Sash lock dimensions

[MadAlicesDad]

I need to uprate a sash lock to meet insurance requirements and seem to have options of (nominally) 64mm or 76mm.
Is this the dimension from the face of the lock (effectively the distance the lock goes into the door) and thus determines the position of the handles/keyholes?
Mike

 

[xerxes]

These are, probably, the dimensions of the cases; the backset, that is the distance between the edge of the door to the centre of the handle spindle, will be a lower figure, for example it could be 57mm backset for a 76mm case. But you will have to check the specification.

 

[MadAlicesDad]

Thanks for the quick reply!
Cheers,
Mike

 

[JohnD]

easiest thing is to take out the old lock and measure it

with luck the makers of the old lock make a new one of the same size, although if the old one was a 3-lever it will probably be thinner than the replacement 5-lever.

Different makers have slightly different dimensions.

BTW the top value "Best Buy" in the 2007 "Which" lock test was the £27 new Union 2134E* (British Standard BS7950) beating many much more expensive locks. It scored the same as the £165 Ingersoll and more than the £107 Bramah or the £142 Banham as well as the £42 Chubb. I was quite surprised.

*This is the deadlock but they make a similar Sashlock, type 2234E

 

[MadAlicesDad]

with luck the makers of the old lock make a new one of the same size,

I doubt it, the existing lock is over 50 years old - had mm been invented then?

I have taken it out and measured it - I need to relate this to modern locks. I'll pop down Q&Q tomorrow and measure up, then come home and order one at an acceptable price on t'internet.
Thanks for the suggestions ref options and VFM.
Mike

 

[JohnD]

the existing lock is over 50 years old - had mm been invented then?

yes, but lots of British locks were two and a half inches, two and five-eighths, or three inches, or three and a quarter.

This explains the strange widths when you might have expected them to be 50mm or 75mm if they were designed in metric

Chubb locks in particular are in a very strange assortment of sizes and the idea of interchangeability does not seem to have occurred to them.

 

[MadAlicesDad]

VMT John, perhaps I will find an easy swap for the existing lock. My original question was to ascertain which dimension the 64/76mm referred to so I could compare it to what I had.
Cheers,
Mike

 

[JohnD]

they usually mean the case width.

Those sound like two and a half and three inch (ish) cases

If you already have spindle holes and keyhole, measure that backet too

 

[rickles]

Mike,
johnD is right about the 2134E union deadlock and the sashlock too. they are first rate. i purchased one a couple of weeks back for my nan whose lock hadn't been updated in many a year. got a good deal at Handles4Doors where they start prices from £24.40. and when i bought it delivery was free for july - not sure if they've carried this on for august but worth a look...
cheers
rickles

***Removed***

 

[MadAlicesDad]

I actually found a simpler (and cheaper) solution. I read the insurance requirements again and an alternative to the sash lock is two key operated bolts fitted top and bottom. We already have those fitted but one of them never worked. Turns out the key was damaged. Changed they key, lock works fine.
It seems odd that a BS 5 lever lock can be equivalent to two key operated bolts with no specification, but insurance requirements are met!
Thanks for the suggestions.
Mike

 

[JohnD]

that must be a on a back door (unless you live up North where they never go through their Front doors)

The Final Exit Door is the only one that you can't bolt from the inside before you go out, so if you can only afford one good lock, that's where it must go

Preferably have a good lock supported by mortice bolts on your other doors

You are supposed to take the keys out after locking them.