Familiarization of Aircraft Tools

GENERAL PURPOSE TOOLS

HAMMERS AND MALLETS

• METAL HEAD HAMMERS
  • Sized according to the weight of the head without the handle.
• SOFT-FACED HAMMER 
  • For soft metals
  • Striking surface made of wood, brass, lead, rawhide, hard rubber, or plastic. 
  • Should not be used for striking punch heads, bolts, or nails. If used: ruin the hammer.

SCREWDRIVERS

• Classified by its shape, type of blade, and blade length.
• PURPOSE: Loosening or tightening screws or screw head bolts.
• Select the largest screwdriver whose blade will make a good fit in the screw.
• Common type: must fill at least 75 percent of the screw slot.
• If wrong sized is used, it cuts and burrs the screw slot.

PLIERS AND PLIER-TYPE CUTTING TOOLS

• Pliers used extensively in aviation for the job of safety wiring.
  • DUCKBILL
    • Resemble a “duck’s bill” in that the jaws are thin, flat, and shaped like a duck’s bill
    • Used exclusively for twisting safety wire

• DIAGONAL
  • Usually referred to as diagonals or “dikes.” 
  • A short-jawed cutter with a blade set at a slight angle on each jaw. 
  • This tool can be used to cut wire, rivets, small screws, and cotter pins.
  • 

• Other pliers used most frequently in aircraft repair work:
  • NEEDLE-NOSE
    • Have half round jaws of varying lengths
    • Used to hold objects and make adjustments in tight places. 

• ROUND-NOSE PLIERS
  • Used to crimp metal
  • Not made for heavy work because too much pressure will spring the jaws, which are often wrapped to prevent scarring the metal. 

PUNCHES

• To locate centers for drawing circles
• To start holes for drilling
• To punch holes in sheet metals
• To transfer location of holes in patterns
• Remove damaged rivets, pins, or bolts.
• SOLID PUNCHES – classified by the shape of their points
• HOLLOW PUNCHES 

WRENCHES

• Used in aircraft maintenance
• CHROMEVANADIUM STEEL
  • One of the most widely used metals for making wrenches
  • Wrenches made of this metal are almost unbreakable. 
• CLASSIFICATION
  • OPEN-END WRENCHES
    • Solid, nonadjustable wrenches with open parallel jaws on one or both ends
    • These wrenches may have their jaws parallel to the handle or at an angle up to 90°; most are set at an angle of 15°
    • Designed to fit a nut, bolt head, or other object, which makes it possible to exert a turning action
  • BOX-END WRENCHES
  • SOCKET WRENCHES
  • ADJUSTABLE WRENCHES
  • RATCHETING WRENCHES
  • SPECIAL WRENCHES
• ALLEN WRENCH
  • Seldom used
  • Required on one special type of recessed screw
• TORQUE WRENCH
  • Used when definite pressure must be applied to a nut or bolt as it is installed
  • Precision tool consisting of a torque indicating handle and appropriate adapter or attachments
  • It measures the amount of turning or twisting force applied to a nut, bolt, or screw.
• STRAP WRENCHES
  • Can prove to be an invaluable tool for the Aircraft Mechanic
  • By their very nature, aircraft components such as tubing, pipes, small fittings, and round or irregularly shaped components are built to be as light as possible, while still retaining enough strength to function properly. 
  • The misuse of pliers or other gripping tools can quickly damage these parts. If it is necessary to grip a part to hold it in place, or to rotate it to facilitate removal, consider using a strap wrench that uses a plastic covered fabric strap to grip the part.

IMPACT DRIVERS

• Struck with a mallet, the impact driver uses cam action to impart a high amount of torque in a sharp impact to break loose a stubborn fastener. 
• The drive portion of the impact driver can accept a number of different drive bits and sockets. 
• The use of special bits and sockets specifically manufactured for use with an impact driver is required.

METAL CUTTING TOOLS

HAND SNIPS

COMMON TYPES:

• STRAIGHT SNIPS  
  • Used for cutting straight lines when the distance is not great enough to use a squaring shear
  • For cutting the outside of a curve
• CURVED, HAWKSBILL, & AVIATION SNIPS
  • For cutting the inside of curves or radii. Snips should never be used to cut heavy 
•  On the image on the right
  • Green – Right Hand snip, sheet metal
  • Yellow – Straight Hand snip
  • Red – Left Hand snip 

HACKSAWS

• The common hacksaw has a blade, a frame, and a handle. 
• 
• STYLES OF HANDLE
  • Pistol grip
  • Straight
• Hacksaw blades have holes in both ends; they are mounted on pins attached to the frame. 
• When installing a blade in a hacksaw frame, mount the blade with the teeth pointing forward, away from the handle. 

CHISELS

• A hard steel cutting tool that can be used for cutting and chipping any metal softer than the chisel itself. 
• It can be used in restricted areas and for such work as shearing rivets or splitting seized or damaged nuts from bolts.

FILES

• Most files are made of high-grade tool steels that are hardened and tempered. 
• They are known either by the cross section, the general shape, or by their particular use. 
• The cuts of files must be considered when selecting them for various types of work and materials. 

