On Sun, 24 Nov 2019 20:09:37 +0000, ss wrote:

On 24/11/2019 17:08, Caecilius wrote:
Many of the mortice latches on my internal doors are not as smooth as
I'd like.

Before buying I would strip one down and try and identify the issue, in
many cases using a small file to smooth any sticking areas can resolve
the problem.

They are not easy to strip down without damage though, as they're
assembled with spot-welds or rivets. Even if I could get them apart
without damage, I'd find it hard to put them back together again.