hacksaw

A hacksaw is a hand tool used for cutting metal and other materials. It consists of a slender blade mounted in a rigid frame, with a handle on one end. The blade is tensioned between the frame’s ends so it remains straight during cutting.

Blades are typically made of high-carbon steel, alloy steel, stainless steel, or bi-metal. They come in various tooth pitches (teeth per inch) to suit different materials and finishes. Coarser blades cut faster but produce rougher edges and are more durable, while finer blades yield smoother cuts on thin or hard metals. Common blade lengths are about 8 to 12 inches.

Applications include cutting metal such as steel bar, pipe, or angle stock; with suitable blades, plastics can also be cut. The operation involves guiding the frame with a steady back-and-forth motion, keeping the blade taut and perpendicular to the work. Cutting quality improves with proper clamping, moderate feed pressure, and blade lubrication when needed.

Variants include the standard drop-forged frame hacksaw, pistol-grip or adjustable-frame variants, and automatic hacksaws used in industry. Blades are easily replaceable, and frames may be designed for different lengths or for easier reach in tight spaces.

History: The hacksaw’s modern design with a replaceable blade and tensioned frame developed in the 19th and early 20th centuries and has since become a standard tool in metalworking, plumbing, and fabrication.