Universal or Handed 2026: Which Hardware Is Reversible, Which Is Not, and the Four Products That Catch Projects Out

A catalogue says "universal" and a buyer stops worrying about handing. That is the intended effect and it is right about a third of the time.

The word covers three genuinely different situations, and the difference decides whether a wrong hand is a five-minute fix, a two-minute fix, or a new order.

The three meanings of universal

Only the first is genuinely universal. The second is the one most catalogues mean when they say it, and the distinction matters because field-reversible still requires somebody to do the reversing — and on a job where forty doors arrive the day before handover, "a few minutes each" is a day nobody planned.

What is genuinely non-handed

Most butt hinges, on a normal swing door. A hinge is symmetrical about its pin; the hand is decided by which side of the opening you fix it to.

Most rose-mounted lever furniture, where the lever is a straight or gently curved form with no asymmetric detail. A rose is round and a plain lever reverses by turning it over.

Pull handles, push plates, kick plates, door stops and most flush bolts.

Cylinders. A euro or oval cylinder has no hand; what it has is a length and a split, which our euro cylinder page covers and which people sometimes confuse with handing because getting either wrong produces the same symptom — a part that does not work on this door.

What is field-reversible, and what reversing actually does

Most cylindrical and tubular latches reverse by turning the latch bolt through 180 degrees, so the angled face meets the strike on the other side. On many models this is a push-and-turn action with no tools.

Most mortise lock cases reverse the same way, sometimes after removing a screw or a retaining plate. What is reversing is the **latch bolt only** — the deadbolt, if there is one, is symmetrical and does not care.

That is the whole mechanism in one sentence: **reversing a lock means turning the latch bolt round so its ramp faces the closing direction.** Everything else in the case is usually symmetrical.

Two consequences follow. Reversing is quick when the model allows it and impossible when it does not — there is no partial version. And a lock that has been reversed on site is a lock somebody opened, so on a fire door that is a change to the assembly unless the reversal is within what the manufacturer's instructions permit.

The four products that catch projects out

These are the ones where people assume universal and are wrong.

**Exit device outside trim.** The device is usually non-handed; the trim frequently is not. A lever trim has a lever that must point the right way and a tailpiece that must engage from the right side. Our exit device trim page treats the trim as the whole specification for exactly this kind of reason.

**Door closers with parallel arm mounting.** The body may be non-handed; the parallel arm assembly generally is not. A closer ordered as "non-handed" and mounted parallel arm may need an arm set that was not in the box, which our closer mounting page covers.

**Levers with a shaped or asymmetric form.** A lever with a thumb detail, a sculpted underside or a directional taper does not reverse by turning it over — it becomes upside down. This is the one that survives a photograph and fails on the door.

**Lock cases with a dead-latching plunger or an offset follower.** Some cases are dimensionally symmetrical and functionally handed. This is the least visible of the four and the most likely to be discovered by an installer at the end of a corridor.

Why "reversible" and "reversed" are not the same word on a delivery note

A small but expensive distinction on large orders.

A reversible product **ships in one hand**. If a schedule says forty left-hand doors and the product is reversible, somebody still has to reverse forty locks — or the supplier does it before packing, which is a request that has to be made.

So on a large order, ask for the product to be **supplied reversed to the required hand**, not merely for a reversible product. It costs nothing at the factory, where a latch bolt is turned before the box is closed, and it costs a day on site if it is not.

And if the order is mixed, state the split — "24 LH, 16 RH" — because a supplier who is not told will ship all one way and be correct.

The two conventions, in one paragraph each

Enough to use, without repeating our handing page in full.

**The European convention** looks at the door from the side it opens towards you — the pull side — and names the hand by which side the hinges are on. Hinges on the left, left hand. It is the convention behind the DIN designations you will see on European product codes.

**The North American convention** stands on the outside of the door, and adds a second axis: whether the door swings away from you or towards you. That produces four terms rather than two — left hand, right hand, left hand reverse and right hand reverse — where the reverse pair covers doors that swing towards the person standing outside.

The trap is not that the conventions disagree. It is that **a door correctly described as left hand in one can be correctly described as right hand in the other**, and neither party has made a mistake. That is why the convention has to be named beside the hand, every time, and why "LH" alone on an international order is a coin toss.

How to check a door in ten seconds, whichever convention you are in

Stand at the door. Note three things and the hand falls out of them in either system.

**Which side the hinges are on**, as you look at it.

**Which way it swings** — towards you or away from you.

**Which side is the outside**, which on an external door is obvious and on an internal one is a decision somebody has to make and record.

Write those three down rather than a hand. Three plain observations survive translation between conventions, offices and languages; a two-letter abbreviation does not. If a schedule carries all three, anybody downstream can produce the correct hand in whichever system they work in — and, more usefully, can tell when the hand already written is wrong.

Where handing stops being reversible: the survey point

On a refurbishment the hand is not a choice, it is a measurement, and the measurement has to happen before the order rather than after.

Two things make this harder than it sounds. A building rarely has one hand — corridors alternate, and a floor that looks symmetrical usually is not. And doors get rehung: a leaf that was swapped end for end during a previous refit carries hardware in a hand that matches nothing else on that floor.

So survey the doors rather than the drawings, count both hands, and record the split per floor. Our interchangeability page covers measuring the lock itself; the hand is the one field you can capture from the corridor without touching anything, and it is the one most often taken from a drawing that stopped being true years ago.

The line to put on an order

Name the hand **and** the convention. "Left hand, European convention, viewed from the outside" is unambiguous. "LH" alone is not, because our handing page sets out how the European and North American conventions can describe the same door with different words.

Say which side is outside, on a door where that is not obvious — a plant room, an internal corridor between two spaces, a door between two rooms that both think they are inside.

State whether reversible is acceptable or whether supplied-to-hand is required, per the section above.

And on pairs, state it per leaf. A pair is two handed doors, and a schedule line that gives one hand for a pair has described half the opening.

What we publish, and the honest gap

Where a model is handed, the product page says so and the order code carries it. Where a model is reversible, the page says reversible rather than universal, because those are different promises and we would rather write the narrower one.

What our pages do not yet consistently state is **which hand a reversible product ships in by default**. That is the information behind the "reversible is not reversed" point above, and until the rows carry it the answer comes per order rather than from the catalogue.

As with the dimension gaps on our interchangeability page, that is a reconciliation job rather than something to fill in with a plausible default — a default hand written into a row and wrong on a hundred doors is a more expensive error than an absent row that gets queried. A survey that records three observations per door costs an afternoon and removes the single most common cause of a container arriving in the wrong hand.