NOTE: The cutting technique for concrete is very different from a wood cutting chain saw, where cutting
with the nose of the guide bar must be avoided. With a wood cutting chain saw, the hook-shaped saw
teeth can easily grab the wood fibers, leading to a kickback hazard. Diamond segments which are
cutting concrete do not behave in the same way. They simply abrade the workpiece without grabbing so
aggressively. Still, always hold the saw firmly with both hands to resist kickback forces.
c Beginning the cut:
With the chain running at full speed, slowly approach the workpiece with the nose of the guide bar and
plunge in. Hold the saw as straight as possible.
Start by making a shallow, 10 to 20mm outline cut along the entire cutting line with the nose of the guide
bar. Then plunge in deeper and complete the cut.
While cutting, keep steady feed pressure on the tool to prevent the chain from chattering and bouncing.
Use enough pressure so that the motor audibly slows by about 20-30%. This will keep the diamonds
sharp. Use the bumper spike for leverage to assist in keeping pressure on the cutting face.
d Square cut-outs:
When performing large square cut-outs, after the initial shallow outline cut, carefully hold the saw as
squarely as possible and plunge cut each of the corners all of the way through.
Make the bottom horizontal cut first, then drive some wedges into kerf of the bottom if the cut section is
large and heavy. Next, perform the 2 side vertical cuts. Make the top horizontal cut last.
This cutting sequence will avoid the chain being pinched by the workpiece.
WARNING: Ensure that appropriate bracing is in place to control falling of the concrete as the final cut
is completed. Concrete is extremely heavy and could lead to severe injury if it falls in an uncontrolled
manner.
e Pipe cutting:
When cutting a concrete pipe, support the pipe so that it will not pinch the chain. Plunge straight
through the pipe, leaving a tab of uncut material at the very top, which will keep the pipe stable while
cutting. Cut this tab last to complete the cut.
WEARING PARTS
1.
Diamond Chain
The diamond segments will wear away with normal use. In addition, the chain itself will stretch due to
accumulated wear of each joint of the chain. Inspect each segment of the chain before each use, noting
any segment damage or undue wear.
2.
Guide Bar
The guide bar rails will wear from abrasion with the chain. If the saw tends to cut to one side, the rails
have worn unevenly. The guide bar rails can be re-squared by carefully sanding on a bench mounted belt
sander. If the chain’s drive links are touching the bottom of the guide bar grooves, the guide bar must be
replaced. Running a good chain on worn out guide bar will prematurely wear out its drive links and the
motor will overload easily from the excessive friction.
Extra life can be had from the guide bar by flipping it over to the other side, since the bottom wears faster
than the top. It is a good practice to flip the guide bar each time you replace a chain. Generally, the guide
bar will need to be replaced after about 3 chains.
