The quality of cutting highly depends on the jig saw blade used. Therefore, before buying the blade, you should always consider two factors. First and foremost, specify the type of material that is to be cut (wood, plastic, metal, etc.) and define the user’s needs (clean cutting, fast cutting, straight-line cutting or curvilinear cutting). If the customer wants to obtain highly cost-efficient cutting performance, the number of variables to consider when choosing the blade will be much bigger. The performance and useful life of a tool depends on the material from which the blade is made, the toothing, tooth geometry and tooth spacing.
Using the wrong one can potentially result in blunt or broken teeth. In extreme cases, the tool may crack.
Factor I – material from which the blade is made:
- HCS – jig saw blades made of carbon steel (for cutting soft materials).
- CrV – jig saw blades made of chrome-vanadium steel.
- HSS – jig saw blades made of high-speed, high-alloy steel (for metal cutting)
- HM – jig saw blades made of sintered carbide and bi-metal (for cutting extremely hard materials).
- BiM – bi-metal jig saw blades.
- HM/TC – jig saw blades made of carbon steel combined with sintered carbide (for cutting very hard materials).
Factor II – toothing:
- Wavy teeth for straight-line cutting.
- Sharpened teeth for precise cutting.
- Side set teeth for fast cutting.
- Side set, sharpened teeth for fast coarse cutting.
Factor III – tooth geometry:
- The angle of attack determines the cut depth. The bigger the angle, the deeper the blade can reach into the material. Therefore, blades with a small angle of attack are most suitable for cutting hard materials. Soft materials, in turn, are most effectively cut with blades with a greater angle of attack.
- Number of teeth per inch (TPI). The selection of teeth should be made based on the thickness and hardness of the material machined. Blades with a small pitch will produce a more precise cut of hard materials at a low cutting speed, while those with high pitch cut faster and are suitable for soft materials.
Factor IV – tooth spacing:
- The pitch, also called tooth spacing, can be either variable or constant. A constant pitch is a pitch where the spacing of all teeth is the same. A variable pitch is the pitch where the spacing varies. Variable teeth spacing is recommended for cutting materials of various hardness.
Good to know
Before buying a blade, check the handle type in the blade’s shank. Three shank types are available for sale:
- U-shank blades
- T-shank blades, which are the most widely used type, with one tongue.
- 2T-shank blades, with two tongues.