These are the retailers I use for almost all of my projects. The companies listed here are reliable and have a good stock coverage that offers almost everything you need for a given project. Between all of them I am basically covered, save for the odd item now and then. Be sure to check these out -- whether you are in a project now or thinking about starting, it's always good to know what is available in the market. You also might get some sweet ideas by browsing their catalogs!



Materials Suppliers
Robotics Parts/Hardware
OnlineMetals.com
The Web's superstore for small quantity metal orders welcomes you to explore exceptional metals sales and service from metal buyer's guides, to metal project ideas.
ServoCity
One of my favorite retailers -- lots of actuators and everything you need to support them -- gears, bearings, chains, pulleys, even the electronics to drive them!

US Plastics
This is a great resouce for sheet plastic, rods, buckets, dvd cases -- anything plastic you need, they probably have it at a great price. An honorable company.
Lynxmotion
Another favorite, mainly for their servo controller boards - best deal for features/price/reliability I've found. They also have some really neat kits and standardized components.

RTL Fasteners
Need to buy bulk hardware or trying to find a specialty item? Try RTL-- they have good prices, fast shipping, and a great selection.
Jameco
Your one-stop-shop for electronics such as microcontrollers, solenoids, PCBs, and integrated circuits. Check out their massive online catalog with RoHS compliant products.

BoltDepot.com
Fast shipping, cheap rates, and no minimum order. Plus, for orders over $50 you get free shipping -- on hardware!! Good selection of standard hardware.
E-Clec-Tech
Carries a wide variety of stuffs ranging from anatomical models to high power gearhead motors -- a lot of things you need for a project, and some harder-to find parts as well.

MSCDirect.com
MSC has a massive catalog -- they literally call it the "Big Book." This monster has almost everything you need to stock a tool shop or start a project.
RobotStore.com
This is a neat little store that Jameco bought a few years ago that has some really great educational kits as well as a solid offering of mechancial/electrical components.

McMaster Carr
One of the widest selections of components with a GREAT website to back it up -- wheels, screws, tooling blocks, bolts -- anything for your shop or project, be sure to check here first.
DigiKey
The perfect complement to any electronics project, DigiKey carries a huge selection of IC components.

Carr-Lane
A company not spoken of enough outside of industry, Carr-Lane has some of the best tool holding and machining components around. They also carry a wide selection of handles, lead screws, and other neat parts.