Handing: The One-Letter Answer That Holds Up Orders

Handing describes which edge of the door the hinges are on and which way the leaf swings. It matters because a lever has to fall the right way, a latch bolt has a bevel that must face the frame, and a lock case machined for one hand will not close on the other. It is one letter, and it is the field most often left blank on an enquiry.

There are two conventions and they do not agree. The European method stands the observer on the side the door opens TOWARDS — the pull side — and calls it left-handed if the hinges are on the left. The American method (ANSI/BHMA A156.115) stands the observer OUTSIDE, on the side you would use a key from, and adds "reverse" for doors that swing away. The same physical door is DIN-left under one and right-hand-reverse under the other.

This is why "left-handed" written on its own is not an answer. It is an answer plus an assumption about which convention the reader uses, and the reader is on the other side of the world. The reliable way to say it is to describe the door: hinges on the left as you look at it from the corridor, opens away from you. Twenty words that cannot be misread beat one letter that can.

A useful test that needs no convention at all: stand where the key goes. If the hinge knuckles are on your left, it is left-handed in the American sense; if the door swings towards you from there, it is "reverse". Say which side you stood on and the sentence survives translation.

Some hardware does not care. A tubular latch with a symmetrical bolt, most euro-profile cylinders, hinges themselves, and any lever on a sprung rose are non-handed — universal, marked U — and the field can honestly say so. Reversible latches are a middle case: the bolt can be turned on site, which is a real convenience and also a real opportunity for it to be turned wrong and never checked.

What is genuinely handed, and where the cost lands: mortise cases with an asymmetric follower, rebated pairs, and anything with a deadlocking latch whose auxiliary bolt has to meet the keep. On those, a wrong hand is not adjustable with a file — it is a different part number, and on a container quantity it is a different shipment.

The practical rule for a schedule: give every opening a hand or the word universal, and never leave the column empty. An empty column reads as "not decided yet" to the person filling the order and as "universal" to the person in a hurry, and only one of those is safe.

Where a model is handed, our specification tables state it as a row rather than burying it in the description, and the guided selector asks for it before it offers a model number — because the answer changes which models can be offered at all, not just which variant of one.