Power ToolsCutting tool
Circular Saw
A toothed blade spinning on a vertical arbor, cutting sheet goods and solid stock to length and to width. The default first cut in timber and board.
What it does
- Ripping and cross-cutting sheet goods
- Cutting solid timber to length
- Trimming to a marked line with a straight edge
Materialswhat it is used on
All materialsWhat to look forthe judgement calls, before the spec sheet
- Blade tooth count sets the trade-off: a low count cuts fast and leaves a rougher edge, a high count is slower and cleaner. For sheet goods where both faces matter, the high count is the one that saves the second operation.
- Blade diameter decides the maximum depth of cut at 90°, and depth at 45° is roughly two thirds of it. If the job is a bevel in thick stock, check the bevel figure rather than the headline one.
- A saw with a guide rail cuts a repeatable line without a separate straight edge, which is the difference between one accurate cut and ten that need sanding.
Misuse and safetythe ways this tool causes rework
- Kickback happens when the blade is pinched. Support the offcut so it cannot close on the blade, and never cut with the workpiece bridging two supports.
- Blunt blades burn rather than cut. The smell of scorching timber means the blade is working harder than the motor, and the cut is no longer straight.
Projects that call for itand what it is doing on each one
All projectsFrequently asked questions
How deep will a circular saw cut?
At 90° it is the blade's maximum depth of cut; at 45° it is about two thirds of that, because the blade is presenting a longer edge to the work. The two figures are printed separately on the machine for that reason.
Can it cut metal?
Only with a blade made for it, and the blade is the whole answer — a wood blade on steel is dangerous, and hot metal chips are a different hazard from sawdust. Most metal cutting is done with an abrasive disc on an angle grinder instead.