Latch size

76mm or 63mm depends on whether you can get a 76mm latch in, style of door and where it places the handle will determine which one you use, I tend to use 76mm on fire doors which sometimes have a 1 inch door stop, allows the handles to have a bit of space from the stop...if all that makes sense....

B J

 

I would say that 63mm is probably more common, the chippies doing it daily will be better placed to say on that, I would want the handle to be sitting between the stop and the groove on the door so it looks neat when closed...is your fire door flat panel?

 

What sort of handles have you ordered?

 

they will be ok. was worried you might be getting knobs.

 

If the stile is around a 100mm (4") then use the 63mm (2.5") one, when set in the door the handle should then be almost as near as dam it in the middle of the stile.

 

With those handles on door frames with standard door stop whether you go for 2.5" or 3" won't make much difference, however if you want the centre of handle as close to the centre of the stile as possible as Phil says then look at the stile width and use that to decide, generally from my experience with those style doors, the smaller sizes up to 1'9" tend to be 100mm stiles then onwards are 120mm, so a 2.5" will be close to centre on the small sizes and 3" would be closest on the rest.