Circular saw blade

Circular saw blade: a cutting tool with peripheral teeth used for wood, metal, and masonry, made from high-speed steel or carbide.

About this subject

Circular saw blades are toothed discs designed for cutting wood, plastic, non-ferrous metals, and masonry. Invented in the late 18th century, they became widespread during the Industrial Revolution when sawmills adopted steel discs powered by steam or water. Modern professional blades are typically made with a steel body and carbide-tipped teeth (tungsten carbide), offering superior durability and wear resistance.

Common diameters range from 150 mm to 600 mm, with tooth counts tailored to specific tasks: 24 to 40 teeth for ripping lumber, and 60 to 80 teeth for fine cuts on plywood and laminates. For masonry and tiles, diamond blades are used, featuring industrial diamond segments sintered into the rim. Tooth geometry also varies: positive rake angles cut wood efficiently, while negative rake angles are used for metals to prevent workpiece kickback.

Safety regulations such as OSHA in the U.S. or NR-12 in Brazil mandate blade guards, riving knives, and anti-kickback devices. Regular sharpening or replacement is essential, as dull blades cause motor overheating, material burn, or accidents. Leading brands in the global market include Bosch, Makita, DeWalt, and Freud, with prices ranging from $10 for basic blades to over $100 for high-end professional models.

Frequently Asked Questions

What is the difference between a circular saw blade for wood and for metal?

Wood blades have positive rake angles and fewer teeth, while metal blades have negative rake angles and more teeth. Metal blades are often made of high-speed steel (HSS) or specialized carbide.

How do I know when to replace the blade?

Signs include burn marks on cut edges, increased effort from the saw, excessive vibration, or visibly damaged teeth. Check sharpness every 10 hours of heavy use.

Can I use a circular saw blade on a table saw?

It depends on diameter and arbor hole size. Table saws usually accept 250 mm to 300 mm blades with a 30 mm or 5/8 inch arbor. Always verify your tool's specifications.