General Hand Tools Used in the Workshop

A hacksaw is a hand tool used to cut metal bars, pipes and sections. It consists of a frame holding a thin, hardened steel blade under tension.

Parts

  handle                       adjusting screw
   ___      ___________________   (wing nut)
  /   \____|                   |_____
 |    ____ |   blade  ----------     |
  \__/    |___________________|_____/
      frame (adjustable or solid)  pins at both ends

• Frame: adjustable (fits blades of 250 to 300 mm) or solid.
• Blade: high speed steel or low alloy steel, 250 or 300 mm between pin holes, with teeth on one edge.
• Handle: pistol or straight grip.
• Wing nut: tightens the blade; two pins hold it with teeth pointing forward (away from the handle).

Selection of pitch (teeth per 25 mm)

Rule: at least three teeth must be in contact with the work at any time. Otherwise the teeth strip and break.

The teeth are given a set (wave or alternate) so the cut (kerf) is wider than the blade and does not bind.

Correct use

• Fit the blade with teeth pointing away from the handle and tighten it well.
• Clamp the work firmly near the cut.
• Cut on the forward stroke only; lift slightly on return.
• Use 40 to 60 strokes per minute with light, even pressure; use full length of the blade.
• Use a cutting lubricant for hard steels; start the cut with a file notch or at a small angle.

A file is a hardened steel tool with parallel rows of teeth used to remove small amounts of metal and finish surfaces.

Cuts of files

Grades (coarseness)

From coarse to smooth: rough, coarse, bastard, second cut, smooth, dead smooth. The bastard file is the most commonly used grade. The grade depends on the number of teeth per cm (pitch) and also on file length; a longer file has coarser teeth for the same grade.

Common file shapes and uses

• Flat file: general filing of flat surfaces, slightly tapered in width and thickness.
• Hand file: parallel in width, one safe (smooth) edge for filing near a shoulder.
• Round file: enlarging holes, filing curved surfaces and fillets.
• Half-round file: curved surface on one side, flat on the other; for concave and flat work.
• Square file: slots, keyways and square holes.
• Triangular (three-square) file: internal angles, sharpening saws, corners over 60°.
• Knife-edge file: acute angles and narrow grooves.

Care

Fit a handle; do not use a file as a lever or hammer; clean with a file card; keep it dry and away from other tools.