enhance bar stock puller applications. Dunham bar pullers are most frequently used as a CNC bar puller, but are also used in 'pick and place' applications. These tools are sometimes referred to as pull up bars.

The Dunham bar puller line of low cost bar pull grippers for CNC Lathes are available from 1/8" to 2" diameters in 1/16" increments, from 2" to 2 1/2" diameters in 1/8" increments, and from 3MM to 34MM in 1MM increments. Dunham bar pull grippers mount directly to the Dunham bar plull shank or use a Dunham bar pull adapter to mount to the shank; please see the Tables below for details.

The lightweight and self-activating Dunham bar puller has no moving parts, mounts in 60 seconds with gripper change in about 30 seconds, and does not interfere with other tools or cause turret imbalance. When a bar puller is used, the lathe turret no longer acts as a stock stop, reducing turret degradation and eliminating expensive, space-consuming, high maintenance bar feeds.

Employing a Dunham bar pull shank (available in 9 diameters as detailed in the Tables below) which is clamped in the lathe turret in the same manner as a boring bar, the grippers are hand turned onto the shank thread or onto adapters that attach to the shank to accept smaller diameter grippers. These self-activated grippers are slotted like standard collets and, as they advance over the bar to be pulled, are forced open to firmly grasp the bar for pulling out of the spindle to a programmed length. Only 1/4" bar engagement is needed. Gripping and release of the bar are automatic when the turret is advanced and retracted. CNC bar pull components are available individually or in kits. Bar pull shanks should be specified to the size of the boring tool holders.

  1. Mount shank in turret; screw on adapter (if required) and gripper.
  2. Insert bar through back of spindle and clamp with collet or chuck.
  3. Face off minimum 1/4" projection using parting off command in CNC program.
  4. Index turret to bar pull and traverse turret toward spindle for programmed distance, sliding gripper over stock.
  5. Release clamping pressure on bar.
  6. Retract turret programmed distance.
  7. Reclamp Bar.
  8. Retract turret sufficiently to clear gripper from bar.
  9. Begin programmed machining cycle.
  10. Repeat until all of bar is used.

  • Bar pull shanks fit in most boring tool holders
  • Low cost bar pull gripper replacements
  • Pull bar to last usable part length
  • Pull positions bar +/- 0.001"
  • Works close to chuck or collet nose
  • Does not interfere with adjacent tools or turret movement
  • Only 1/4" bar engagement require
* also referred to as " pull up bar "


 
Product Drawings For Bar Pull System

Choose either the GIF format to open in your browser or .dxf format which is in a self-extracting zip file. After downloading the file to a directory of your choice double click the .exe file and the .dxf files will be available for viewing in your CAD program. Refer to text file for the index of drawing listings.

  • Dunham Bar Pull Grippers: Size Chart: Inch gif format
  • Dunham Bar Pull Grippers: Size Chart: Metric gif format
  • Dunham Bar Pull Shanks: Size Chart: gif format
  • Dunham Bar Pull Adapters: Size Chart: gif format
 
Model Number and Description Dunham CNC Lathe Bar Puller

Bar Puller Kits Contain the Following Components:
Part NumberDescription
BAR-PULL-KIT-1
11 Grippers (1/4" to 1 1/2 in 1/8" increments) plus 5/8" and 1" adapters.
BAR-PULL-KIT-2 4 Grippers (1 5/8" to 2" in 1/8" increments) plus 1" adapter.
BAR-PULL-KIT-3 6 Grippers (3/16" to 1/2" in 1/16" increments) plus 5/8" adapter.
BAR-PULL-KIT-4 8 Grippers (9/16" to 1" in 1/16" increments) plus 5/8" and 1" adapter.
BAR-PULL-KIT-5 4 Grippers (1 1/8" to 1 1/2 in 1/8" increments) plus 1" adapter.
BAR-PULL-KIT-6 14 Grippers (3/16" to 1" in 1/16" increments) plus 8 grippers (1 1/8" to 2" in 1/8" increments) plus 5/8" and 1" adapter.
All kits above require choice of one Bar Pull Shank (see below)
BAR-PULL-KIT-7 Special Kit for Gang Tool CNC Lathes
10 Grippers (3/16" to 3/4" in 1/8" increments);
all grippers mount directly to Bar Pull Shank PB0625GT, no adapters required (this kit only);
Bar Pull Shank PB0625GT (5/8" GT) included (this kit only).


