A common view is that a door chain is an old-fashioned fitting, something from a grandparent’s flat that modern smart locks have made pointless. That view misses what a chain is for. A smart lock decides whether the door opens. A brass door chain decides how far it opens. That second question is the one that matters when a stranger is standing on the landing, a delivery needs signing for, or someone claims to be from the electricity board. A good chain, fitted properly, lets you open the door a hand’s width, see the person clearly, take a parcel or hand over a document, and close it again without ever giving up control of the doorway.

Why a brass door chain still makes sense

The chain’s value lies in the gap it creates. With the chain engaged, the door can only open a short distance before the chain pulls tight. That is enough to talk face to face and pass small items through, not enough for anyone to push their way inside. For elderly people living alone, for families with children who answer the bell, and for anyone who works from home and receives many deliveries, that controlled gap is worth having.

Brass is a natural material for this job. It resists corrosion, so a chain on a main door that faces an open corridor or a monsoon-soaked verandah keeps working smoothly and does not rust into a stiff, ugly lump. Brass also has the weight and solidity people expect from main door hardware, and it pairs well with brass mortise handles and door knockers. Over the years it takes on a softer, lived-in tone rather than flaking.

What to check before you buy

Look first at the chain itself. The links should be solid, evenly formed and closed properly, without gaps where they join. A chain is only as strong as its weakest link, and a link that can be prised open with a screwdriver defeats the purpose. Lift it. A chain that feels flimsy in the hand will feel flimsy in a doorway too.

Next, check the two plates, the one that fixes to the door frame and the slide or track that fixes to the door. Both should be thick enough not to bend, with countersunk holes for screws that sit flush. Ask how long the supplied screws are. Short screws into a soft frame are the most common reason chains fail. The chain plate on the frame should ideally take longer screws that bite well into solid timber behind the architrave.

Finally, check how the chain slides. It should run smoothly along its track and drop into the open position without catching, so that you can engage it quickly in the moment you need it. A chain you avoid using because it is fiddly is no use at all.

Installation height and position

There is no single correct height, but there is a sensible principle. Fit the chain where the adults of the house can reach it easily without stretching, usually a little above the handle and below eye level. That keeps it near the door viewer, so you can look through the viewer, then engage the chain, then open the door, all from the same standing position.

If the house has elderly family members, place the chain where they can operate it without bending or reaching overhead. If small children answer the door, some families place the chain slightly higher so the children cannot release it themselves. Make that choice deliberately.

Fix the slide on the door and the keeper on the frame on the same side as the lock, so the chain spans the opening edge of the door. Screw the frame plate into solid timber, not just a thin moulding. On steel or aluminium frames, use fixings meant for metal. Test it by opening the door against the chain several times, pulling firmly, to make sure nothing shifts.