As I had pointed earlier, going back to the Endura or the Delica (no choil, lockback, steel spacer) is like going vintage in a beautiful way. Those are the roots of  modern “tactical” folders: “one hand opening and closing” and “Clip-it”.  The Endura I have bought from the Knifecenter is just flawless: zero blade play. It’s a great perfectionist work from Seki knifemakers but lockwise it was not the case with my Delica: it has a noticed vertical play while cutting hard things.

The results on wood cutting were top-of-the-notch despite that annoying recoil of the lock on each hard cut.

I have been looking on the internet and the forums and someone mention to tight the screws. Why not ?

I have found those torx screws were not tied and I could easily adjust them in an half of a turn clockwise.

The lock screw was also easy to turn and now I don’t have that annoying vertical play anymore. Hurrah !!
Here is my solution: the handle screws need half a turn. I have done it on my Stretch and it is also now perfect.

Before when only bolts were used in knife construction it was not possible… But with the Delica 4 all screws construction it’s easy to adjust them.
The action is a little more stiff but no more recoil while cutting hard things like wood or plastic.