Russian Shashka

[ariel]

It is not "Yafe": "Shaf & sons". What you read as "E" at the end of his name is in fact "Ъ", a silent letter put after a final consonant: standard pre-revolutionary Russian orthography. This was the biggest Russian company supplying blades for the military.
Wilhelm Shaf ( or Shaaf) moved from Solingen to Zlatoust in 1815 together with his 3 sons, promising to teach Russian workers his techniques. In 1824 he left Zlatoust and established his private company in St. Petersburg.

The above style of markings was active after 1880. The blade bears the monogram of Nicolas II, the last Tsar, who ascended to the throne in November 1884. In 1914 the name of St. Petersburg was abolished to Petrograd in a wave of anti-German sentiment.
All this is in accord with the "1881 Pattern" of this military Shashka.
Shafs left Russia after the 1917 revolution. So, the date is between 1885 - 1914.