Without the correct grade of hinges your doors may fail. Failure doesn’t mean that your door falls off its hinges; normally failure comes in the form of a door starting to stick or rub on the door frame. If it’s sticking along the edge of the door against the frame anywhere above the lock or latch, then the top hinge may have failed. Often it’s the pin that stretches. This is enough to throw the door out towards the frame. Another common symptom is where the lock no longer strikes the plate in the correct place, often leading to the key having to be forced to turn.
Another tell tell sign would be hinges that start to creek – that’s the hinge saying it can’t cope with all the weight. It’s the pin or flange on the knuckle of the hinge physically rubbing metal on metal.
On a regular basis I am asked to hang doors. Often the customer informs me that they have the doors and all the ‘furniture’ (hinges, handles, locks etc.). At the moment oak veneered doors seem to be in vogue. These doors weigh 25kg plus, then you have to consider that the latches and levers or handles add another 2-4kg. The customer can easily have parted with £150-£200 for each door set, but no consideration has been given to the hinges, and more often than not the cheapest are purchased as long as they are the right colour/finish. Those cheap hinges come with screws that I put straight in the bin as they sit proud of the hinge leaf, causing binding which in turn causes the screws to eventually pull out.
So without getting too pedantic about hinges, if time is spent ensuring that the correct grade hinge is used there will be no future problems.
The most important things to consider are the weight of the door and the application. By application I mean is it in a light domestic situation? An office? A potentially high traffic area? Interior or exterior? Fire rated? If that’s the case, is there a door closure? If there is, add 25% to the door mass.
Hinge grades are from 1 to 14, grade 1 being the lightest and grade 14 the heaviest.
The most common ones available are grades 7, 9, 11, 12, and 13. I personally would not use anything under a 5, even for light weight interior panelled doors.
Grade 7: Max door weight 40kg tested to 200,000 cycles (opening and closing a door)
Grade 9: Max door weight 60kg tested to 25,000 cycles
Grade 11: Max door weight 80kg tested to 200,000 cycles
Grade 12: Max door weight 100kg tested to 200,000 cycles
Grade 13: Max door weight 120 kg tested to 200,000 cycles
Also consider that hinges come with or without washers, or with bearings on some of the higher grades. For the door example above, that is a 25-30kg set (door and furniture), I would normally use a grade 7 washered hinge, and as it is an internal door a 75mm hinge x 3 per door would be employed.
If you really want to get into this subject there is a British Standard no.EN1965 that covers the subject comprehensively but I can think of better things to do!
Incidentally there is a patron Saint of hinges called Cardea who in Roman times was celebrated on the 1st of June.
