These buckles are known as 3-piece because they have 3 parts to them - The Tip, Keeper and Buckle. They are very popular on country style belts' 3-piece buckle refers to a type of buckle that consists of three separate components: a frame, a prong, and a bar. The frame is the outermost part of the buckle that holds the other two components in place. The prong is the piece that fits through a hole in the strap or band to secure the buckle, while the bar is the part that slides into the frame to secure the prong in place.

The size of a 3-piece buckle can vary depending on the specific design and intended use. However, in general, these buckles tend to be larger and more robust than other types of buckles, as they are often used for heavy-duty applications such as horse tack, backpacks, and other outdoor gear.

When selecting a 3-piece buckle, it is important to consider the size and strength of the strap or band that will be used with it. The buckle should be proportionate to the size of the strap, and the prong should fit snugly through the hole without being too loose or too tight.

Overall, a 3-piece buckle is a versatile and durable choice for many different types of projects, and can be found in a variety of materials and finishes to suit different design preferences.