Bosch Professional GKS 18V-57 G – 18V Circular Saw

The GKS 18V-57 G from Bosch Professional cuts up to 57 mm deep – enough for most wood and sheet material jobs. Battery and charger are not included. The motor delivers 3400 rpm no-load speed, with constant speed under load. That means the saw doesn't bog down when you're cutting through a thick plank or plywood. The maximum cutting depth of 57 mm is achieved at 90°, while bevel cutting to 45° gives a depth of 42 mm. A rapid motor brake stops the blade immediately after switching off – you'll notice that in safety.

This circular saw works with the Bosch guide rail system, but is also compatible with rails from Mafell, Festool and Makita. Also on board: LED light, air blower, soft start and dust extraction connection. The included extraction adapter connects to a vacuum cleaner. The 165 mm saw blade (20 mm arbor) is a Standard for Wood – suitable for solid wood, OSB, plywood and MDF.

Constant speed under load is one of its strong points. Where many cordless saws drop off when cutting hardwood or thick boards, the GKS 18V-57 G holds its speed. The 400 W power (electrical) translates into a cut that stays clean and even. The no-load speed of 3400 rpm is sufficient for most cutting tasks. The maximum cutting depth of 57 mm at 90° is suitable for cutting 2x4 timbers or sizing furniture panels. Bevel cutting to 45° gives 42 mm depth – enough for mitre joints in sheet material.

The motor brake is a safety feature you won't want to miss. After releasing the switch, the blade stops within seconds. That prevents accidents when you put the saw down or change position. No spinning blade that could still cause damage.

Under the bonnet

• Power – 18V battery (Professional 18V System, sold separately)
• Max. cutting depth 90° – 57 mm
• Max. cutting depth 45° – 42 mm
• No-load speed – 3400 rpm
• Saw blade diameter – 165 mm (20 mm arbor)
• Weight – 5.70 kg (without battery)
• Noise level – 91 dB
• Soft start – gentle start-up prevents kickback

The base plate is made from stamped steel. That's a deliberate choice: steel is stiffer than aluminium and holds its shape under load. A warped base plate means crooked cuts – no risk here. The weight of 5.70 kg (without battery) is on the high side, but that's down to the sturdy construction. The soft start ensures the saw doesn't lurch when you switch it on. The spindle lock makes changing the saw blade easy: press the button, lock the spindle and swap the blade.

Dust extraction is standard. The included adapter connects to a vacuum cleaner. That keeps the workspace cleaner and extends the saw's life – less dust in the motor. The air blower blows sawdust away from the cut line, so you can always see where you're cutting. An LED light illuminates the workpiece in low light. Not a luxury on a building site or in a dark workshop.

The GKS 18V-57 G is built for wood and wood-based products. Solid wood, OSB, plywood, MDF – the Standard for Wood blade can handle it. The 165 mm blade with 20 mm arbor is a common size, so replacement blades are easy to find. The parallel guide helps with straight cuts along an edge. The compatibility with guide rail systems from Bosch, Mafell, Festool and Makita is a major advantage. You can run the saw on a rail for perfectly straight cuts across the full length of a sheet.

One thing to bear in mind: battery and charger are not included. You'll need an existing Bosch Professional 18V battery or buy one separately. The saw works with the Professional 18V System and is compatible with AMPShare, the battery platform shared by multiple brands. The battery capacity of 4000 mAh (if you use a battery of that size) is a guideline – actual run time depends on the load. Heavy work in hardwood will drain the battery faster than light cutting in plywood.

The noise level of 91 dB is normal for a circular saw. Hearing protection is recommended, especially for prolonged use. The rapid motor brake is one of the few safety features – there's no laser guide or other aids. That's no loss if you're used to following a cut line, but for precision work a laser can be handy. The saw is not suitable for metal or stone – you'll need different blades and machines for that.

The GKS 18V-57 G weighs 5.70 kg without battery. With a 4000 mAh battery fitted, you're looking at around 6.5 kg. That's not lightweight, but the soft start and balanced design make it manageable. The box contents are: the saw itself, one Standard for Wood 165 mm saw blade, an extraction adapter, a hex key and a parallel guide. That's all you need to get started – apart from a battery and charger.

The 20 mm arbor is a standard size. Saw blades with this arbor are widely available, from coarse blades for fast cutting to fine blades for clean finishing. The included blade is an all-rounder for wood. For specific work – such as laminate or plastic – you can fit a different blade. The spindle lock makes swapping quick: tighten the spindle with the hex key and the blade is secure.