A torque wrench is a precision tool used to apply a specific amount of torque
(tightening force) to a fastener such as a bolt
or nut.
It ensures that parts are neither too tight
(which can cause damage) nor too loose (which can lead to failure or leaks).
🔧 What Is Torque?
Torque means
the rotational force applied to turn something — like twisting a bolt.
It’s measured in:
- Inch-pounds (in-lb)
- Foot-pounds (ft-lb)
- Newton-meters (N·m)
Example: Tighten a bolt to 45 in-lb means
the twisting force should be 45 inch-pounds.
⚙️ Main Types of Torque Wrenches
1. Beam Type
- How it works: Has a pointer and
scale. The needle moves as you tighten, showing torque on the scale.
- Use: Simple, inexpensive, reliable.
- Common for: Basic automotive,
bicycles, and small machinery.
- ✅ Pros: No need for
calibration, durable.
- ⚠️ Cons: Harder to read
precisely.
2. Click Type
- How it works: You set the
desired torque. When reached, the wrench clicks and slips slightly
to prevent over-tightening.
- Use: Most popular in automotive and
aviation.
- ✅ Pros: Accurate, easy to
use.
- ⚠️ Cons: Must be
recalibrated occasionally; always reset to the lowest value after use.
3. Digital /
Electronic Type
- How it works: Has an electronic
display; beeps or vibrates when torque is reached.
- Use: Precision industries, aircraft
maintenance, and lab use.
- ✅ Pros: Very accurate,
can store readings.
- ⚠️ Cons: Expensive, needs
batteries.
4. Dial Type
- How it works: Has a dial gauge
showing torque value.
- Use: Calibration labs or
high-precision assembly.
- ✅ Pros: Extremely
accurate.
- ⚠️ Cons: Costly,
delicate.
5. Split Beam Type
- How it works: Similar to click type
but easier to adjust and maintain calibration.
- Use: Professional mechanics,
aviation maintenance.
- ✅ Pros: Durable, stays
calibrated longer.
- ⚠️ Cons: Heavier,
costlier.
🔩 Uses of Torque Wrench
|
Field |
Use Example |
|
Automotive |
Tightening
spark plugs, cylinder head bolts, wheel nuts |
|
Aviation |
Fastening engine components, propellers, and airframe bolts |
|
Mechanical / Industrial |
Assembling machines, valves, pumps |
|
Electronics |
Tightening delicate components with small torque |
|
Home Repairs |
Installing bicycle parts, plumbing fittings, etc. |
⚠️ Safety & Best Practices
- Always use the correct torque value (from manual).
- Tighten smoothly — don’t jerk the
handle.
- Stop at the click (for click-type).
- Reset to lowest setting after use.
- Recalibrate regularly for accuracy.