kwb 109178 8-Piece Bi-Metal Hole Saw Set, 67–127 mm, HSS Centre Drill

For fitting light switches or sockets during a home renovation, the kwb 109178 hole saw set gives you a choice of cutting sizes in one organised kit. It includes five hole saws for diameters of 67 mm, 76 mm, 89 mm, 102 mm and 127 mm, plus an HSS centre drill. The sturdy plastic case keeps the pieces together between jobs. Need different openings across the same project? The range of sizes makes it practical to select the right saw as the work progresses.

Why it makes sense

A set of several diameters offers more flexibility than buying a single hole saw for one opening. Choose from the included sizes to suit different fittings and household tasks, with the hexagonal shank designed for use with standard machines. The saws have progressive teeth that help eject chips and support faster cutting, making the set useful for planned renovation work as well as general DIY tasks.

The stated applications include soft wood, plywood, plasterboard and fibreboard. That makes the set relevant for jobs such as preparing openings in boards for switches, sockets and similar fittings. For example, when renovating a room, you can use the appropriate diameter for each opening rather than relying on one size throughout. The bi-metal blades and HSS centre drill form part of a practical kit for this type of hole-cutting work.

Quick overview

The eight-piece set comprises five hole saws, a mandrel with HSS centre drill, a hexagonal wrench and a mounting plate. The five cutting diameters are 67 mm, 76 mm, 89 mm, 102 mm and 127 mm. Progressive teeth are designed to improve chip ejection and cutting speed, while the hexagonal shank provides a connection for standard machines. The supplied case helps keep the components organised and ready to take to the next job.

The set is intended for use on soft wood, plywood, plasterboard and fibreboard. Match the selected saw to the opening required and the material being worked on. It is a useful alternative to assembling separate hole saws individually when a project calls for several sizes and their associated fittings.

Practical tips

Before starting, choose the diameter that corresponds to the opening needed and make sure the workpiece is one of the stated materials. Assemble the selected hole saw with the mandrel and HSS centre drill, then secure the hexagonal shank in a compatible standard machine. The included hexagonal wrench and mounting plate support assembly, while the case provides a place to store the set together after use. Keeping the components in their case also makes it easier to find the size needed for the next opening.

Final verdict

The kwb 109178 is suited to DIY users and tradespeople who need several hole sizes for light fitting, socket and renovation work in wood-based boards, plasterboard or fibreboard. Its five diameters, HSS centre drill, assembly accessories and sturdy storage case bring the key pieces together in one set, giving you a practical choice of sizes for varied hole-cutting tasks.