Figure 5-3.—Tube cutting.
5. Tighten the drive screw 1/8 to 1/4 turn. Do
not overtighten the drive screw. Overtightening
can damage soft tubing or cause excessive wear
or breakage of the cutter wheel in hard tubing.
6. Swing the ratchet handle back and forth
through the available clearance until there is a
noticeable ease of rotation. Avoid putting side
force on the cutter handle. Side force will cause
the cutter wheel to break.
7. Tighten the drive screw an additional 1/8
to 1/4 turn and swing the ratchet handle back and
forth, retightening the drive screw as needed until
the cut is completed. The completed cut should
be 1/2 degree square to the tube centerline.
Figure 5-4.—Chipless cutter.
After the tubing is cut, remove all burrs and
sharp edges from inside and outside of the tube
(fig. 5-5) with deburring tools. Clean out the
tubing. Make sure no foreign particles remain.
A convenient method for cutting tubing with
a hacksaw is to place the tube in a flaring block
and clamp the block in a vice. After cutting the
tubing with a hacksaw, remove all saw marks by
filing.
Tube Bending
The objective in tube bending is to obtain a
smooth bend without flattening the tube. Tube
bending is usually done with either a hand tube
bender or a mechanically operated bender.
Figure 5-5.—Properly burred tubing.
5-5
