Load pin, load shackle, and dynamometer are not used for the same purpose. Although all three can serve in tension or force measurement, mechanical integration, load path, portability, and safety requirements differ. For the correct choice, not only the capacity but also the connection geometry and whether the measurement is continuous or temporary should be considered.
What is a load pin?
A load pin is a sensor that is installed to replace an existing pin or shaft and measures the shear force acting on it. It provides measurement in crane sheaves, rope connections, cylinder joints, anchors, and special machines without significantly altering the structure. In most applications, the pin size, bearing clearance, load direction, and fixation to prevent rotation are specially designed.
What is a load shackle?
Load shackle is a bow-shaped solution with an integrated load measurement sensor. It can be added to lifting points more quickly and is useful for temporary or mobile tests. Physical similarity to a standard shackle does not imply the same usage under all conditions; the working load limit, safety factor, pin orientation, and manufacturer instructions should be followed.
What is a dynamometer?
A tension dynamometer or crane scale is a portable device connected to the load line that mostly shows the weight on a local display. Some models offer wireless handheld terminals, recording, and alarms. The sensor, electronics, and display can be integrated into one system; a load pin usually works with an external indicator or transmitter.
Basic differences
| Criterion | Load pin | Load shackle | Dynamometer |
|---|---|---|---|
| Integration | In place of machine pin | To the shackle connection | Independent device on load line |
| Usage | Continuous/OEM measurement | Fixed or temporary measurement | Portable testing and weighing |
| Indicator | Usually external | Can be wired/wireless | Mostly integrated |
| Custom design | Often needed | Standard dimensions common | Ready capacity options |
Critical dimensions for load pin selection
Pin diameter, distance between bearings, load zones, fastening method, and cable exit direction must be known. Double shear and single shear conditions are not the same. The existing pin should not be copied just by outer dimensions; the material, heat treatment, stress, and measurement area should be determined by engineering calculation.
Considerations for load shackle selection
The working load limit should not be confused with the sensor capacity. Shock load, side load, and angled pull limits are checked. The sensor area on the pin should not contact ropes or equipment incorrectly; the shackle body must be able to align freely.
Wired or wireless?
In fixed machines, wired signals can provide long-term stability and continuous power advantages. In mobile lifting applications, a wireless system reduces the risk of cable damage. In wireless selection, battery life, radio range, the number of devices on the same site, data loss behavior, and local frequency regulations are evaluated.
Safety and calibration
In lifting applications, the measuring device is also part of the load path. Certification, safety factor, overload history, and periodic inspection are important. Calibration should be performed as close as possible to the actual usage direction and connection geometry. Side load or angled pull affects both the measurement and mechanical safety.
Which solution should be chosen when?
- Continuous force monitoring through the existing machine pin: load pin
- Adding quick measurement to the hook connection: load shackle
- Portable load testing on site and reading from the screen: dynamometer
- Continuous process data to PLC: load pin or load shackle with transmitter
- Wireless monitoring of multiple lifting points: compatible load shackle system
Frequently asked questions
Can a load pin be installed directly instead of a standard pin?
Even if the dimensions match, the load direction, bearing, and material should be verified before installation. Most applications require technical review.
Is a load shackle the same as a crane scale?
No. A load shackle is a measurement link; a crane scale is mostly a complete device that contains a display and weighing electronics.
Does side pull measurement affect it?
Yes. The product should only be loaded in the allowed direction, and side load limits should not be exceeded.
Relationship with load cells
Load pin and load shackle apply the load cell principle, which converts force into an electrical signal, in different mechanical bodies. While a classic load cell is selected according to platform or tank installation, a load pin is integrated into the existing pin connection; a load shackle is integrated into the lifting equipment. Therefore, in all three solutions, capacity, safety factor, accuracy, IP rating, and calibration should be evaluated together.
If the geometry of the application is suitable for the use of a standard load cell, a classic load cell may be more economical. If a pin or shackle connection is required, selecting a specially sized load pin or load shackle allows measurement to be made without disrupting the load path.
You can review pin-type load cells; for special dimensions and lifting applications you can contact the Kobastar engineering team.