L. S. Starrett Co.
Athol and Newburyport Massachusetts, 1880-1994-

Tool Types: Calipers, Dividers, Household Tools, Levels, Machinist Tools, Rules, and Squares
Identifying Marks: L.S. STARRETT CO./ATHOL.MASS (sometimes on one line and/or without “CO”); The L.S.S.Co./Athol,Mass.

Remarks: The L. S. Starrett Company was founded in 1880 in Athol, Massachusetts and is still in operation.  They are a manufacturer of machinists' tools such as rules, squares, calipers, gauges and dividers.
Laroy (often incorrectly recorded “Leroy”) S. Starrett (April 25, 1836-1922) invented and produced the HASHER, a meat chopping machine patented May 23, 1865. A few years later, he went to work for the Athol Machine Co., which produced it in 1868. Circa 1875 he was prompted to quit due to mounting legal disagreements over patents including a particular combination machinists’ square he produced through the Richardson Machine Shop in 1877. In 1880, he won the lawsuit against Athol and formed his own company, buying out Charles P. Fay of Springfield, Massachusetts’s caliper and divider stock, machinery, and patents in 1887. His wild success allowed him to buy out his old employer and legal foil, Athol Machine Co., in 1905. Starrett held over 100 patents, including a particularly significant micrometer patented July 29, 1890. He also produced tools with pre-1900 patents of Frederick A. Adams, Frank G. Lilja, Morris F. Smith, Burnside E. Sawyer, John D. Sloan, Edward C. Clapp, Carl G. Osteman, J.H. Cook, Patrick Kennelly, and George Thompson (Nelson 1999).

Hasher

This is a 1864 Starrett "hasher", his first patented invention.  Photos by George O'Connor.

Much more information on L.S. Starrett is in our essay on Precision Toolmaking.

References:
Johnson, Laurence A. (December 1958). The hasher. The Chronicle.
Starrett. (July 1895). No. 13 catalogue and price list of fine mechanical tools, manufactured by L. S. Starrett Athol, Mass. U.S.A.
Starrett. The Starrett Book for Student Machinists.
Turner. The Starrett wheels that led to more wheels.
Links:
Link to the L. S. Starrett Company's website.
1898 photograph
A history of the L. S. Starrett Co. has been created by Rose Antique Tools.
Tools of the L. S. Starrett Co. in the Museum collection.