Tire Size Designations often feature suffix letters employed by the Tire and Rim Association (TRA) to communicate critical information. These letters play a crucial role in distinguishing tires for specific service conditions, aiding consumers in selecting the right fit for various applications.

Here’s a concise guide to common TRA suffix letters and their definitions:

1. NHS (Not for highway service):
   • Indicates that these tires are unsuitable for highway use, making it clear that they are designed for off-road or specialized purposes.
2. TG (Tractor-Grader tires – Not for highway service):
   • Tailored for tractors and graders, TG-designated tires emphasize their inappropriateness for highway use, helping consumers choose the right tire for heavy-duty equipment.
3. ML (Mining and Logging Tires used in Intermittent Highway Service):
   • ML letters signify tires crafted for the challenging conditions of mining and logging operations. While suitable for intermittent highway use, they are primarily built for off-road environments.
4. DT (Tires primarily for use in sand service):
   • DT-labeled tires are designed specifically for sand service, providing optimal traction and durability in sandy terrains.
5. K (Compactor tire for use on drop center or semi-drop center rims):
   • Tailored for compactors, K-designated tires are engineered for use on drop center or semi-drop center rims, ensuring a seamless fit for compaction equipment.