Which cylinder size do I need?

A cylinder that is too short will not fit. One that sticks out too far is easier to grip. Measuring takes two minutes and all you need is a tape measure.

What to measure

You measure two distances, both from the centre of the fixing screw. That screw sits in the narrow edge of the door, level with the lock.

• A: to the outer face of the fitting on the street side.
• B: to the outer face of the fitting on the inside.

The fitting is the plate or rose around the keyhole. Measure to its outer face, not to the wood of the door.

Which size to choose

For each side, choose the next size up from your measurement. The Lunvik Core comes in 31 to 71 mm per side, in steps of 5 mm. If you measure 44 mm, choose 46.

Always round up, even if your measurement is only just above a size. If you measure 42 mm, choose 46 and not 41: a cylinder that sits inside the fitting will jam.

Anti-pull protection

Security fittings with anti-pull protection are thicker than ordinary fittings. If one is already on your door, measure to its outer face. If it is still to be fitted, allow for a larger outside size; the size guide adds it for you. Make sure the outside knob stays clear: a fitting that covers the cylinder completely does not suit a cylinder with a knob.

Two sides, two sizes

Outside and inside often differ, because the lock is not in the middle of the door or the outside fitting is thicker. That is why you set each side of the Lunvik Core separately.

The size guide does the maths for you and sets the configurator to the right size.