Five Common Causes of Fastener Failure

Fasteners may be relatively small, but they play a critical role in keeping your equipment running safely and reliably. When a fastener fails, the results can range from minor rework to major downtime, or even serious safety risks. For industrial managers and procurement teams, understanding why fasteners fail is the first step to preventing costly problems.

Fasteners are designed to handle specific loads and conditions. When those limits are exceeded, or when the wrong fastener is used, they can fail with little or no warning. Most fastener issues fall into a few common categories. Recognizing them early can help you avoid bigger problems down the line.

1. Fatigue Failure

Fatigue is one of the most common causes of fastener failure. It happens when a fastener is exposed to repeated stress or vibration over time. Even if the load is below the fastener’s maximum strength, constant cycling can cause small cracks to form. Eventually, those cracks grow more and more until the fastener breaks. Your team can prevent this by using fasteners designed for dynamic loads and applying proper torque to maintain correct clamping force. You could also consider using thread-locking methods to reduce the long-term effects of vibration.

2. Overloading

Overloading occurs when a fastener is subjected to more force than it was designed to handle. This can happen suddenly or gradually as conditions change. When overloaded, fasteners may stretch, deform, or fail completely. Some common causes include using undersized fasteners, incorrect torque application, and unexpected increases in load. To prevent a critical fastener failure, be sure to select the correct size and grade for the application and regularly inspect your high-stress connections.

3. Loosening Due to Vibration

In many cases, equipment is exposed to constant vibration while working. Over time, this can cause fasteners to loosen and become unsafe, even if they were installed correctly. Loose fasteners reduce clamping force and can lead to joint failure. However, there are many anti-vibration fastener solutions to choose from. After finding which solution is best for your equipment, it’s important to monitor the vibration levels in critical equipment and monitor any changes.

4. Corrosion

Corrosion weakens fasteners over time, especially in harsh environments. Moisture, chemicals, and temperature changes can all speed up the process. And, as you can guess, the speed and severity of corrosion vary greatly. As it progresses, the fastener loses strength and becomes more likely to fail under normal loads. However, there are corrosion-resistant materials or coatings that you can use to prevent this. You should also be sure to store your fasteners in temperature-controlled, low-moisture areas. For maintenance, you should consistently inspect and replace necessary components in corrosive environments.

5. Improper Installation

Even the highest-quality fastener will fail if it’s not installed correctly. Improper torque, misalignment, or poor technique can all lead to big problems down the road. Over-tightening can damage the threads, while under-tightening allows movement and damage over time. It’s important that workers are trained on the proper installation methods, as explained in manufacturer specifications. To reduce human error, you can also choose to use calibrated torque tools to take the guesswork out of it.

The Cost of Fastener Failure

A single fastener failure can impact your entire operation. It leads to unexpected downtime, increased maintenance costs, damaged equipment, and a safety risk for workers. This highlights an important point: choosing the lowest-cost fastener can lead to higher costs over time. Preventing fastener failure starts with a proactive mindset. By understanding common failure modes, you can make smarter decisions about product selection, installation, and maintenance.

“Fastener failures are rarely random,” says Scotty Rushing, Vice President of Fastener Sales at Martin Supply. “In most cases, they can be traced back to load, environment, or installation. When you address those factors early, you prevent bigger issues later.”

Fasteners may seem like a small part of your operation, but their impact is significant. By choosing the right components and using them correctly, you can improve reliability, reduce downtime, and keep your team safe.

Start by asking: Are our fasteners matched to the demands of our application, or are they an unnecessary risk?

To learn how we can help, contact your Martin Sales Rep or call 800.828.8116.