Type of Files 

Parts of a Hand File

DRILL

• For holding and turning twist drills
• 4 TYPES OF PORTABLE DRILLS USED IN AVIATION
  • HAND DRILL
    • Holes 1⁄4 inch in diameter and under can be drilled using hand drill.
    • Also known as “egg beater”
  • BREAST DRILL
    • Designed to hold larger size twist drills than the hand drill
    • A breastplate is affixed at the upper end of the drill to permit the use of body weight to increase the cutting power of the drill. 
  • ELECTRIC AND PNEUMATIC POWER DRILL
    • Available in various shapes and sizes to satisfy almost any requirement. 
    • PNEUMATIC POWER DRILLS
      • Preferred for use around flammable materials, since sparks from an electric drill are a fire or explosion hazard. 
  • TWIST DRILL
    • A pointed tool that is rotated to cut holes in material.
    • It is made of a cylindrical hardened steel bar having spiral flutes (grooves) running the length of the body, and a conical point with cutting edges formed by the ends of the flutes.

Drill Types

REAMERS

• Used to smooth and enlarge holes to exact size
• Hand reamers have square end shanks so that they can be turned with a tap wrench or similar handle. 

COUNTERSINK

• A tool that cuts a cone shaped depression around the hole to allow a rivet or screw to set flush with the surface of the material. 
• Made with various angles to correspond to the various angles of the countersunk rivet and screwheads
• The angle of the standard countersink is Countersink 100°

TAPS AND DIES

• TAP
  • Used to cut threads on the inside of a hole
• DIE
  • For cutting external threads on round stock
• They are made of hard tempered steel and ground to an exact size. 
• 4 TYPES OF THREADS THAT CAN BE CUT WITH STANDARD TAPS AND DIES
  • National Coarse
  • National Fine
  • National Extra Fine
  • National Pipe

LAYOUT AND MEASURING TOOLS

RULES

• Made of steel and are either rigid or flexible. 
• The flexible steel rule will bend, but it should not be bent intentionally as it may be broken rather easily.
• INCH – the unit of measure most used in aircraft work. It may be divided into smaller parts by means of either common or decimal fraction divisions.

COMBINATION SETS 

• A tool that has several uses
• It can be used for the same purposes as an ordinary tri-square, but it differs from the trisquare in that the head slides along the blade and can be clamped at any desired place. 
• Combined with the square or stock head are a level and scriber. The head slides in a central groove on the blade or scale, which can be used separately as a rule.

SCRIBER

• Designed to serve the aviation mechanic to scribe or mark lines on metal surfaces.
• The scriber is made of tool steel, 4 to 12 inches long, and has two needle pointed ends. 
• One end is bent at a 90° angle for reaching and marking through holes.

DIVIDERS AND PENCIL COMPASSES

• Dividers and pencil compasses have two legs joined at the top by a pivot. 
• They are used to scribe circles and arcs and for transferring measurements from the rule to the work. 

CALIPERS 

• Used for measuring diameters and distances or for comparing distances and sizes
• 3 COMMON TYPES OF CALIPERS
  • Inside caliper
  • Outside caliper
  • Hermaphrodite caliper – such as gear tool calipers

Micrometer Calipers 

• 4 TYPES
  • Outside micrometer
  • Inside micrometer
  • Depth micrometer
  • Thread micrometer

Figure 21. Outside Micrometer

Slide Calipers 

• Often used to measure the length of an object
• Provides greater accuracy than the ruler.
• It can, by virtue of its specially formed jaws, measure both inside and outside dimensions. 
• The jaw is slid along a graduated scale, and its jaws then contact the inside or outside of the object to be measured.
• The measurement is then read on the scale located on the body of the caliper, or on the LCD screen.

HANDLING OF AIRCRAFT HAND TOOLS

AIRCRAFT HARDWARE – Review 

Aircraft hardware describes the various types of fasteners and miscellaneous small items used in the manufacture and repair of aircraft. The importance of aircraft hardware is often overlooked because of its small size; however, the safe and efficient operation of all aircraft depends on the correct selection and use of aircraft hardware. Today there are more than 30,000 different fasteners available for aerospace applications. 

Rivet  

A metal pin with a formed head on one end. A rivet is inserted into a drilled hole, and its shank is then deformed by a hand or pneumatic tool. Rivets create a union at least as strong as the material being joined. 

Basic Types: 

Solid Shank Rivets – used since sheet metal was first utilized in aircraft, and remains the single most used aircraft fastener today 

Blind Rivets – installed with access to only one end of the rivet. 

Special Fasteners  

High strength and light weight fastener that can be used in place of conventional AN bolts and nuts. Held in place by a collar, squeezed into position instead of being screwed on like a nut. Examples are Lock bolt, Hi-Lok bolt, Hi Lite fastener, CherryBUCK, Taper Lok, Hi Tigue fastener and Jo bolt. 

Threaded Fastener  

Unlike rivets, may be disassembled and reassembled to an almost infinite number of times. 

Basic Types: 

Standard Aircraft Bolt – used for airframe structural applications  

Aircraft Nut – equipped with some sort of locking device to prevent them from loosening and falling off.  

Screws – most commonly used threaded fastener in aircraft, typically installed with a loose-fitting thread, and the head shapes are made to engage a screwdriver or wrench 

Pins 

Used in shear applications and for safetying. 

Washer  

Provide bearing surface area for nuts, and act as spacers or shims to obtain the proper grip length for a bolt and nut assembly. 

Control Cables  

Used to actuate flight and engine controls from the cockpit.