Adjustable T-shaped Square Ruler (24"/600mm)

Used as a plain T-square, the head sits against the edge of a sheet and the 600mm blade projects across it, giving a line square to that edge — the basic operation for cutting plasterboard, plywood, MDF, panelling and sheet metal, and one that a tape and a straightedge do slowly and less accurately.

The adjustment adds fixed angle settings at 90, 75, 60, 45 and 30 degrees. Those are the angles that come up: 45 for mitres and diagonal bracing, 30 and 60 for roof and triangulated work, 75 for splayed and angled cuts. Being detented at those specific angles rather than infinitely variable is an advantage for repeated work — you can set it, cut fifty boards, and know every one is at the same angle, which a free-moving bevel cannot guarantee.

Six hundred millimetres of blade covers the width of standard plasterboard and reaches usefully across sheet material, which is what makes it a drywall and dry lining tool as much as a joinery one.

The material is aluminium alloy, which is the right choice here for a reason beyond weight: a T-square is carried around a site all day and pressed against sheet edges constantly, and aluminium is light enough to use one-handed while stiff enough that the blade does not deflect. It also does not rust.

The buyers are drywall and partition contractors, ceiling and dry lining installers, carpenters and shopfitters, sheet metal workers, sign and display makers, kitchen and wardrobe installers, and hardware dealers supplying interiors trades.

Two things. Hold the head firmly against the sheet edge throughout the cut or the mark — the accuracy comes entirely from that contact, and letting the head lift even slightly at the end of a stroke puts a curve into what should be a straight line. And check the 90 degree setting occasionally with the flip test: mark a line, turn the square over on the same edge at the same point, mark again, and the two should coincide. An adjustable head has more places to go out of true than a fixed one, so the check is worth doing after any drop. Message us on WhatsApp for a price.