Selling a perfectly good lock with four keys (£15 to buy the keys alone)
What size do you need?
It’s vital that you order the correct size cylinder for your door. To determine which size cylinder you require you must first remove the cylinder.
Removing existing cylinder
Put your key in the lock and open the door.
Remove the screw which is beneath the latch.
Turn the key while apply slight pressure to the opposite end of the cylinder. As you do so the cam will line up with the rest of the lock and you will be able to slide the cylinder out towards yourself. The key usually needs to be turned approximately 25º clockwise or anti-clockwise.
You can now measure the original cylinder.
Measuring the existing cylinder
On the side of the cylinder, under the cam, you will see a Fixing Hole. The size you require is determined by the distance from each edge of the cylinder to the centre of the fixing hole. See attached photo..
Measure from the end of the cylinder to the center of the Fixing Hole, to give the first measurement (a)
Measure from the center of the Fixing Hole to the other end of the cylinder, to give the second measurement (b)