A hacksaw is a handheld tool used to cut through materials like plastic tubing and metal pipes. Its cutting mechanism is provided by removable blades which feature sharp teeth along their outer edge. Before using a hacksaw, it is important to understand how the tool works, as failure to do so can lead to broken blades, wasted materials, and even injury.
In most cases, a hacksaw consists of a metal frame that resembles a downward-facing U. A handle of plastic, wood, or metal is typically affixed to one end of the frame. The frame’s ends feature adjustable pegs that can be tightened to secure a blade in place, and loosened to remove it.
Hacksaw blades are long, thin strips of hardened steel that feature a row of teeth along their cutting edge. Each end of the blade is punched with a small hole that fits onto the saw frame’s pegs. Most blades range in length from ten to 12 inches (25.4 to 30.48 cm), although six-inch (15.24 cm) blades can be purchased to fit smaller hacksaw models.
The number of teeth on a blade can also vary. This figure is expressed as teeth per inch (TPI). Most hacksaw blades have a tooth distribution that ranges from 14 to 32 TPI. Tool experts recommend that, while cutting, at least two teeth should be in contact with the material being cut at all times. Thus blades with a higher TPI are best suited to small, thin materials, while those with a low TPI are useful for materials that are large or thick.
When cutting with a hacksaw, the user should first select an appropriate blade and, using the blade pegs, fasten it onto the saw’s frame. The object to be cut should be secured in place, ideally with a vise or similar device. To begin sawing, the user should center the tool’s teeth on the cutting target. He should then make long back and forth strokes with the saw, using slight pressure if necessary, until the desired cut has been achieved.
To avoid broken tools, wasted material, and injury, hacksaw users should follow a few basic operating principles. First, all body parts should be kept away from the saw’s blade while in use. Further, the item being sawed should be firmly secured into place to prevent it from slipping and potentially striking or cutting the user. Finally, to prevent breakage, saw blades should be oiled before use and thoroughly cleaned afterward.
By M.C. Huguelet