SMT Threaded Standoffs & Inserts Keystone Electronics SMT Threaded Standoffs & Inserts are available in a 2-56, 6-32, 4-40, or M3 thread size with a height of 0.3mm, 2mm, 3mm, 4mm, 6mm, 6.35mm, 8mm, or 10mm. These components are made of steel with a tin finish / plating and available in tape and reel packaging. Keystone Electronics SMT Threaded Standoffs & Inserts are RoHS compliant and ISO 9001:2015 certified.