model t23108 (mfg. since 7/10) -17-
Chain Pitch
= This Distance/2
figure 15. Chain pitch.
Chain gauge: the chain gauge is the thickness
of the drive link tang (see figure 16) where it fits
into the guide bar groove. the guide bar groove
must match the width of the chain gauge.
Chain gauges for handheld chain saws range
from 0.050" for smaller chains to 0.122" for larger
ones.
Drive Link
Tang
Chain
Gauge
figure 16. Chain gauge.
Chain Pitch: the distance between any three
consecutive rivet centers divided by 2 is known as
the chain pitch (see figure 15).
the chain pitch is the same for all links in the
chain. the smallest chain pitch for handheld chain
saws is 1⁄4", with 3⁄8" and 0.325" being the most
pop ular.
Top Plate Angle: the profile of the cutter link is
shaped like a number "7", and is comprised of
the top plate and side plate (see figure 17). the
rake that the top plate angles back from the side
plate is called the top plate angle and is generally
25°–35°. this makes a sharp point that begins the
cut.
Top Plate
Cutting
Angle
(Top View) (Side View)
Top Plate
Angle
(Front View)
figure 17. Cutter link top plate angle and cutting
angle.
Top Plate Cutting Angle: the top plate cutting
angle (see figure 17) is a chisel-like downward
bevel on the underside leading edge of the top
plate that usually is 60°. the combination of this
cutting angle and the top plate angle ser ves to
remove wood chips from the kerf.
Side Plate Angl e: the ground angle of the side
plate leading e dge is instrumental in forming the
cutting point between the side and top plates. this
angle is the same as the top plate cutting angle,
which is typically 60° (see figure 18).
Side Plate
Angle
Gullet Angle
figure 18. Cutter link side plate angle, gullet,
and depth gauge.