Ratchett Torque Wrench Operating Instructions

Ratchet torque wrenches use a special blade-lined rotary piece called a "vane gear" to convert the pressure of compressed gas into rotational force (or "torque"). Known as pneumatic torque wrenches, these tools allow auto mechanics and assembly plant workers to quickly tighten and loosen nuts and bolts with little physical effort. If used improperly, however, torque wrenches can strip bolt heads or even cause serious hand injury.

Prepping the Air Compressor

The owner's manual should specify the ideal operating pressure for your ratchet but, to be on the safe side, use an air compressor rated for at least 100 psi and 3 CFM (cubic feet per minute). Note: do not use pressurized gas from a tank. Even if the tank's gas is "inert," the ratchet is designed specifically for compressed air's weight and density.

Attach one end of a pneumatic hose to the compressor. Then attach the other end to a pneumatic air filter and pressure regulator. Set the pressure regulator to 90 psi or the amount specified by the manufacturer. Finally, attach a second pneumatic hose to the pressure regulator's outlet.

Lubrication

To protect the vane gear and other internal parts, you should always apply the proper lubricant to the tool before use. Hold the body of the tool upside down and squirt 10 drops of pneumatic tool lubricant into the air inlet. Squeeze the trigger (the flat metal lever at the base of the tool) for five seconds to allow the lubricant to flow through the entire system.

Next, you must flush the excess lubricant out of the tool. Attach the pressure regulator's hose to the ratchet's air inlet by pulling back the hose's spring-loaded collar and pushing the inlet nozzle into it. Wrap a heavy rag around the center of the tool, where the plastic handle meets the metal shaft. Once secured, squeeze the trigger for about 10 seconds while the lubricant sprays out onto the rag.

Remove the rag and wipe off the outside of the tool.

Tightening/Loosening Bolts

On the top, front face of the ratchet, you'll find a metal cube with a small, spring-loader ball sticking out on one side. This is the anvil. Push the square opening of the desired socket head onto the anvil to lock it into place. For tightening bolts, check to see that the dial on the side opposite the anvil is set to "Clockwise." For loosening bolts, turn the dial to "Counterclockwise." Note: only turn the dial when the tool is off.

First, slide bolt head as deeply into the socket as it will go. Grasp the top of the ratchet's handle firmly with the thumb, index and middle fingers. To use the ratchet, gently squeeze the long metal trigger with your ring and pinkie fingers.

Release the trigger as soon as the bolt stops turning. Overtightening the piece can crack surfaces or strip the edges off the bolt head, making it impossible to remove later.

Clean-Up

After finishing the job, turn off the air compressor. Remove the hose from the ratchet by sliding back the hose's spring-loaded collar and pulling out the tool.

Finally, turn the the ratchet upside down, squeeze five drops of lubricant into the air inlet and hold the trigger down to let the liquid flow in. The ratchet is now ready for long-term storage.

References

• Pneumatic Air Ratchet Owner's Manual