This prevents sagging of the file band at the point of
in contact, you must increase the feed pressure in
work. Use a similar support for a polishing band.
order to force the teeth into the material.
This support has a graphite-impregnated fabric face
Excessive feed pressure puts severe strain on the
that prevents undue wear on the back of the polishing
band and the band guides. It also causes the band to
band, which also is fabric.
wander sideways which results in off-line cutting.
Selection Of Saw Bands, Speeds And Feeds
Other points to consider in selecting a saw band
be cut, its hardness, and its toughness.
Saw bands are available in widths ranging from
1/16 to 1 inch; in various even-numbered pitches
BAND WIDTH AND GAUGE.--The general
from 6 to 32; and in three gauges--0.025, 0.032,
rule is to use the widest and thickest saw band that can
and 0.035 inch. The gauge of saw band that can be
do the job successfully. For example, you should use
used in any particular machine depends on the size
a band of maximum width and thickness (if bands of
of the band wheels. You cannot sucessfully use a
different thickness are available) when the job calls
thick saw band on a machine that has small
for only straight cuts. On the other hand, when a
diameter bandwheels; therefore, only one or two
layout requires radius cuts (curved cuts), select a band
gauges of blades may be available for some
that can follow the sharpest curve involved. For
machines. Generally, only temper A, raker set, and
curved work, select the widest band that will negotiate
wave set bands are used to cut metal.
the smallest radius required. The saw band width
Saw bands come in different forms for different
working. Some are furnished in ready made loops of
of the sharpest curve that can be cut with a particular
the correct length. Others come in coils of 100 feet or
width saw band. Note that the job selector illustrated
more from which you must cut a length and form it
into a band loop by butt welding the ends together in
a special machine. Later in this chapter, we will
explain the process of joining the ends and installing
Band tool machines have a multitude of band
speeds, ranging from about 50 feet per minute to
about 1500 feet per minute. Most of them are
equipped with a hydraulic feed which provides three
feeding pressures: low, medium, and heavy.
Success in precision sawing with's metal cutting
bandsaw depends on several factors: You must select
the correct saw blade or band, you must run the saw
band at the correct speed, and you must feed the work
to the saw at the correct rate. Many band tool
machines have a job selector similar to the one shown
should use, the speed at which you should operate the
machine, and the power feed pressure you should use
to cut various materials.
TOOTH PITCH.--Tooth pitch is the primary
consideration in selecting a saw band for any cutting
job. To cut thin materials, the pitch should be fine
enough so that at least two teeth are in contact with
the work; fewer than two may cause the teeth to snag
and tear loose from the band. To cut thick material,
you should not have too many teeth in contact with
the work, because as you increase the number of teeth