Circular saw RPM calculator
Same physics as a drill, much bigger diameter: pick the material and blade size, and get the blade speed your cold saw should turn.
Why circular saws turn so slowly on steel
The formula is the familiar n = (Vc × 1000) / (π × Ø) — but a 300 mm blade has an enormous circumference, so even a healthy cutting speed works out to surprisingly few revolutions. Steel on a 300 mm cold saw lands around 100 rpm; that slow, powerful rotation is exactly what distinguishes a metal cold saw from a wood saw spinning at 4000+.
Why is the aluminium value so much higher?
Non-ferrous saws for aluminium run at wood-saw-like speeds (Vc around 400 m/min with carbide blades and lubrication) — aluminium cuts easily and carries heat away quickly. Never use that speed on steel with the same blade.
Which blades do the default speeds assume?
Carbide-tipped cold saw blades. HSS circular saw blades run considerably slower — roughly a third to half; just edit the Vc field and the rpm follows.
Are these values safe to use directly?
They are starting values. Clamp the work solidly (a cold saw grabbing loose stock is dangerous), use the machine's vice, respect the blade manufacturer's maximum rpm printed on the blade, and use coolant or wax stick as prescribed.
Is my data sent anywhere?
No — this runs entirely in your browser with plain JavaScript. Nothing is uploaded.
