Stuck On Broach
||1. Insufficient machine capacity.
||1. Check broaching machine to see if it is delivering rated
||2. Dull cutting edges.
||2. Check broach design, perhaps back-off clearance is insufficient
or step per tooth is too great.
|3. Clogged tooth gullets.
||3. Sharpen broach if required. Check tooth design.
|4. Failure of power during cutting stroke.
||4. Each tooth gullet should be cleared of chips between passes.
|5. Misalignment of the broach puller with workpiece.
||5. Check alignment of fixture for holding workpiece with centerline
of broach puller.
|6. Hole in workpiece not square with face which contacts fixture.
||6. Be sure that the hole in the workpiece is square with the
face that contacts the fixture.
|Galling Or Pickup
||1. Too low or variations in hardness of workpiece.
||1. For the broaching of steel, best results are obtained at
a Rockwell 14 to 30 R.C.
||2. Insufficient flow or wrong type of coolant.
||2. All major oil companies have qualified cutting
|3. Poor broach design.
||3. Inspect the broach closely and sharpen if
||Check 1 to 6 in "Workpiece Stuck on
7. Interrupt cutting stroke.
|7. Stroke of machine should be adjusted so that
broach never leaves guides.
||1. Too few teeth in contact with workpiece simultaneously.
||1 Check pitch of broach with "Pitch formula."
||2. Excessive hardness of workpiece.
||2. It is sometimes possible to eliminate chatter
by changing the rate of travel, coolant, face
|Broaching Drifting In Cut
||1. Poor sharpening.
||1. Check broach carefully and resharpen if necessary.
||2. Broach not properly supported especially
in a horizontal machine.
||2. If internal broaching on a horizontal machine
rear support may be required.
|3. Variations in hardness workpiece.
||3. In broaching steel, best results are obtained
at a Rockwell hardness of 14 to 30 RC
|4. Not enough broach teeth in action simultaneously.
||4. Check pitch of teeth using "Pitch formula."
|5. Body diameter too small.
|Scores On Broached Surface
||1. Poorly ground chipbreakers.
||1. Change design of chipbreakers on last few
roughing teeth or semi-finish teeth.
||2. Metal pickup.
||2. Remove any pickup. Check tooth profile design.
|3. Burrs left on cutting edges from sharpening.
||3. Grinding burrs must be removed after sharpening.
|Rings In The Broached Holes
Or On The Surface Of The Workpiece
||1. Uniform pitch of teeth may cause surging.
||1. Sometimes the use of staggered pitches eliminates
||2. Back-off clearance may be excessive.
||2. Sheer cutting teeth on surface broaches help
|3. Burrs left on cutting edges after
||3. After sharpening burrs must be removed from