Bar Puller Grippers: INCH SIZES:
Part Number Description Part Description
PBG0187 Bar Puller Gripper 3/16" Require threaded adapter APB0625
PBG0250 Bar Puller Gripper 1/4" Require threaded adapter APB0625
PBG0312 Bar Puller Gripper 5/16" Require threaded adapter APB0625
PBG0375 Bar Puller Gripper 3/8" Require threaded adapter APB0625
PBG0437 Bar Puller Gripper 7/16" Require threaded adapter APB0625
PBG0500 Bar Puller Gripper 1/2" Require threaded adapter APB0625
PBG0562 Bar Pull Gripper 9/16" Require threaded adapter APB0625
PBG0625 Bar Puller Gripper 5/8" Require threaded adapter APB0625
PBG0687 Bar Puller Gripper 11/16" Require threaded adapter APB0625
PBG0750 Bar Puller Gripper 3/4" Require threaded adapter APB0625
PBG0812 Bar Puller Gripper 13/16" Require threaded adapter APB1000
PBG0875 Bar Puller Gripper 7/8" Require threaded adapter APB1000
PBG0937 Bar Puller Gripper 5/16" Require threaded adapter APB1000
PBG1000 Bar Puller Gripper 1" Require threaded adapter APB1000
PBG1062 Bar Puller Gripper 1 1/16" Require threaded adapter APB1000
PBG1125 Bar Puller Gripper 1 1/8" Require threaded adapter APB1000
PBG1187 Bar Puller Gripper 1 3/16" Require threaded adapter APB1000
PBG1250 Bar Puller Gripper 1 1/4" Require threaded adapter APB1000
PBG1312 Bar Puller Gripper 1 5/16" Mount directly to Bar Pull Shanks
PBG1375 Bar Puller Gripper 1 3/8" Mount directly to Bar Pull Shanks
PBG1437 Bar Puller Gripper 1 7/16" Mount Directly to Bar Pull Shanks
PBG1500 Bar Puller Gripper 1 1/2" Mount directly to Bar Pull Shanks
PBG1562 Bar Puller Gripper 1 9/16" Mount Directly to Bar Pull Shanks
PBG1625 Bar Puller Gripper 1 5/8" Mount directly to Bar Pull Shanks
PBG1687 Bar Puller Gripper 1 11/16" Mount Directly to Bar Pull Shanks
PBG1750 Bar Puller Gripper 1 3/4" Mount directly to Bar Pull Shanks
PBG1812 Bar Puller Gripper 1 13/16" Mount Directly to Bar Pull Shanks
PBG1875 Bar Puller Gripper 1 7/8" Mount directly to Bar Pull Shanks
PBG1937 Bar Puller Gripper 1 15/16" Mount Directly to Bar Pull Shanks
PBG2000 Bar Puller Gripper 2" Mount directly to Bar Pull Shanks
PBG2125 Bar Puller Gripper 2 1/8" Mount Directly to Bar Pull Shanks
PBG2250 Bar Puller Gripper 2 1/4" Mount Directly to Bar Pull Shanks
PBG2375 Bar Puller Gripper 2 3/8" Mount Directly to Bar Pull Shanks
PBG2500 Bar Puller Gripper 2 1/2" Mount Directly to Bar Pull Shanks
Bar Puller Shanks
Part Number Description
PB25MM Bar Pull Shank 25mm
PB0500 Bar Pull Shank 1/2"
PB0625 Bar Pull Shank 5/8"
PB0750 Bar Pull Shank 3/4"
PB0875 Bar Pull Shank 7/8"
PB1000 Bar Pull Shank 1"
PB1250 Bar Pull Shank 1 1/4"
PB1500 Bar Pull Shank 1 1/2"
PB0625GT For gang tool lathes only
Bar Puller Adapters
Part Number Description
APB0625 BarPull Adapter 5/8"
APB1000 BarPull Adapt 1"
APB1000GT BarPull Adapter 5/8" Gang Tool


Bar Puller Grippers: METRIC SIZES:
Part Number Description Part Description
PBG03MM Bar Puller Gripper 3mm Require threaded adapter APB0625
PBG004MM Bar Puller Gripper 4mm Require threaded adapter APB0625
PBG05MM Bar Puller Gripper 5mm Require threaded adapter APB0625
PBG06MM Bar Puller Gripper 6mm Require threaded adapter APB0625
PBG07MM Bar Puller Gripper 7mm Require threaded adapter APB0625
PBG08MM Bar Puller Gripper 8mm Require threaded adapter APB0625
PBG09MM Bar Pull Gripper 9mm Require threaded adapter APB0625
PBG10MM Bar Puller Gripper 10mm Require threaded adapter APB1000
PBG11MM Bar Puller Gripper 11mm Require threaded adapter APB1000
PBG12MM Bar Puller Gripper 12mm Require threaded adapter APB1000
PBG13MM Bar Puller Gripper 13mm Require threaded adapter APB1000
PBG14MM Bar Puller Gripper 14mm Require threaded adapter APB1000
PBG15MM Bar Puller Gripper 5mm Require threaded adapter APB1000
PBG16MM Bar Puller Gripper 16mm Require threaded adapter APB1000
PBG17MM Bar Puller Gripper 17mm Require threaded adapter APB1000
PBG18MM Bar Puller Gripper 18mm Require threaded adapter APB1000
PBG19MM Bar Puller Gripper 19mm Require threaded adapter APB1000
PBG20MM Bar Puller Gripper 20mm Require threaded adapter APB1000
PBG21MM Bar Puller Gripper 21mm Require threaded adapter APB1000
PBG22MM Bar Puller Gripper 22mm Require threaded adapter APB1000
PBG23MM Bar Puller Gripper 23mm Require threaded adapter APB1000
PBG24MM Bar Puller Gripper 24mm Require threaded adapter APB1000
PBG1562 Bar Puller Gripper 1 9/16" Require threaded adapter APB1000
PBG25MM Bar Puller Gripper 25mm Require threaded adapter APB1000
PBG26MM Bar Puller Gripper 26mm Require threaded adapter APB1000
PBG27MM Bar Puller Gripper 27mm Require threaded adapter APB1000
PBG28MM Bar Puller Gripper 28mm Require threaded adapter APB1000
PBG29MM Bar Puller Gripper 29mm Require threaded adapter APB1000
PBG30MM Bar Puller Gripper 30mm Require threaded adapter APB1000
PBG31MM Bar Puller Gripper 31mm Require threaded adapter APB1000
PBG32MM Bar Puller Gripper 32mm Require threaded adapter APB1000
PBG33MM Bar Puller Gripper 33mm Require threaded adapter APB1000
PBG34MM Bar Puller Gripper 34mm Require threaded adapter APB1000
 
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