VEX Parts Wiki

Hello everyone! The VEX Parts Wiki is dedicated to teaching about the physical parts VEX and other vendors may sell, their purposes, and possibly replacements. (So far this is just the skeleton, I’ll beef it up once i get the other wikis up and running, but feel free to add on)

Structural Parts


This relates to any parts that are used to construct the frame or layout of a mechanism.

Fastening/Threaded Things


All screws in VEX (with the excpetion of thumb screws and #6-32 hex drive screws) come in sizes ranging from 1/4’’ - 1’’ (in 1/8’’ length steps) and 1’’ - 2.5’’ (in 1/4’’ steps). These are the main fastener

Standard Star Drive

This is the most common type of screw seen in VEX. All these VEX screws are #8-32 star drive screws (also called “torx” screws) made of finished alloy steel. The drive type is not very common, hence why the screws are hard to find. Screwdrivers labeled “torx” or “security torx” are compatible with these screws (the latter features a hole in the middle of the driver to accomodate a different torx head, but will still work with VEX torx screws)
Some alternatives include robosource and McMaster Carr screws. Robosource also has colored screws that color their screw heads based on the screw length. Robosource also offers shoulder screws, which include a non-threaded “shoulder” that fits snugly into metal holes, preventing the screw from shifting and reducing slop on joints.

Loctite Screws

VEX loctite screws are just Standard Star Drive screws brushed with blue loctite. This blue loctite is designed to be removeable (versus the red loctite which is permanent, unless heated to 500 F). This holds the screw in against vibrations and such, preventing it from becoming undone (similar usage as nylock nuts).
The name brand loctite can be found here (make sure you purchase the BLUE one, not the red one, and definitely not their super glue).

Hex Screws

Before the advent of the star drive screw, these were the mainstay of VEX. Made of High Strength Steel, these were quite prone to stripping, and are usually not recommended and most prefer the newer and stronger star drives. If purchasing, be sure to purchase the #8-32 screws, as the #6-32 screws are only compatible with the outdated Cortex electronics.


Couplers are essentially shaft collar screws but longer. They are #8-32 like all standard fasteners. These are often used to connect standoffs to other standoffs or standoffs to shaft collars (especially useful when bracing drivetrains or attaching things at weird angles). These come in 0.5’’ and 1.0’’ lengths.
An alternative source is robosource.


There are four standard nuts in VEX: the unadorned nut, keps nut, nylock nut, and low-profile screws, although the middle two are the most commonly used. All nuts offered by VEX are #8-32 and (insert height srry Im on my phone and can’t access CAD) high. All nuts have six sides, each 0.194’’ long

Standard Nut

Standard VEX nuts are rarely used because they don’t have locking or other special abilities (hence boring). The nuts are 0.112’’ tall with a 0.106’’ thread length. (Lengths: Red - 0.194’‘, Yellow - 0.378’‘, Green - 0.336’')

Keps Nut

These are the most common nuts in VEX. They feature a ring of “teeth” that imprint/grip into the metal/plastic and retain the nut in it’s position. They are also tinner than the standard nylock nut, allowing it to lock screws in tighter places.

Nylock Nuts

Nylock nuts feature a nylon ring on one side of the nut in which the threads of the screw dig in/imprint into to fasten. These are the least likely to fall off screws, but are the hardest to tighten.


Standoffs are great for bracing and attaching things without the use of metal. They are made of lightweight aluminum, so you shouldn’t tigthen them too much lest you get “scars” (deformations in the metal). They are all 0.25’’ hex size. Anything greater than a 1’’ size has a stopper 0.5’’ in in either side that prevents a screw from being tightened past it.
Alternate vendors include robosource’s black standoffs and McMaster-Carr. However, only standoffs up to 2.5’’ are legal for VRC.


All metals in VEX are perforated with 0.1428’‘-0.1820’’ (min and max lengths) square holes spaced 0.5’’ from each other. These are the main structure/frame components of a robot. There are two different metal types: steel (shiny and polished) and aluminum (matte with grainy surface). Steel is stronger and heavier, whereas aluminum is light and easy to bend/cut. Steel is recommended for structure needed to be strong/carry a lot of load or to weigh down your bot, whereas aluminum is used for less-strength focused mechanisms and is much lighter.




Shaft fasteners


The Brain
Smart Port Sensors
3-wire Sensors


Pneumatic Actuator/"Pistons"/Cylinders
The Reservior



VEX is the standard and namesake vendor for competition products.

Robosource originally started as a fundraising initiative

Historical Vendors
Before 2022, there used to be a wide ecosystem of VEX resellers offering lower prices and more/niche products. However, around 2022 VEX closed down it’s reseller system, and many of the loved names died out, such as robotmesh (famous for their coding studio, though shut down so more would use the official VEX one) and idesign solutions. Robosource is the only one still around, but STEM Robotics also lives on as an organization (though doesn’t formally sell parts).

McMaster Carr

McMaster-Carr is a very old company with a colossal catalogue of pretty much every VEX fastener you can think of (with the exception of couplers). They are pretty much one of the main industry standards, and aren’t the cheapest, but one of the most reliable and fastest for a catalogue as wide as them.

SMC Pneumatics
Other People