Jigsaw
What is a Jigsaw?
A jigsaw (also called a saber saw) cuts in a rapid up-and-down motion. The key to excellent results with a jigsaw is to match a specific blade to the type of material you'll cut: wood, metal, plastics, tile, etc. The blade package will indicate what material the blade cuts best.
Most blades are carbon steel, 2 to 3-1/2 in. long and either 1/4 in. wide for making tight radius cuts or 3/8 in. wide for general-purpose cutting. Six-teeth-per-inch blades cut fast but rough; finer blades with 10 or more teeth per inch deliver smoother cuts. Special toothless blades cut everything from leather to tile. When buying blades, consider investing in bimetal blades. They can last 10 times longer and are less likely to break. Most jigsaws accept blades with a 1/4-in. universal tang that locks into the blade clamp with a set screw. Some saws accept only specially designed blades (like bayonet-mount) from their own manufacturer.
Using a Jigsaw with Wood
Jigsaws are ideal for cutting curves and complex shapes in wood. They also work well for making short crosscuts on a board and finishing inside corner cuts that you start with a circular saw. Jigsaws are not good for making fast, long, straight cuts. Use a circular saw instead. When cutting wood, follow these guidelines:
Jigsaws work best for cutting softwood that's no more than 1-1/2 in. thick and hardwood up to 3/4 in. thick. Jigsaw blades tend to bend when cutting curves in thicker boards, leaving a beveled edge rather than a square one. To keep the cut square, use a sharp blade and avoid forcing the saw through the cut.
To “plunge cut,” that is, make an entry saw cut into the middle of your wood, tip the jigsaw so that the blade is parallel to the workpiece and the saw's weight rests on the front lip of the shoe. Start the saw at maximum speed, tilt the shoe and steadily lower the stabbing blade into the wood. Try to reserve plunge-cutting for rough work so that an errant blade doesn't slash and mar expensive woods. In fragile material, drill a 1/2-in. starter hole to safely position the blade for a cut.
For quick cutting, use a coarser blade. But note that the coarser the blade, the more sanding later.
Most wood-cutting blades for jigsaws are designed so the teeth cut on the upstroke. For fine work demanding less chipping—in wood veneers, for example—choose a “downstroke-cutting” blade. An alternative is to place painter's or masking tape on the cutting line path before drawing on the pattern line.
Using a Jigsaw with Metal
With the proper blade, jigsaws can cut through wood with embedded nails, 1/8-in. mild steel, no-iron pipe and sheet metal up to 10 gauge thick.
For cutting sheet metal, choose a finer blade with 21 to 24 teeth per inch. To avoid shredding sheet metal or raising a lot of edge burrs, tightly sandwich the metal between two layers of thin plywood. Cut metal plate and pipe on low speed. For pattern cutting, drill blade starter holes instead of making plunge cuts. Expect it to take a while to cut through the sandwich. When cutting over a workbench or sawhorses, prop the sandwich on rails for adequate blade clearance below.
Features such as higher saw power, long blade stroke, variable speeds and orbital cutting action are all pluses for cutting metals, and are found on more costly jigsaws. Saws that are equipped with vacuum hose connections to keep the pattern cut sightlines free of dust also are a plus. Cutting pipe and mild steel plates wears out blades fast. Keep plenty of blades on hand, select a coarser blade (like 14 teeth per inch) and lubricate the saw cut with cutting oil.
Source: Family Handyman