Surelock McGill fire exit crash bars are high security door furniture used by many High Street banks. They offer long life, very good security and are very well made.

We were called to replace the lock on the external side of this fire door as keys had been lost.

We removed it from the door and found that the cylinder used, while ordinary at first glance was slightly different. When we had removed the actual key cylinder from the housing it was in we found that the tail piece screwed to the back of the lock was different to that on usual cylinders. The orientation of the screw holes on the back of it were at a 45 degree angleĀ  (one in the top corner and the other in the bottom corner). Looking through the stock on the van we couldn’t find an identical match – even though we had some Union branded locks that looked identical, the screws were in a different place, so just re-pinned their existing cylinder to provide them with a new set of keys (old keys will no longer work this lock).

The external handle / lock unit on the door is for granting access in through the door (with the right key). It’s called a “Leo unit” (this is an abbreviation for: Lock with External Override) on this locking system and it isn’t always used. Many places have the identical crash bar system in the inside of the door, but not many tha external handle to let yourself back in that way.

Below are many images of inside the Leo unit as we don’t strip these down regularly and I’m sure that there are lots of people who have never done this and might like to know what’s inside.

Surelock McGill fire exit Leo unit on steel fire door
Surelock McGill Leo unit on steel fire door
Surelock McGill dismantled on steel fire door
Surelock McGill - Union cylinder from inside the Leo unit
Inside the back of the Surelock McGill Leo unit
Inside the back of the Surelock McGill Leo unit - Tail is now back on the Union cylinder lock
Inside the back of the Surelock McGill Leo unit - with the back plate and the square drive for the spindle
Union cylinder plug removed for re-pinning
Inside the back of the Surelock McGill Leo unit - Sliding locking plate is now re-assembled
Inside the back of the Surelock McGill Leo unit
Surelock McGill Leo unit removed from steel fire door