Sigma Tool & Machine manufactures t-nuts, rivet nuts, and insertion equipment and furniture clips for the upholstered furniture industry.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 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.hand held tnut tool 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-NutsSigma 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.
