The case and primer were made at the Osaka arsenal, the case in July 1942 and the primer in May 1942.
Reading clockwise from bottom right of the casing, the kanji symbol sho 昭 denotes the Showa era - the reign of the Emperor Hirohito.
Then the kanji for 17 is written here vertically as 十 (10) above 七 (7), giving the year Showa 17. With 1925 as the datum, effectively year zero, the western year is 1925 + 17 = 1942.
The month is usually denoted by an Arabic numeral - in this case 7 for July.
The crossed cannons symbol is the monogram for Osaka arsenal.
The partial segmented circle symbol might be an inspection mark.
Then there is the kanji symbol saka 阪, denoting an Osaka arsenal supervisor's inspection (the kanji 大阪 being Osaka).
The western letter F has been the subject of previous discussion - could be case hardness, or filling, or other inspection. One of the Japanese ordnance experts will have an answer.
As for the primer, the year kanji are written horizontally rather than vertically. There is also a small inspection mark which I can't make out.
For any other cases or fuzes and knowing the Showa kanji, if you look up Japanese numbers any date can be logically worked out.
Tom.