|New B. M. T. Saw
The new patent tooth B. M. T. Saw, devised by Warren Bundy,
Minnesota City, Minn., and manufactured by the
Montague-Woodrough Saw Company, 211 and 213 Randolph Street,
Chicago, Ill., is represented in the accompanying illustration.
As shown in the cut, the teeth are arranged in sets of three
each and after each set is a recess or gullet for the reception
of the sawdust liberated.
There are two distinct kinds of teeth in each set, two cutting
teeth and one clearing tooth. The cutting teeth are made with
the cutting edge on the outer edge of each tooth, and are
arranged in step form, with a rise from the body of the saw of
about 45 degrees. The cutting edge is on opposite sides in each
pair of teeth, so that the bevels face each other, thus making
two parallel gashes in the wood.
The purpose of the clearing tooth, which is slightly below the
points of the cutting teeth and which is formed like a common
mortising chisel, with its cutting edge at a right angle to the
gash, is to clear away the wood between the two gashes into the
recess or gullet before it, thus leaving the next pair of
cutting teeth free from obstruction to their work. On drawing
the saw back into the gash, the sawdust is pushed out of the
gullet, leaving it clear for the next stroke.
The sharp chisel
edge of the cutting teeth is referred to as leaving the sides of
the wood as smooth as though planed, and, as little set is
required, the saving of material is referred to as important,
while the absence of roughness and loose fibers lessens the
friction, enabling the saw to work successfully with much less
power than the V-tooth saw.
With this construction it is claimed that the saw will cross
cut, rip or cut in a miter box with equal facility one-third
faster than any saw now made specially for either of these
purposes. Alluding to circular saws made with teeth of this
pattern, the manufacturers refer to the smoothness of the cut,
the saving of material lost in dressing, and the length of time
that they will run without filing. They point out that the use
of cross-cut and ripping tables is made unnecessary, and that no
time need be wasted, as at present, by substituting one saw for
In jig saw work it is stated that the material is cut so smooth
that mouldings, &c., are ready for use when they leave the saw.
The adaptation of this style of tooth to hand saws is also
It is also pointed out that saws with this pattern of teeth are
easier to file and below the bevel of the cutting teeth in back.
After all the clearing teeth have been filed the cutting teeth
are filed to a point one at a time, so that all can be brought
to an exact level. When this is done an oilstone laid flat on
the side of the saw and run up and down a few times will reduce,
it is said, any irregularity in the set and give smooth cutting.
The set is given by placing the tooth on a piece of flat steel
with a slight bevel on the edge and striking it with the pein of
a hammer in such a way as to set only the front or cutting edge,
where in the ordinary saw the whole tooth is turned.
The company has a special saw-set made for this purpose, which
is referred to as doing its work exactly. The circular issued by
the company gives a full description of this saw, and
illustrates the manner in which it is filed, and the price list.
Building, Vol. 1889-Vol.11, (New York: David Williams)