Sourcing small parts
When McMaster-Carr doesn’t carry the tiny parts you’re looking for, where can you go?
There used to be a company called Small Parts, and their catalog was great because everything in it was small. That simple selection criteria saved a lot of search time. They’ve been folded into Amazon Supply, whose large catalog and poor navigation tools make it difficult to find parts. They’re there, and the web site has some decent features. But the overall experience is frustrating and there are better options.
MiniTap and Fasteners supplies the small size (down to #00-90 and M.5) products that aren’t stocked at McMaster.
Component Supply Company has screw sizes down to #0000-160. They also carry a lot of small tubing supplies, including barbed connectors and blunt needles.
Some other options
Micro Fasteners
Albany County Fasteners
Microplastics for an array of plastic fasteners and other part.
According to conversations I had a with them a few years ago, Component Supply Company is actually run by former employees and managers of SmallParts, who took over some of the facilities and product lines that were not included in the Amazon acquisition.
For example, the fantastic custom cut-to-length tubing service formerly offered by SmallParts is still offered by CSC: http://www.componentsupplycompany.com/Capabilities.html