Torquing and Safety Wiring

Torque

The force or turning effort required to apply tension to a fastener assembly

Torquing

The act of tightening a fastener assembly to a specific value

Measurement of Torque

• Foot-pounds

• Inch-pounds

Micrometer

1. Present desired torque

2. Apply torque

   • Handle will break or click when desired torque is reached

Dial Indicating

1. Prior zero to using

2. May turn either way to apply torque

Torque Wrench Selection

Calibration is not reliable at extreme ends of the torque range, so the required torque should fall between 30% and 80% of wrench range

Scheduled Intervals

Specified in calibration data for wrench

Unscheduled Intervals

Dropped, suspected of being dropped, or mistreated

Hardware Securing

Process of securing all aircraft bolts, nuts, turnbuckles, cap screws, studs, and all other fasteners to prevent loosening by vibration

Safety Wire Common Sizes

• 0.032

• 0.020

Single Wire Style

Used in hard to reach areas and on small, close objects

Double Twist Style

Used where strength is required

Cotter Pins

• Used on castellated nuts, pins, and shafts

• Constructed of stainless steel

Cotter Pin Size Determination

• Length

• Diameter

Always ____ a torque wrench toward you, never ____

pull, push

Do not use a torque wrench to _____, _____, or_____

loosen bolts, nuts, or screws

Do not use a torque wrench for anything except ___ torque

measuring

Pigtail end no more than ____ to ____ bent under to prevent snags

1/2”, 3/4”

Never ____ safety wire

reuse

Always wear _____ to protect your eyes

safety glasses

Report ____ immediately

injuries

Cut safety wire at ____ angles to leave no sharp points

right

Cotter pin fit ___ with ____

neatly, little play

Prong should not extend past ____ of bolt diameter after bent

center

If wrap around method is used, prongs should not stick for the ____ of the nut

sides

Cut all cotter pins at ____ angles to not leave a sharp point

right

Always cover the cotter pin with your hand when cutting to prevent ____ or ____

personal injury, FOD