Circular Saw

A circular saw is a hand-held power saw that drives a round toothed blade through lumber and sheet goods. It is the primary cutting tool for framing and general carpentry on site.

Models

3.3–8.3 in (85–210 mm)

Blade diameter

Brands

Cat classes

Pick a size class — capacity and reach differ across the range.

How it works

The motor spins the blade, and a spring-loaded lower guard retracts as the shoe rides the workpiece and covers the blade again after the cut. Depth and bevel adjustments on the shoe set how much blade is exposed and at what angle. Sidewinder models place the motor beside the blade; worm-drive models put it behind for more torque and a longer body.

Types & variants

Sidewinder saws: The common inline-motor layout, light and compact.
Worm-drive saws: Gear-driven saws with high torque, favored for heavy framing.
Compact cordless saws: Small-blade battery saws for sheet goods and light framing.
Metal-cutting saws: Lower-RPM saws with carbide blades and chip containment for steel.

Key specifications

Specification	Typical range	What it means
Blade diameter	3.3–8.3 in (85–210 mm)	Sets depth of cut; the full-size 7-1/4 in class cuts nominal two-by lumber at any bevel.
Weight	2.6–11.7 lb (1.2–5.3 kg)	Compact saws reduce fatigue on repetitive sheet cuts; heavier saws track better in thick stock.
Bevel capacity	Varies by model	Allows angled cuts for rafters and roof work without a second tool.

How the industry sizes it

Models are differentiated by blade diameter and drive layout. Compact saws with blades under 165 mm excel at panel processing and battery work, while full-size saws remain the framing default. The recorded no-load speed range for this class includes implausible high values and should not be relied on.

Applications

Framing cuts in dimensional lumber
Breaking down plywood, OSB, and other sheet goods
Deck, fence, and formwork cutting
Rafter and stair stringer bevel cuts

Safety & operation

Kickback from a pinched blade is the main hazard; supporting the work so the kerf opens, and never removing the lower guard, are the core controls.
Set blade depth so teeth clear the stock by about a quarter inch, reducing exposed blade.
Wait for the blade to stop before setting the saw down, and keep the cord clear of the cut line.

Standards & certifications

OSHA · 29 CFR 1926.304: Woodworking tools: guarding and operating rules for hand-fed circular saws.
UL · UL 62841: Safety standard for hand-held motor-operated electric tools.

Frequently asked

What blade size is standard?

7-1/4 in (about 184 mm) is the framing standard, cutting two-by lumber at 90 and 45 degrees; compact cordless saws commonly run 6-1/2 in and smaller.

Sidewinder or worm drive?

Sidewinders are lighter and quicker to handle; worm drives deliver more torque and blade-left visibility, at a weight penalty.

Why does the saw kick back?

The blade binds in a closing kerf, usually from unsupported stock sagging, a dull blade, or twisting off the cut line. Proper support and a sharp blade prevent most events.