PRO Heavy Duty Zinc Alloy Knife

That matters more than convenience. A blunt blade is the main cause of knife injuries, because a dull edge does not cut — it skids off the material and goes wherever the force was pointing, which is usually towards your other hand. People persevere with blunt blades because changing them is a nuisance. A snap-off blade removes the excuse.

This is the Pro heavy duty version and the housing is what distinguishes it. Zinc alloy rather than plastic gives a rigid, heavy body that does not flex when you press hard into a cut, and flex is what makes a knife wander off a straightedge. The metal flute — the channel the blade slides in — is the part that decides whether a knife is any good. A blade held in a sloppy or worn flute rocks under load, and a rocking blade snaps rather than cuts. A metal flute holds the blade rigid and stays that way after months of blades sliding through it, where plastic wears.

It comes with one blade fitted and takes Harden 570343 SK5 blades, which are worth buying a box of at the outset.

The buyers are shopfitters and installers, carpet and flooring fitters, signage and display makers, packing and dispatch departments, insulation and drylining contractors, and hardware dealers, who sell knives and blades continuously.

Three habits, all of them safety habits. Extend only one or two segments of blade — a long extended blade flexes and snaps under load, and a breaking blade under pressure sends a piece somewhere. Cut away from your body and never towards your supporting hand. And snap the blade off with pliers, holding the segment in a cloth or inside the snapper on the cap, not with your fingers; a snapped segment is razor sharp on every edge and it flies.

Retract the blade every single time you put the knife down. The most common knife injury is not made during a cut — it is reaching into a bag or a pocket where an open knife is lying. Message us on WhatsApp for a price, or with a box of blades.