Japanese Saw Basics: A Complete Beginner’s Guide

April 7, 2026

Japanese saws allow for incredibly precise and beautiful cuts thanks to their unique "pull-to-cut" mechanism.
In this guide, we will explain four essential elements you need to know to truly understand the magic of Japanese saws: TPI, Blade Thickness, Kerf, and Set.

Whether you are a beginner or a seasoned woodworker, feel free to skip to the section that interests you most!

1. What is TPI (Teeth Per Inch)?

TPI stands for "Teeth Per Inch" (the number of teeth per 25.4mm of the saw blade). It is the standard metric used to determine how fine or coarse a blade is.

In Japanese saws, the TPI is explicitly designed based on the intended purpose:

・Crosscut Blades (Higher TPI): Designed to sever wood fibers cleanly, requiring finer, sharper teeth.
・Rip Cut Blades (Lower TPI): Designed to act like tiny chisels, efficiently clearing wood along the grain.

Examples from the SUIZAN Lineup:

2. The Advantage of an Ultra-Thin Blade

One of the most defining characteristics of a Japanese saw is that the blade is exceptionally thin compared to Western push saws. This is only possible because the blade operates under tension during the pull stroke.

Benefits of a Thin Blade:
・Dramatically less cutting resistance.
・Allows for highly accurate cuts with very little effort.

⚠️ A Word of Caution:
Because the blade is so thin, it is delicate. Applying forceful pressure on the push stroke can easily bend or kink the blade. It is crucial to let the tool do the work and only apply force when pulling.

3. Understanding "Kerf" (Cutting Width)

The kerf (the width of the cut made by the saw) is closely related to the blade's thickness. Because Japanese saws have such thin blades, their kerf is exceptionally narrow.

A narrow kerf provides several massive advantages:

・Removes the absolute minimum amount of wood.

・Prevents the blade from binding, ensuring a smooth stroke.

・Reduces user fatigue, requiring far less physical power.

・Allows for highly accurate cuts, even over long periods of work.

・Perfect for precision woodworking and complex joinery.

This narrow kerf is one of the primary reasons Japanese saws are renowned worldwide for "delicate and precise work."

4. What is "Set" (Alternating Teeth)?

The "Set" refers to the way the saw teeth are slightly bent outward, alternating left and right.

Having a "Set" provides the following effects:

・Creates a kerf (cut width) that is slightly wider than the blade itself.

・Reduces friction between the blade plate and the wood, making cutting smoother.

・Effectively clears sawdust out of the cut.

The Exception: Flush Cut Saws (No Set)

Unlike standard saws, a Flush Cut Saw (Kugihiki) has no set on its teeth. Because the teeth do not protrude past the blade plate, you can lay the blade completely flat against a surface to cut protruding dowels or pegs without scratching the surrounding wood.

Examples of SUIZAN Flush Cut Saws:

・Flush Cut Saw 5-inch: Blade Thickness & Kerf = 0.012 inches (0.3mm)

・Flush Cut Saw 7-inch: Blade Thickness & Kerf = 0.008 inches (0.2mm)