Measure your old cylinder. We’ll show the size that fits.
Enter two measurements and the guide shows the right size and every cylinder we sell in that size: key both sides, thumbturn or half cylinder.
How to measure
It’s best to take the old cylinder out first. Undo the long fixing screw on the edge of the door, turn the key slightly and slide the cylinder out.
A (inside): measure from the middle of the fixing screw hole to the inside end.
B (outside): measure from the middle of the fixing screw hole to the outside end.
C (overall): measure the whole cylinder end to end. It should equal A + B. If it doesn’t, measure again.
Between two sizes?
A cylinder should stick out no more than 3mm past the handle. If your measurement falls between two sizes, choose the shorter one, as long as the cylinder won’t end up below the handle faceplate. The guide does this for you.
Key both sides cylinders fit either way round, so a 35/45 also fits a door that needs 45/35. For thumbturns, A is always the thumbturn side.
Not sure? Send us a photo or call 01209 200564.