A hacksaw is a saw designed primarily to cut metal, plastic and other relatively thin, hard materials. It is available as a manual framed saw and as powered variants that use similar blades in a reciprocating or orbital motion. The tool is defined by a narrow, replaceable blade held under tension in a rigid frame and a handle to guide the cut.
Characteristics and components
Typical parts include the frame, blade, handle and a tensioning mechanism. Blades are thin, replaceable and sold in different teeth-per-inch (TPI) ratings: high TPI for thin or hard materials, low TPI for thicker stock. Common blade materials include high-speed steel and bi-metal constructions. The frame may be adjustable to accept various blade lengths; compact "mini" frames exist for confined spaces.
History and development
Hacksaw designs emerged alongside industrial metalworking in the 19th century, when craftsmen needed a simple, durable tool to cut bars, bolts and pipe. Over time blades and frames were refined for easier replacement and better tensioning; powered reciprocating saws later adapted the same blade form for faster work.
Uses, technique and safety
Common tasks include trimming bolts, cutting conduit, shaping sheet metal and slicing plastic pipe. Good practice recommends clamping the work, using the appropriate TPI, keeping the blade tensioned and applying cutting lubricant when sawing metal. Operators should wear eye protection and follow typical workshop safety rules.
Variants and distinctions
- Manual hacksaws — inexpensive, portable and versatile for small jobs.
- Electric or pneumatic reciprocating hacksaws — suited for production and heavy cuts.
- Not to be confused with coping saws or jigsaws, which use different blade forms and are intended mainly for wood or fine shaping.
Because blades are consumable, choosing the correct tooth pitch and replacing worn blades are key to efficient, accurate cutting.