Pickett and Eckel
manufacturer of slide rules, American
Lewis & Tylor Limited
active 1952, manufacturer of slide rules, Cardiff, Wales
Pickett
active 1960s, manufacturer of slide rules, Chicago, United States
Unique Slide Rule Company Limited
active 1930s-1990s, manufacturer of slide rules, Newhaven, England
Lawrence Engineering Service
active 1946, manufacturer of slide rules, Peru, Indiana, United States
A W Faber-Castell
active 1900-current (2007), maker of drawing instruments, slide rules & art supplies, Germany