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.
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 1000 T-nut Machines to manufacturers throughout the world, including North and South America, Europe, South Africa, New Zealand, Australia, and Japan.In addition to standalone t-nut machines, Sigma has T-nut Drive heads that can be mounted onto routers, double end-tenoners, or other specialized equipment to integrate t-nut insertion into an automated production process.
Sigma also offers a number of fully automatic CNC or robotic T-Nut Punching Systems that punch the t-nuts into the material, eliminating the need to pre-drill holes.
In 1999 Sigma introduced the first Hand Held T-nut Tool, a lightweight and portable tool similar to a pneumatic stapler that drives Collated T-nuts. The hand held t-nut tool is also available in a rivet t-nut configuration to drive Sigma 2 prong Rivet T-Nuts
Sigma also manufactures various upholstery spring wire clips, including Nosag style EKS clips, Hartco type CL and AK clips, and the Sigma ELC or Euro Life Clip.