Walter J. (Walter John) Kleinlein

Walter J. Kleinlein, also listed as Walter John Kleinlein, was an American technical writer on horology born in 1876. Public records and library listings identify him as the author of specialized works on watch repair and adjustment, including Rules and Practice for Adjusting Watches.

His books were written for people working closely with mechanical watches, focusing on the careful methods needed to regulate and improve their performance. Surviving editions and catalog records also connect him with Practical Balance and Hair-spring Work and describe his writing as practical, trade-centered instruction rather than general-interest commentary.

Reliable biographical detail appears to be limited online, but genealogical records indicate he died in 1951. No suitable verified portrait image was found from the sources reviewed, so a profile image is not included.