Paragon Machine Works builds all sorts of assemblies that custom frame builders use: bottom bracket shells, brake mounts, cable stops, dropouts and adjustable dropouts, tubing, stem parts, and tools for frame builders.
Paragon Machine was founded in 1983 in Marin County, California, by owner Mark Norstad. It has since grown into a thriving machine shop now based across the bay in Richmond, Calif. They are now the largest US manufacturer of frame components, and they have them in stock for immediate delivery.
Not a frame builder yourself? Paragon offers other items like high-quality axles and skewers that you can purchase directly from their website, as well as another indispensable item valued by both frame builders and armchair cyclists alike: bottle openers.