Prong Buckle

Definition and Overview

A prong buckle is a metal fitting used to fasten belt-like materials. It secures by inserting the prong in the buckle frame into the hole on the other side. By changing the hole position, the waist or strap length can be adjusted in steps. In apparel, it is used not only for belts, but also for cuffs, bag straps, and more.

It is sometimes written as "bijo." In practice, prong buckles are often handled as buckles with a prong, while "bijo" may also be used more broadly to refer to decorative buckles in general. For specifications, state whether a prong is included and how it is used.

Materials and Structure

A typical prong buckle consists of an outer frame, a prong, and a crossbar that supports the prong. The prong is usually a single piece, but depending on the application and design, versions with multiple prongs also exist. On the side that secures the belt, a section is provided to wrap the leather or tape and fasten it by sewing or cap and close post.

Common materials include metals such as brass, iron, zinc alloy die-cast, and stainless steel. The surface may be plated or painted, affecting gloss, color tone, and corrosion resistance. For applications where light weight or the usage environment is important, resin may also be selected.

How Sizes Are Expressed

Prong buckle sizes are generally expressed by the inside dimension of the frame through which the tape or belt passes. Even if the inside dimension matches the tape width, whether it can actually pass through depends also on the tape thickness, folded edge, and bulk created by sewing, so it is important not to judge by width alone.

When designing, choose the inside dimension based on the finished width of the tape or leather being used, and check ease of passage with the actual item. In addition, checking the outside dimension, prong thickness, hole diameter, hole pitch, and the shape of the belt end can help reduce issues with usability and appearance.

• Inside dimension: the inner width of the frame through which the belt or tape passes.
• Outside dimension: the overall size including the frame, related to the design and installation space.
• Prong diameter: related to compatibility with the belt hole and the feel during operation.

Main Applications

Prong buckles are used on matching-fabric belts and attached belts for pants, skirts, dresses, jackets, and more. Because the length can be changed in steps, they are suitable not only for waist adjustment but also for details such as cuffs and tabs on the back, where they serve both to secure openings and to add decoration.

They are also used on bags, hats, around shoes, and on straps for uniforms and outdoor gear. However, in locations where strong loads are repeatedly applied, overall strength design is needed, including not only the prong buckle itself but also the tape, stitching, and hole reinforcement.

Selection and Precautions

Select by checking the belt width and thickness, required adjustment range, product load, and the position that will touch the skin when worn. Thin, delicate frames create a lighter impression, but may not be suitable for thick leather or heavily loaded straps. Use samples to check ease of putting on and taking off, and whether the prong is unlikely to come out of the hole.

With metal products, rust, discoloration, and plating wear may occur due to sweat, moisture, washing, and friction. Based on the material, surface treatment, and usage environment, evaluate corrosion resistance and color transfer as needed. For products using metal accessories, also confirm in advance whether they comply with the needle detector standards of the customer.

Frequently Asked Questions