AN, NAS and MS Bolts are just some of the most popular military and aircraft hardware equipment that are used for most engineering projects that need joining together. These bolts and screws have passed government grade or standard screenings and are mostly used in building aircrafts. AN stands for Air Force-Navy or simply Army Navy. NAS stands for National Aerospace Standards and MS stands for Military Standard. These terms are the universally accepted identification for aircraft hardware. Normal standard bolts rust easily and are not that durable, they wear after only a few years and when this happens, you will end up paying more for repair than if you just invested on good MS bolts and what not.
If you plan to build your own aircraft or plane then you should definitely spend money to make sure you buy only quality parts and that includes MS bolts. It is important to make sure that the bolts, screws and what not have been measured correctly. Correct NAS fittings is important so that your plane will not encounter any problems in the future. Safety should always be on top of the list and this is why it is better to use military standard or grade or more commonly known as MS bolts. Safety has no price, so make sure to think about that when you are building your plane. You should only use hardware that is meant to be used for an airplane, if it has the government's seal of approval and is used by most big companies then you know that it is a good investment. Military standard are called such for a reason. They are sturdy and are proven to be of the best quality. They are made from alloy steel that is stainless and is corrosion resistant.
MS bolts are used to join together aircraft pieces that need the most strength.