How to choose a circular saw: blade diameter and power source

For cutting wood and panels on site, a portable circular saw with a 165-190 mm blade covers most jobs. Cordless is more convenient on scaffolding and where there is no mains power, corded copes with long, repeated cuts. If instead you always cut in the same place and want a workbench, you need a table saw. Before choosing, look at three numbers: blade diameter (from 140 to 270 mm in the collection), maximum cutting depth at 90 degrees (from about 25 to 100 mm) and weight.

Types

• Corded portable circular saw: powerful, with no runtime limits. There are many models for wood, such as the Makita 5103R or the 5008MGJX.
• Cordless circular saw: no cable, at 12, 18 or 54 V in the data. An example is the HD18 CS Milwaukee or the M18 BLCS66.
• Plunge saw (plunge-cut saw): runs on a guide rail and plunges into the workpiece, for precise cuts in panels. This is the case with the M18 FPS55 Milwaukee.
• Table saw: a stationary machine with a work surface, for repeated cuts to size, such as the Makita 2704N. The catalogue also includes combination saws.
• Band saw: a continuous blade for curved cuts or larger sections.
• Table accessories: support legs, workpiece supports, pivoting squares.

How to choose by job

Features to look at

• Blade diameter: the data show 140, 165, 184, 190, 210, 235, 260 and 270 mm. Small blades are lighter and easier to handle, large ones cut deeper.
• Cutting depth at 90 degrees: from about 25 to 100 mm. It must exceed the thickness of the workpiece, and when you tilt the blade the depth drops.
• No-load speed: from 3,500 to 6,000 rpm. A high speed gives cleaner cuts in wood; the number alone is not enough, the blade fitted matters too.
• Voltage: 12, 18, 20 and 54 V for cordless machines; 230 V for corded ones. Check that the battery you have on site is the same as the system.
• Weight: 3.4-3.8 kg for portable saws; table saws reach 14.5, 24 and 70 kg. For working a long time on scaffolding, every 100 g counts.
• Noise: sound power ranges from 99 to 109 dB(A) and pressure from 88 to 98 dB(A). Ear defenders are needed in any case, but the figure helps you compare.

Common mistakes

• Choosing a blade that is too small: then the cut does not go through the thickness. Check the depth, not just the diameter.
• Fitting the wrong blade for the material: wood, panels and metal need different teeth. A wood blade on metal is ruined.
• Forgetting the bevel angle: for 45-degree cuts the usable depth drops.
• Buying the battery without looking at the system: if you already have batteries of one brand, it pays to stay with the same voltage.
• Forcing the cut or locking the lower guard open: this is the cause of the most dangerous kickbacks.

Frequently asked questions

Battery or corded?

Cordless if you work at height or without sockets, corded if you cut a lot and for long periods. For short, occasional cuts the difference is barely noticeable.

Which blade do I fit to cut panels?

A blade with many teeth gives the cleanest cut on coated panels; for quick cuts in solid wood, wider teeth are fine.

Is a plunge saw better than an ordinary circular saw?

It is not better, it is different: it is for precise cuts with a guide, for example on panels or doors. For carpentry cuts the ordinary circular saw is faster.

Do I need dust extraction?

If the machine has the connection, using it reduces dust. On site it is always worth it.

You will find models, blades and accessories in the circular saws, band saws and table saws collection: for advice on the right model, ask the AMES technicians for a quote.