- Joined
- May 17, 2012
- Messages
- 104
DuMont has some good information on their web site: http://dumont.com/resource-center/broaching-hints/ . They have some suggestions for WreckWreck's problem:
Suggestions for a drifting or “hogging” Push-Type Keyway Broach:
The forces escalate quickly. My 1/8 broach need about 720 lb for maximum LOC in mild steel, but up the width by 1/32 of an inch to 5/32, and the force required nearly doubles, to 1320 lb. And a 3/16 is 1860 lbs. ! Closing in on a ton on a steel bar 3/16 wide. Keep things aligned! The size C broach for 3/16 only takes 1540 lbs, as it has 22 teeth vs. the 16 on the B broach.
My jet #3 is rated 3 tons, but only has a 16:1 ratio at the end of the arm, requiring 375 lb on the end of the bar to develop 3 tons... That ratio says my broach should take about 45 pounds to push through, and that seems about right (like picking up my granddaughter).
Suggestions for a drifting or “hogging” Push-Type Keyway Broach:
- Reverse workpiece or turn Broach so teeth face toward the back of the press.
- Let the Bushing protrude above the workpiece to give more support to the back of the Broach, thereby helping to keep it aligned. If a collared Bushing is used, place it upside down under the workpiece.
The forces escalate quickly. My 1/8 broach need about 720 lb for maximum LOC in mild steel, but up the width by 1/32 of an inch to 5/32, and the force required nearly doubles, to 1320 lb. And a 3/16 is 1860 lbs. ! Closing in on a ton on a steel bar 3/16 wide. Keep things aligned! The size C broach for 3/16 only takes 1540 lbs, as it has 22 teeth vs. the 16 on the B broach.
My jet #3 is rated 3 tons, but only has a 16:1 ratio at the end of the arm, requiring 375 lb on the end of the bar to develop 3 tons... That ratio says my broach should take about 45 pounds to push through, and that seems about right (like picking up my granddaughter).