Model Rocket Resources: Model rocket links.
Liquid Fuel Rocket Motor: How to Design, Build, and Test Small Liquid-Fuel Rocket Engines, by Rocketlab. (Updated version.)
Rocket Mime: Rocket equations.
Nakka Rocketry: Rocket equations and theory.
Estes Rockets: Supplier of model rockets and rocket motors.
Apogee Rockets: Supplier of model and high-power rocket components, kits, motors, and instruction.
Giant Leap Rocketry: Supplier of model and high-power rocket components.
Missile Works: Supplier of high-power rocketry parts.
Performance Hobbies: Supplier of high-power rocket parts.
Wildman Rocketry: Supplier of rocket motors and rocket supplies.
Madcow Rocketry: Supplier of high-power rocket parts.
Aerotech Rocketry: Manufacturer of rocket motors.
Rattworks: Manufacturer and distributor of hybrid rocket engines.
Recovery and Parachutes
Perfect Flight: Recovery electronics.
Eggtimer Rocketry: Recovery electronics and GPS rocket tracking that you assemble yourself
Aerocon Systems: Supplier of new and surplus rocket parts and parts to be used for rockets. Supplier of Ratworks parachute releases.
The Rocketman: Manufacturer and supplier of parachutes, drogue chutes, and parachute bags.
Fruity Chutes: Supplier of parachutes, drogue chutes, parachute bags, and parachute harnesses.
Strapworks: Supplier of straps and strap fittings.
Electric Matches and Pyrotechnics
Firefox Enterprises: Supplier of pyrotechnic chemicals.
MJG Technologies: Manufacturer and supplier of electric matches and igniters.
Quick Burst: Supplier of electric matches and igniter.
Skylighter: Supplier of pyrotechnic chemicals.
Electronics and Transducers
DigiKey: Electronic parts and pressure transducers.
Omega: Thermocouples, digital pressure transducers, and load cells.
Tucana Systems: Supplier of AmCell load cells.
Hardware, Tools, Hoses, and Pressure Fittings
Ace Hardware: Hardware, screws, plumbing, and tools.
McMaster-Carr: Supplier of valves, AN-fittings, MS-size O-rings, springs, metal, screws, hardware, pressure relief valves,etc.
Grainger: Supplier of valves, chemicals, screws, hardware, stainless steel fire extinguishers, etc.
Swagelok: Manufacturer and supplier of Swagelok tube fittings.
Titan Fittings: Supplier of single and double lock tube fittings. Supplier of NPT pipe fittings.
Deering Industries: AN-fittings, custom hoses, custom bellows hoses, specialty fittings, and specialty welding.
Seco Seals: 37-degree flared aluminum and copper conical seals.
Generant: Supplier of pressure relief valves.
Bimba: Custom pneumatic actuators.
Gems Sensor & Controls: Supplier of miniature solenoid valves and pressure transducers.
Jefferson: Supplier of solenoid valves.
Industrial Gases and Liquid Oxygen
Electro-Tech Machining: Graphite rod materials for rocket motor nozzles, EDM services for removing broken drill bits in aluminum injectors.
Composite Materials, Resins, and Supplies
Airtech International: Vacuum bagging material, peel ply, breather, and pressure sensitive tape.
West Marine: Fiberglass cloth, epoxy resin, fillers, and putties.
Cotronics: Silica, ceramic, and phenolic tape.
Aircraft Spruce: Fiberglass cloth, carbon cloth, epoxy resin, cloth tape, filler, mold release, AN-fittings, and hardware.
Metals and Cutting Tools
Newman Tools: AN port cutting tools.
M & K Metals: Aluminum tubes and angle.
Industrial Metal Supply (IMS): Aluminum tubes, plate, rod, and angle.
OnlineMetals.com: Stainless steel, steel, aluminum, copper, bronze, and brass as tubes, bars, pipes, rods, sheets, and more.