Identification terminology various aircraft hardware Aircraft hardware is the term used to describe the various types of fasteners and miscellaneous small items used in the manufacture and repair of aircraft Identification Most items of aircraft hardware are identified by their specification number or trade name. Threaded fasteners and rivets are usually identified by AN (Air Force-Navy), NAS (National Aircraft Standard), or MS (Military Standard) numbers. Quick-release fasteners are usually identified by factory trade names and size designations.

Aircraft bolts Most bolts used in aircraft structures are either general purpose, AN bolts, or NAS internal wrenching or close tolerance bolts, or MS bolts. Special bolts are usually identified by the letter “S” stamped on the head.

Aircraft Nuts Aircraft nuts are made in a variety of shapes and sizes No identifying marking or lettering appears on nuts. They can be identified only by the characteristic metallic luster or color of the aluminum, brass, They can be further identified by their construction. Aircraft nuts can be divided into two general groups: non-self-locking and self-locking nuts

Rivets Two of the major types of rivets used in aircraft are the common solid shank type, which must be driven using a bucking bar, and the special (blind) rivets, which may be installed where it is impossible to use a bucking bar. The specifications designate the material to be used as well as the head type, diameter, and length of the rivet. Some of the common standardizing organizations include: AMS Aeronautical Material Specifications AN Air Force-Navy AND Air Force-Navy Design AS Aeronautical Standard ASA American Standards Association ASTM American Society for Testing Materials MS Military Standard NAF Naval Aircraft Factory NAS National Aerospace Standard SAE Society of Automotive Engineers

Screws Commonly used screws are classified in three groups: structural screws, which have the same strength as equal size bolts; machine screws, which include the majority of types used for general repair; self tapping screws, which are used for attaching lighter parts

American and British systems of specifications – Threads British Association or BA screw threads are a largely obsolete set of small screw threads, the largest being 0BA at 6 mm diameter. BA or British Association, a coarse thread series known as BSW or British Standard Whitworth and a fine thread series known as BSF or British Standard Fine.  British Standard Whitworth (BSW) sets out the number of threads per inch for each nominal diameter of screw thread.

American and British systems of specifications – Threads

Drills, tapes and reamers Drill: To bore accurately sized holes in metal parts in order to make attachments and to join parts in an assembly. Reamer: A reamer is a cutting tool designed to enlarge a hole, to produce an accurately sized hole, or to cut a tapered hole. Taps and dies are tools used to create screw threads, which is called threading. Many are cutting tools; others are forming tools. A tap is used to cut or form the female portion of the mating pair (e.g., a nut). A die is used to cut or form the male portion of the mating pair (e.g., a bolt).

GEARS & BEARINGS GEARS BEARINGS 1.These are the devices used for the transmission of the energy over a long distance. 2. Angle of the direction changes to the requirements. 3.It is used for varying the speed. The types are Spur, epicyclic,bevel,helical,step worm,sun and planet. etc., 1.These are the devices used for the lubrication and for the smooth of operation. 2.It is used for reducing the vibration. 3.It is used not for varying the speed. The different types are Plain,ball,roller, etc.,

Identification of all types of fluid line fittings Before making repairs to any aircraft tubing, it is important to make accurate identification of tubing materials