Q: Choosing ironmongery for four final fire exit doors and frames which will experience heavy traffic, and need to be secure (would prefer not to have a panic bar), can you recommend a handle arrangement, perhaps with a thumblock on the inside, that would be suitable for these circumstances?

A: For the arrangement you describe we would suggest using escape sashlocks – these have euro cylinder thumb turn locks (i.e. you can have any kind of high security, master keyed, anti pick, anti bump etc euro profile cylinder) but use a split spindle so from the inside the handle will ALWAYS over-ride the lock and open.  The sets we supply include standard differ cylinders, which you can see on the website clicking the bold link, talk to us about higher security cylinders or masterkeying.