TM 9-3405-205-14 & P
3. Operation
The speed should be turned to maximum. Hand feed is satisfactory for friction sawing if a wood pusher stick is
used as a safety precaution. Friction sawing of thin material is so rapid that generally hand feed is used. The feed
rate is usually limited only by the operator's dexterity. For straight cuts only a guide is needed. The standard
angle plate can be used or a bar of steel clamped to the work table the desired distance from saw band by means
of the universal clamps.
**IMPORTANT
During friction sawing an extremely sharp burr is produced on the workpiece. Handle with care. Because friction sawing
is a dry operation, the dust and fine chips may be objectionable. If much of it is to be done in a general shop area, simple
screens can be erected to keep the dust away from other operations. Friction sawing is so fast that work handling may
require greater time than sawing.
iiMaterial to be sawed should not exceed 3/16" in thickness. Most steel alloys are within the low melting point range
and lend themselves to the friction sawing process. Annealing is not necessary since Rockwell hardness does not make
an appreciable difference in friction sawing. The heat penetration into the side wall of the finished cut is almost negligible.
If the cut is made too slowly, however, greater penetration will result. The most striking applications of friction sawing will
be found in the cutting of stainless steels and armor plate which sometimes cannot be cut by any other method. Materials
such as glass, plastics, brass and bronze, magnesium and aluminum do not lend themselves to friction sawing.
FRICTION SAWING CHECK LIST
OPERATIONS
1.
Check advisibility of friction sawing the material.
2.
Select saw blade.,
3.
Install roller guides.
4.
Install and tension saw band.
5.
Select and mount tooling, if any.
6.
Set band speed (5200 FPM).
7.
Do not use coolant. Determine fastest practical feed methods.
FOR BEST RESULTS
1. Alter speed for best cutting rate and least high speed vibration.
2: Wear safety glasses and gloves. Set up screen to keep chips and dirt in area.
3. Keep work surface of machine clean.
4. Arrange work handling for efficient production.
BAND SAW BLADES
Four basic differences are involved in band saw blade design and these E re the number of teeth
(pitch), the tooth form, the set of the teeth and blade material.
The tooth forms are shown in figure 6.In general, the thicker the workpiece, the coarser the pitch of the blade used.
Follow he recommendations shown in figure 6 or pitch selection. Set patterns used on band saw blades are shown in
figure 7. The
raker set is
one of
the two most commonly used in
metal cutting. The
other is
the wavy set used where the
cross section of the work changes such as in cutting of pipe tubing and structurals. The straight set is used for blades to
cut wood and plastics. Band materials may be carbon steel, carbon steel with a high speed welded edge, carbon steel
with carbide tips, carbon steel with diamond tips, and high speed steel. Caution: Never run a high speed blade over 500
SFM.
17