Uses and Advantages of Load Pins

The Uses & Advantages of Load Pins: Discover Their Many Functions and Applications

A load pin is a sensor utilized to measure force or weight in various research, control, measurement and testing applications. The load pin force sensor converts a force into an electrical signal. The load pins provide durable and accurate measurement, even in extreme environments such as space, oceans, mines, and deserts, amongst others. An example of the value of load pins, due to their design, is identifying applied forces, and measuring and preventing overloads transferred through the pin joints.

A key benefit of force sensors, especially load pins, is the use of internal strain gauges. Developed by Strainsert and patented, this internal gauge technology significantly expands the applications of load pins. This proven technology has demonstrated its reliability and effectiveness for more than six decades.

This functionality is achieved through the pin's design, which includes a small internal cavity along its neutral axis to accommodate and safeguard the internal components, keeping the gauges isolated from external conditions. Additionally, load pins are crafted from high-strength stainless or alloy steel to enhance their linearity and ensure consistent performance.

While standard load pins are suitable for many uses, the growing diversity of applications has made custom load pins increasingly essential. The option to acquire load pins tailored to specific requirements offers a significant benefit. Strainsert has streamlined the custom design process, enabling efficient and cost-effective production to meet tight deadlines.

How Do Load Pins Function?

Load pin strain gauges are usually arranged in a Wheatstone bridge setup. With a constant voltage supply, this configuration produces a changing output voltage that corresponds to the force applied to the elastic element. Therefore, a load pin converts mechanical input into an electrical signal by undergoing several physical transformations.

The applied force translates to mechanical stress, based on the fundamental equations of strength in materials science.
This stress is converted into strain following Hooke's Law.
Strain leads to a change in relative resistance.
The change in relative resistance results in a change in output voltage through the Wheatstone bridge setup.

In essence, when a force is exerted on the Load Pin, it causes deformation. This deformation is sensed by the strain gauges and is subsequently converted into an electrical signal that is measurable via the Wheatstone bridge.

Applications for Load Pins

Quantifying forces on a structure often requires costly and complex equipment, especially in industrial and heavy-duty applications. Load pins offer an efficient, reliable solution by integrating directly into mechanical assemblies, replacing standard, non-instrumented pins or shafts within the load path. These specialized force transducers allow for seamless and accurate real-time load monitoring and load measurement without significantly modifying existing designs. When mechanical force is applied to these instrumented load pins, precision strain gauges embedded within the pin detect deformation and generate an electrical signal. This signal enables highly accurate measurement of applied loads, even under extreme stress, cyclic loading, or overload conditions commonly encountered in demanding environments.

Load pins—sometimes referred to as shear pin load cells or force sensing pins—are essential in a wide range of industries requiring accurate measurement of tension, compression, and shear forces. Their robust construction, stainless steel or alloy build, and versatility make them ideal for environments where standard load cells or force sensors may not fit or cannot withstand harsh conditions. Below are common load pin applications encompassing both industrial and aerospace sectors:

Bearing Blocks in cranes and heavy machinery
Brake Anchors in industrial hoists and elevators
Structural Tests for bridges and buildings
Flight Simulators for pilot training and research
Winch/Crane/Lifting Systems for safe material handling
Landing Gear Clevis Joints in commercial and military aircraft
Mooring Lines/Lanyards in marine and offshore oil rigs
Sprocket/Pulley Axles for conveyor systems and automated manufacturing
Bombay/Cargo Doors in aircraft and maritime vessels
Railroad/Towbar Connections for railway operations and airport ground support
Armament Suspension Systems in defense applications
Rocket Reaction Forces for aerospace testing
Aircraft Wing Joints for structural integrity monitoring
Conveyors in bulk material handling and logistics
Test Machines for R&D and quality control
Hydraulic Actuators in industrial automation
Nuclear Fuel Rod Control for power generation
Robotic Pin Joints in automation and manufacturing robots
Sheave Axles for cable and winch tension measurement
Ground Support Equipment in aircraft servicing and logistics

In addition to these standard applications, load pins are often used in dynamic force analysis, preventative maintenance, and safety-critical monitoring. For example, integrating wireless load pin solutions allows real-time data logging and remote monitoring of crane overload, winch line tension, or machinery wear—helping to prevent equipment failure, ensure operator safety, and optimize maintenance schedules.

Why Choose Load Pins?

Load pin technology offers distinct advantages for OEMs, system integrators, and facility operators seeking to improve operational efficiency, compliance, and safety. Benefits include:

Direct force measurement within existing assembly designs
Easy retrofit and custom engineering for unique applications
High environmental resistance—ideal for offshore, mining, and nuclear facilities
Minimal disruption to mechanical structure
Accurate data for load certification, overload protection, and regulatory compliance
Connectivity to data acquisition systems, PLCs, or industrial IoT platforms

Whether you need a custom load pin solution or a standard pin load cell, these high-precision sensors are critical to optimizing system performance and safety. For expert advice on selecting the right load pin, understanding calibration requirements, or integrating load monitoring into your application, consult with leading load cell manufacturers or an instrumentation specialist.

Typical Features of a Load Pin

Constructed from durable stainless steel or other high-strength alloy steels, load pins offer excellent corrosion resistance. This makes them suitable for deployment in extremely challenging environments.

Many load pin systems come with built-in thermal compensation. They are designed for straightforward installation and upkeep, offering a cost-effective solution for challenging load measurement scenarios. An optional wireless transmitter for these load pins features integrated electronics, allowing for cable-free monitoring. When correctly installed and calibrated, load pins can serve as direct replacements, reducing installation expenses and eliminating the need for extra hardware components in the load path.

Why is Calibration of Load Pins Essential?

Load pins play a vital role across various sectors such as aerospace, marine, oil and gas exploration, military, aviation, and automotive industries. Ensuring accurate force measurements is essential for addressing product liability and safety concerns. Adhering to traceability standards aligned with NIST is often necessary to meet ISO and AS certification requirements.

Load pins can experience degradation over time due to factors such as usage, mishandling, drift, or aging. To maintain accuracy, it is essential to calibrate them periodically. Wear and tear can affect the load pin’s reliability, potentially causing issues from electrical interference, mechanical effects, instrumentation faults, or loose connections. Additionally, neglecting to inspect or clean load pins can lead to operational problems, as even in clean settings, particulate matter can accumulate. Conducting regular annual calibrations ensures that the load pins continue to perform at their best.

Ştefănescu, D. M. (2020). *Handbook of Force Transducers: Features and Uses*. Springer Nature.

Ştefănescu, D. M. (2011). *Handbook of Force Transducers: Fundamentals and Parts*. Springer-Verlag.