SAE/Imperial bolts are denominated by 2 numbers. The first, sometimes preceeded with a "#" is the bolt diameter/size. The second number, separated from the first with a "-", is the number of threads per inch.

We have standardized to use three bolt sizes, #10-32, 1/4-20, and #8-32, though there are other uncommonly used bolts that can be found in the makerspace. In the past, 8-32 was the standard, but we are now moving towards using 10-32 as the general use standard as it is much stronger and easier to find. Avoid using non-standard bolt sizes as it creates hassle due to needing a different sized wrench and hex key/allen wrench.

Metric bolts are standardized to a simple scale denominated by "M[number]" (Ex. M3), where the number is correlated to size.

We only use metric botls with the REV Ultraplanetary system. The ultraplanetary gearboxes are assembled and attached using metric bolts. See the [REV documentation] for assembly instructions.

Head Type	Bolt Size	Wrench Size	Hex Key Size
Socket	#8-32	11/32
Socket	#10-32	3/8	5/32 i think?
Socket	1/4-20	7/16
Button	#8-32	11/32
Button	#10-32	3/8
Button	1/4-20	7/16
Bevel	#8-32	11/32
Bevel	#10-32	3/8
Bevel	1/4-20	7/16

The thread count is listed in the bolt size, but the wrench and hex key sizes are the same regardless of threads per inch. A 10-32 and 10-24 socket head used the same wrench and hex key.

Socket head bolts have a cylindrical head with a hex indent. These are prefered in general use due to their resistance to stripping. This is due to a combination of a deeper and larger hex socket in the head.

In certain cases where clearance and space are considerations, a button head is flatter and has a shorter head. This can allow it to fit in places where a socket head would jut out too far. They also used a different sized hex key compared to the same sized socket head. The reduced head size and depth means it is easier to strip.

Beveled bolts have a flat face and taper down to the threaded portion of the bolt. These are good for when you need the bolt to sit flush with the material you are bolting. A countersink bit should be used to countersink the bevel shape into the material. Do not use if there the hole has not been countersunk as the bevel will not disperse the force applied and will provide a worse attachment. Thse also use a different sized hex key compared to the same size socket head bolt.

Most people should be familiar with Phillips head (its the plus shaped one). Make sure to use the right sized screwdriver and try to avoid using the impact driver on the head to prevent stripping. It's prefered to use the socket attachment on the impact and drive the nut instead, but in some cases this is not possible.

Jam nuts are the basic threaded hexagonal things you put on bolts. They are used to hold things on the bolt.

You should use a wrench to thread them. Crescent, rachet, socket, or even adjustable wrenches are good. Other, sketchier methods like using pliers are not advisable though they may be convient.

Generally, nuts are supposed to be torqued to some specification so they won't unthread themselves under the vibrations. However, this doesn't not work as we are usually working with aluminum which will just bend or get crushed under the load. In that case, you can place two nuts and spin them into each other, "jamming" them, which will stop them from moving.

These are generally not used, but they are simple, cheap, and durable. In most cases, we prefer to use nylon lock nuts.

Nylon lock nuts, or nylock nuts, have a nylon insert on a raised end. The nylon insert stretches over the threads and adds friction and dampens vibrations, preventing the bolt from loosening. These are basically the only nuts we use except in rare cases when we can't find one or there's a unique application.

Wing nuts have wings that stretch up and out from the nut on one end. This provides a hold for you to hand thread the nut on easily. However, other than that they function the same as normal nuts, so they should only be used when something needs to be taken off and put on quickly like bumpers.

Screws are different from bolts in that they are meant to be driven into material and do not use nuts on the other side. These are identifiable by the pointed tip for driving into the material. You should use an impact driver for screws.

Screws are not really used on the robot because we mostly use hollow rectangular aluminum box tubing. However, they are good for non robot contrucution like for field elements, robot cart, shelves and tables, and anytime wood is involved.

Wood screws are probably the most common and what you are already familiar with. They come in lots of shapes and sizes. They can use a flat head, philips, or even torx/star bit. Compared to metal screws, they usually have coarser and larger threads relative to the thickness of the screw compared to metal screws.

For larger/longer screws and when driving into solid wood (not plywood), it is a good idea to drill a pilot hole first. The pilot hole will make it easier to start the screw, keep the screw straight, and prevent splintering or splitting the wood.

We also have some self-tapping screws. These are meant for metal and have a unqiue tip that drills into metal.

There are also lots of sheet metal screws mixed in with the box of screws or in their own packaging. These are for very thin sheet metal. They have much thicker shafts and threads for driving into and holding on in sheetmetal. They can also be used in plastics and wood with a pilot hole due to their thickness.