Frame-Style
The most common belt buckle is also not surprisingly the most versatile buckle style for both formal and casual belts. These buckles are available in dimensions from 20 mm to 40 mm in widths. Always choose a solid brass buckle; a solid metal or brass buckle is more durable and sturdy than one that has a hollow interior.
A classical and traditional frame-style buckle usually has the strap sewn or riveted to it. The rivet allows the buckle to be removed and the strap length adjusted to size.
Frame-Style With Clamp Press
Plate-Style
Plate style buckles are usually detachable. The underside of the plate style buckle is a stud or hook which goes through the belt hole. Plate-style buckles are usually decorated and used as a fashion belt for casual outfits.
Box-Frame Buckle
If you have served in the military or police force, you may already be familiar with the box-frame buckle. 
Commonly paired with a strap made of canvas webbing or cotton strap, box frame buckle belts are fashionable items among the young.
The belt strap is usually without holes and is easily attached to the belt by inserting the belt through a clamp press on the underside of the box frame. For this reason, all box-frame buckle belts are sold in free sizes and you may cut the strap according to your desired length easily.
Ring Buckle
Belts with ring buckles are typically fashion belts for women's wear. The strap is fastened through one of two rings which serve as a buckle. Some ring buckles are actually frame-buckles with a stud hook to fasten the belt. Belts with ring buckles have softer and less structured straps such as fabrics or lambskin.
