MIWA WEST916.RA, Lost key, Unlocking the entrance door

"Lost key, Unlocking the entrance door"

The information was about a thumbturn with buttons and a thumbturn cover, but the reason was that the client was Vietnamese and could not explain it in Japanese.

When I checked on-site, it was a MIWA RA type, and when I looked at the photo, it was a standard type. However, things got difficult from here. Thumbturn slides. Even in RA, it is a square pyramid type and does not turn all the way. After about 5 shots, I finally unlocked it.

I checked it after unlocking it, but I didn't feel any hardness in the thumbturn operation. This is the type of lock I've worked on many times before, but I couldn't figure out why I couldn't unlock it smoothly this time. Anyway, the tip of the tool requires maintenance.