Diamond blades can be cheap to own but expensive to run unless you know what you are buying. So a quick primer on blades.<br>Diamond depth<br>Measured in thousands of an inch, the deeper the depth of diamond the longer blade wear you have. Cheap blades are about .187 to .250 of an inch of usable depth. More expensive ones run .280 to .350 of depth.<p>Deeper depths will give you a cheaper cost per inch foot of cut.*<p>Blade width, thinner blades are for block saws like .110 width hand saws need the .125 width. I like to use the .125 width on my block saws they seem to last longer.<p>DON'T USE .110 BLADES ON A HAND SAW!<p>Bonds, the softer the bond the harder the material to be cut.<br>Bonds are listed as a number, a number 2 bond is a soft bond used for cutting hard non abrasive material, a number 5 bond is for cutting cured concrete with medium abrasive material, number 7 bond is for cutting soft cured concrete and limestone, a number 8 or 9 bond is for cutting asphalt.<p>Checking your saws, you should check your saws at least twice a year if not more to make sure that they are running at the right speed, over speeding a blade can cause it to wear out your blades too fast and underspeed can cause it to slow down your cutting. Also break in your new blades by making a one(1" inch cut lowering the blade to that depth in about 4 or 5 seconds, cut about 15' at that 1" depth going about 5 feet per minute. This sets the blade and will give you longer life with it. When dry cutting remember to take the blade out of the cut every minute or so and run the blade for 5 or 10 seconds allowing it to cool down, heat kills more blades than misuse. If the blade overheats the will glaze over and quit cutting if this happens make some very shallow cuts in asphalt or cinder block, this will break the glaze and you can resume cutting.<p>* as long as proper usage is considered (don't run the blades in the cut for too long 40 to 60 seconds is long enough) <p>----------<br>paul<p><p><font size="1">Edited by: paul
This is good info. Thanks. How do you go about checking the speed of your saw, though. Seems that 5000+RPM would be hard to measure. Do you have some sort of tach you can hook up to the saw?
They make a hand held tach that fits the hub, they run about $75 check with your saw dealer.<p>----------<br>paul<br>
Stone, We figure about 4 years for our hand saws and 7 years for our block saws. We keep extra filters on hand and clean them once a week, having two saws on each trailer of each kind help in keeping a long life on our saws. biggest problem with hand saws is the cord pulling out of them when guys get in a hurry.<p>----------<br>paul<br>
I've started scheduling maintenance days - saturdays where I'll have a couple guys come in, about once a month, and clean all the (non-oiled) air filters, give the saws oil changes if needed, and just blow 'em all off with an air compressor. I guess I'll find out in time whether it's helping extend their lives.
