Proper Care of Torque Wrenches and Screwdrivers

In a recent post, someone mentioned, "We recently had our audit and something came out of it that we didn’t expect. Torque wrenches not calibrated. Now granted, we only use them to tighten machining fixtures on certain equipment but we were still told they needed to be calibrated." Quality requirements for torque equipment are in more demand now. Ensuring the accuracy of torque-based mechanisms is a challenge for most industries. Torque wrenches are subject to wear and tear and in some cases may need to be replaced. Proper calibration ensures that your equipment meets manufacturer's specifications and also is a good way to avoid problems caused by using misaligned torque equipment.

The Interior Mechanisms of the Torque Wrench

The toggle action wrench is the most commonly used torque wrench since it is inexpensive, widely available, and easy to use. The toggle action wrench has a coil spring measuring element built within a rigid housing. Positions of the adjustment screw impose different amounts of spring pressure to a toggling mechanism within the housing.This tool has several advantages over other types:

• One can easily get repeatable applications of torque

• There is no need to see the measuring scale of the wrench when in use

• The drive end is fitted with a ratchet

• Last but not least, it is relatively cheap to buy

While the toggle action wrench is subject to wear, the repeatability remains pretty consistent during a use session although the dialed in accuracy may degrade with improper care.

Proper Care and Maintenance of Your Torque Wrench

The torque wrench is a precision measurement instrument, so make sure you avoid common mistakes that may damage it or put it out of calibration alignment. Here are a few tips:

Don't

• Drop it

• Throw it

• Slide it across the floor

• Leave it unprotected

• Put other tools on top of it

• Use a torque wrench as a breaker bar for loosening fasters or as a hammer

Do

• Wind it down when storing for an extended amount of time.

• For accurate results, one click is enough.

• Check the wrench specifications before using an anticlockwise or clockwise thread to ensure the tool is suitable to prevent a loss of torque control.

• Always use torque fasteners with a smooth, steady pull of the wrench.

• Always position the torque wrench so you are constantly pulling on a level plane.

• Avoid the uppermost and lowermost ranges of any given torque wrench. Staying within the middle 60% of the wrench range yields the best and most accurate results.

• Have your torque wrench calibrated at least once a year if you use it three to four times a month.

Advantages of Calibrating Your Torque Wrench

• Provide repeatable accuracy, saving time, money, materials, and labor.

• Calibrating a torque wrench is the easiest way to avoid broken fasteners.

• Reduce the risk of products failing in service.

• Save money from warranty and rework costs.

Tra-Cal Knows Torque

Tra-Cal calibrates a broad range of torque tools and equipment:

• Manual tools (dynamometric wrenches and screwdrivers, torque wrenches, etc.)

• Powered torque tools (electric, pneumatics, hydraulic)

• Torque meters

• Test benched (torque meters linked to a display)

Tra-Cal's torque capabilities are comprehensive. For example, our typical torque wrench capabilities (with uncertainties) are:

> (4 to 50) in-lbf @ 0.57%

> (30 to 400) in-lbf @ 0.34%

> (80 to 1000) in-lbf @ 0.38%

> (29 to 250) ft-lbf @ 0.38%