Pliers, Punches, and Wrenches
Pliers and Plier-type Cutters
Includes round nose, duckbill, needle nose, and diagonal cutters
Round Nose: For crimping light metal
Needle Nose: For holding small objects or making adjustments in small spaces
Duckbill: Exclusively for twisting safety wire
Diagonal: For cutting wire, rivets, small screws, and cotter pins
Plier Remarks
Do not use beyond designed capacity as damage to the pliers will result
Never use pliers to turn nuts or bolts
Never use round nose pliers for heavy work on metal
-Note: Do not make pliers work beyond their capacity. The long-nosed variety is especially delicate. It is easy to spring or break them or nick the edges. It can make them practically useless. Never use pliers to turn nuts as they can severely damage a nut
Punches
Solid punch uses:
Marking center for drawing circles
Create starting holes for drilling
Punch small holes in sheet metal
Transfer dimensions from drawing to metal
Removing damaged rivets, pins or bolts
Types of punches
Prick: For placing reference marks on metal
Center: For making small indentation in metal to start twist drill. The point is a 60 degree angle to help hold a drill bit in place
Drive, Starting or Pin: For punching out damaged rivets, pins, and bolts
Transfer: Used to transfer drill hole locations to a piece of metal
Removing a Bolt or Pin
-Use drive punch or tapered punch to drive out stuck bolt or pin until side of punch touch sides of hole
-Use pin punch to further drive the pin or bolt out of the hole without damaging the sides
-Do not use a center or prick punch to drive out stuck bolts
Punch Remarks
Use the correct amount of force when striking a punch to avoid damaging the punch or surrounding material
Use correct punch for correct situation
-Use a prick or center punch to remove a stuck bolt or pin will further lodge the stuck object by spreading
Never use a claw hammer to strike a punch, they are designed to strike nails
-Note: Always use eye protection when a punch is used.
Wrenches
Wide range of types including:
Open-end
Box-end
Socket
Adjustable
Ratcheting
Special Purpose
Allen
Typically made of chrome-vanadium steel and are mostly unbreakable
Designed to be used on nuts, boltheads and specialized screws
Types of Wrenches
Open-end wrenches are non-adjustable with jaws parallel to the handle up to a 90 degree angle. Often, they have a 15 degree angle from being perfectly flat on the jaws to protect your knuckles from hitting the material when turning the wrench
Box-end wrenches have a closed jaw that surrounds the nut or bolt head and can have 4, 6, or 12 points. 4 point is typically used for square plugs
Ratcheting box-end has an internal ratcheting system
Socket wrenches have two parts: sockets which are sized for different size nuts or bolt heads and the handle, on which the socket attaches and has a ratcheting system
Adjustable wrenches are open-end wrenches
Socket wrenches have two parts: sockets which are sized for different size nuts or bolt heads and the handle, on which the socket attaches and has a ratcheting system
Never use a socket and ratchet to loosen stuck bolts
Adjustable wrenches are open-end wrenches and should be your last choice when selecting a wrench to use
Special Wrenches
Crow-foot
Used for situations when nut or bolt cannot be reached with traditional tools
Uses open-ended wrench head that attaches to extension bar. Extension bar then attached to a wrench handle
Flare Nut
Similar to box end, but with a section cut from the head
Used on a flared connection B-nuts, the cut allows the box-end to pass over the tube or line to access the nut grips the B-nut better than a crowsfoot reducing the chance of damage
Hook Spanner
Used on round nuts with notches
The curved arm rests against the nut while the hook on the end fits into the notches on the nut
Includes multiple variations:
U-shaped
End Spanner
Pin Spanner
Face Pin Spanner
Torque
Variations include: Deflecting beam, dial, micrometer, and electronic
Used when a specified amount of torque is required (when too much or too little will result in damage or failure)
Often Resembles a socket wrench set, but with either a dial, set ring, or digital output to:
Set the desired torque, at which point the internal mechanism releases the torque
Indicate the current amount of torque being applied
Due to the high degree of accuracy needed, it is important to:
Always inspect before use
Verify calibration date
Never drop a torque wrench
Never use to break fastener torque
Note: If several nut bolts/studs are used for joining the same part (such as a cylinder head), they are usually tightened in sequence.
-If they are in a circle, torque the bolts that are 180 degrees apart until all bolts have been secured.
-If they are in a line, start with the inner most bolts, bouncing back and forth on each side until all bolts have been secured. This works any stresses to the outside of the bolt line.
Allen
Wrench made of a hexagonal (six-sided) shaped metal shaft with a 90 bend. One end is longer than the other
Used on special screws that contain a hexagonal socket in which one end of the allen wrench is inserted in order to turn the screw
Strap Wrenches
Used when other conventional tools will not fit or grip, or would cause damage to the part when applying rotational force
Consists of handle and plastic covered strap
Inspect Driver
- Impact Driver
Place it on a fastener that is stuck or requires high amount of torque to to loosen, and then strike it with a mallet
The impact of the mallet causes a very small rotation, but with very high-torque
Uses special bits and sockets
Wrench Remarks
Torque wrenches are high precision tools, must be tested for accuracy periodically or when damage/ mishandling is apparent
Torque measurement are visually read during use of deflecting beam, dial, and electronic indicating
For micrometer wrenches, the amount of desired torque us set using a dial, and the operator feels a distinct break or click when the desired torque is reached, not further torque can be applied