Hack Saw Tips
by Sahar Conor
A hacksaw equipped with the correct blade can cut practically any metal you will encounter in shop work. To avoid breakage, draw the blade taut in the frame to prevent flexing.
Blade choice depends on the material and its thickness. In general, use coarse teeth on thick metal, progressively finer teeth on thinner metal. At least two teeth should always be in contact with the material, so a thin section can't hook between teeth and break them. When you are cutting very thin stock, tip the saw so that the teeth contact a part of the surface instead of the edge.
Standard high-speed steel blades can handle most of the cutting chores you are likely to be faced with. If you want blades that will perform well for a longer time, use molybdenum alloy blades; they cost a little more than standard blades but can last 'up to 10 times as long. For the toughest cutting jobs, use a tungsten alloy blade. Mount the work in a vise or jig so it cannot shift and break the blade. Grip the handle of the saw in your right bawl, hold the front of the frame with your left band, and make slow strokes, using moderate down pressure on the forward cutting stroke and almost no pressure on the back stroke. Use as much of the blade length as you can for maximum cutting speed and minimum tooth wear.
If available, use blades with wavy set teeth for thin stock, regular set for general work. Blades should have 14 teeth per inch to cut bronze, aluminum, copper, brass, cast iron, or machine steel more than 1-inch thick; 18 teeth for copper, aluminum, bronze, high-speed steel, tool steel, and annealed steel ‘4 to l-inch thick; 24 teeth for to 1/4-inch iron, steel, wrought iron pipe, brass or copper tubing, drill rod, and items such as electrical conduit; and 32 teeth for the same materials 1/4-inch thick or less.