What does the TPI rating on a reciprocating saw blade indicate?

The TPI rating on a reciprocating saw blade stands for "teeth per inch." This measurement indicates how many teeth are present on the blade for every inch of its length. A higher TPI generally means a finer cut, as more teeth provide better control and smoother finishes, while a lower TPI allows for faster cutting through thicker materials, as there are fewer teeth engaged with the material. Understanding the TPI is essential for selecting the right blade for different cutting applications, whether for metal, wood, or other materials.

The other options do not accurately capture what the TPI rating signifies. Blade thickness pertains to the durability or rigidity of the blade, length relates to the overall size which does not directly affect cutting efficiency in the context of TPI, and the type of materials a blade can cut is more closely related to the design, material, and specific teeth format rather than the TPI rating itself.