- Q.We have an
ongoing debate on our job site concerning the proper way to
adjust the blade depth on a circular saw. One group says that
the blade should be set just slightly deeper than the thickness
of the material being cut. The other group says that the blade
should usually be left at the maximum depth, since this
allegedly gives better control, is less stressful on the saw,
and gives the longest blade life. Who’s right?
A.Steve Dassoulas, a
technical manager at DeWalt, responds: Both groups are
partly right. It really depends on what the user wants —
better finish or better blade life. For a given cutting speed,
setting a deeper cut depth does increase blade life. A deeper
cut is less stressful on the saw and the blade, because fewer
teeth are in contact with the wood at any one time. The
downside to this approach is that it increases the entry and
exit angles of the teeth with the wood, which reduces the
quality of cut finish. So if it’s finish you want, adjust
the blade depth to slightly more than the thickness of the
material.
Minimizing blade depth also improves safety. Keep in mind
that kickback can occur when the back of the blade gets
pinched. With less depth of cut, less blade area is exposed to
the wood, decreasing the chance of kickback. Because there is
always a risk that an operator can accidentally get in the way
of the blade, reducing the amount of exposed blade improves
safety. It also decreases the likelihood that the saw will cut
unknown pipes or wires that may be hidden behind the material
being cut.
For the best quality of finish and the greatest level of
personal safety, set the blade so that the gullet of one tooth
is slightly exposed beyond the thickness of the material being
cut.