Making a Bend Die
Here is the process I used to make a bend die for 3″ OD tube on a 4″ center line radius. I used a 4140 series alloy steel blank.
-
- Cutting a disk off a 9″ dia x 13″ long chunk of alloy steel
-
- Centerdrilling the disk
-
- Drilling through hole with 1.5″ drill bit on my 1982 Bridgeport CNC mill
-
- Milling counterbore
-
- Facing end so it is perpendicular to through hole
-
- Clean-up pass on my little lathe
-
- Boring center for spindle clearance on the bender
-
- Discovered the cnc lathe I was going to use couldn’t swing 9″, so onto another lathe to reduce the diameter so it could fit
-
- One side roughed out on CNC lathe
-
- Both sides roughed out – still needed to take a final pass across all sufaces
-
- After final lathe pass and a little polishing
-
- Milling the notch for the clamp die. .020″ per pass – took a while
-
- Drilling the clamp die mounting holes
-
- The clamp die notch is complete
-
- Milling the keyway in bottom
-
- Counterboring the clamp die holes
-
- Forms for the wiper die pour
-
- Pour complete
-
- Tooling mounted on machine
-
- First bend. The wiper die needs a little work to clean up the slight wrinkles, but pretty good for first try
