BB mortise lock with silent latch bolt

Determine dimensions correctly:

Backset (in mm): Is the distance from the centre of the lever handle or lock cylinder to the front edge of the forend.

Distance dimension: Is measured from the centre of the lever hub or turning knob to the centre of the cylinder recess (keyhole). This measure is standardized in Germany with the following dimensions:

• 72 mm for interior apartment doors
• 78 mm WC - doors
• 92 mm front doors / apartment doors outside

Square spindel:

• square spindel 8 mm for room doors
• square spindel 9 mm for fire protection doors
• square spindel 10 mm for external doors

Forend width and length: The forend is the front face of the mortise lock which is visible after installation in the door. The design of forend can be rounded or square.

Door alignment:

The DIN direction of the door alignment is also important for the selection of the mortise lock. A distinction is made here between DIN right and DIN left. If the door hinges are on the left-hand side when the observer looks at the closed door, this is a door with a DIN left alignment, if the door hinges are on the right side, this is a DIN right door alignment.

Rebated door:

The most used door is the rebated door. In it, the rebate is a small step at the edge of the door leaf. As a result, the door leaf rests on the frame. A seal on the frame (door frame) provides the necessary sealing and soundproofing.

Non-rebated doors:

Doors without a rebate are called non-rebated doors. Architects often require a harmonious and flush finish between the door leaf and frame. This is achieved by non-rebated door leaves. Due to the flushness of the frame and door leaf, it is an absolute eye-catcher in the room.