Japanese navy. Came with both wood and bone handles

 

Thank you Jareth. Very kind of you to share your knowledge.

 

正鋼 = sei hagane = Real / genuine steel.
@Edokko

 

Yep, it's read Seiko (not the watch !) and is an old style marking for carbon steel.

 

Many thanks. These knifes are interesting. I have several other variations.

 

If interested, here is another picket knife. This one with a wooden handle and various alternative markings.

 

Good morning,
Is mine WWII military issue, or is it a civilian folding knife? I used Google Translate to decipher the inscription. Wood scales handle, and It's very sharp. It's missing the bale. Thank you.