The Importance of Hardened Raceways

Why is Hardening Relevant in the Caster Industry?

The hardening process is critical for increasing the durability and lifespan of caster raceways. By enhancing their resistance to wear, impact, and stress, hardened raceways prevent issues like cracking, brinelling (surface indentations caused by ball bearings), and excessive play in the bearing system. Without proper hardening, these issues can lead to premature caster failure, increasing downtime and replacement costs.

Common Raceway Finishes

Caster raceways are available in three primary finishes:

1. Un-treated or Non-hardened: These are not suitable for Kingpinless casters as they provide no durability improvements.
2. Through Hardened: This method hardens the entire metal piece, offering improved durability but less resistance to stress and impact.
3. Case Hardened: This technique hardens only the outer surface, creating a strong outer shell while maintaining a flexible core, making it the optimal choice for Kingpinless casters.

Case Hardening: The Superior Solution

Case hardening enhances the surface of the metal by infusing elements like carbon, nitrogen, or boron into the steel at high temperatures. This creates a harder outer layer while preserving the malleability of the inner core. The process involves multiple steps, including heating, carburization, and quenching, to achieve the desired hardness and depth.

The benefits of case hardening include:

• Superior resistance to wear and brinelling.
• Enhanced ability to withstand impact forces.
• Reduced risk of catastrophic failure under stress.

Through Hardening: Durable but Rigid

Through hardening strengthens the entire metal piece by quenching it rapidly after heating. While this improves durability, the lack of flexibility increases susceptibility to cracking under heavy impact. This makes through-hardened raceways less ideal for demanding applications.

The Risks of Unhardened Raceways

Unhardened raceways wear down quickly, leading to brinelling and performance issues such as:

• Reduced service life.
• Swivel chatter and inability to rotate smoothly.
• Poor ergonomics.
• Complete caster failure.

These problems result in higher long-term costs due to frequent replacements and increased downtime.

Hardened vs. Unhardened Raceways: A Case Study

In a comparative test using ICWM standards, two Kingpinless raceways—one hardened and one unhardened—were subjected to a 2-hour drum test at 1,500 pounds with obstacles:

• The unhardened raceway showed significant brinelling, rendering it unusable after the test.
• The hardened raceway exhibited no signs of wear, demonstrating its superior performance and durability.

Summary

Choosing the right hardening process is essential for achieving maximum performance and longevity in Kingpinless casters. While untreated raceways may lower upfront costs, they lead to higher long-term expenses due to frequent replacements. Through-hardened raceways offer improved durability but are less resilient to stress. Case-hardened raceways stand out as the best option, providing unmatched resistance to wear and impact forces.

At Caster Technology, we are committed to delivering top-quality products. Our Kingpinless casters utilize case-hardened raceways to ensure optimal performance, reliability, and return on investment. Trust us for your caster needs and experience the difference that over four decades of expertise can make.