by Lowell Freeborn 

The two major problems are galling or sticking of the aluminum to the saw blade, and sawing pieces of aluminum with improper clamping.  Refer to our Saw Blade Articles Index for more articles on Saw Blades. 

Galling 

If a saw is galling with aluminum, there is only one reason, inadequate and improper lubrication. Do not use water soluble oils mixed 50 parts water to 1 part oil.  This mixture may prevent rust and work as a coolant, but it does not lubricate.  Mix not more than 5 parts water to 1 part oil.  If galling still occurs, mix 2 or 3 to 1.  There are a lot of applications that require better lubrication than water soluble products provide.  A good grade cutting oil or sulphur base oil may be needed.  The method of applying the lubricant is also very important. Don't try to lubricate into the rim of the saw.  The fan action of the teeth blow it away. Put the lubricant on both sides of the saw.  This will allow it to oil the side of the saw and feed out to the teeth by centrifugal force.

Clamping

The cutting problem can be dangerous if not handled properly. The biggest problem is holding the material being cut. Some people will fix a solid stop on the machine, particularly radial arm and chop saws, and then proceed to cut the piece that is against the stop without clamping it.  The saw will cut through the part just fine, but when it is returned through the cut is where the danger lies.  The part is wedged between the stop and the saw.  If it moves slightly, the teeth will grab it and turn it until it either breaks the saw or it flies through the air like a bullet.  If you see someone cutting like this, clear the area and run like mad.