About Sigma


Sigma Tool & Machine was founded in 1954 as a tool and die shop in Toronto Canada. Shortly afterwards, the company began making various metal stamped components for local bedding manufacturers, including T-Nuts and clips. 

In 1964 Sigma introduced and patented the first 4 prong T-Nut with the now familiar 8-sided base. Unlike the standard round base T-Nuts, the new Sigma T-Nuts could be fed efficiently and reliably by machine. The 8-sided base has become the standard configuration for T-Nuts inserted by machine.  


Sigma Tool & Machine is one of the world's largest manufacturers of T-Nuts for the upholstered furniture industry.  Sigma offers a full line of machinery and equipment for inserting T-Nuts into wood or plastic components.   

Sigma has supplied over 1800 T-Nut Machines to manufacturers throughout the world, including North and South America, Europe, South Africa, New Zealand, Australia, and Japan. 


Sigma also manufactures various upholstery spring wire clips. Sigma offers fully automatic, semi automatic and manual clip machines for the AKH-1-2 clips. Hand tools are also available for all CLP clips.