Manufacturer · Fashion & Home Accessories
Ring sizes are specified by the inner measurement – the clear opening through which the belt passes. For D-shaped and rectangular rings, this is the inner width of the straight side, while for round rings it is the inner diameter. The inner measurement should equal the belt width plus a small allowance for its thickness; the wire thickness is specified separately.
Main ring sizes and how to measure them
When ordering rings, the following parameters are usually used, all in millimetres:
- Inner width (W) – for D-shaped, rectangular, and triangular rings: the clear length of the straight side.
- Inner diameter (ID) – for round rings: the opening at its widest point.
- Outer diameter or width – the overall size, important for design and packaging.
- Inner depth – for D-rings: the distance from the straight side to the curve.
- Wire thickness or cross-section – determines strength and visual weight.
Why inner, not outer measurement?
Two rings with the same outer diameter can have different openings if one has thicker wire. For the belt, only the clear opening matters. Therefore, always specify in your order whether the size is inner or outer – this is the most common cause of misunderstandings between manufacturer and buyer.
How to measure yourself
- Use calipers, not a ruler. For small sizes, a 1 mm difference is significant.
- Measure inside, between the inner edges of the wire.
- For D-rings, measure the straight side; for round rings, measure two perpendicular diameters to check if the ring is truly round or slightly oval.
- Measure the wire thickness where there is no seam.
- Note the wire profile shape – round, flat, or beveled.
How much allowance to leave for the belt
The belt is not infinitely thin. When folded around the ring and sewn, two layers of material enter the opening, and the edges may be folded or stitched. Therefore:
- For thin woven ribbons and grosgrain, the allowance is minimal – the ring is as wide as the ribbon or just slightly wider;
- For dense straps used in backpacks and belts, leave a bit more space to avoid bunching in the corners;
- For leather belts with folded edges, the allowance is largest because leather is stiff and does not compress.
The safest method is to measure the finished belt – including folds and seams – and check a ring sample with it.
Popular ring sizes
| Inner Width | Suitable Belt | Typical Use |
|---|---|---|
| about 10–15 mm | Narrow ribbons, cords, thin leather straps | Wallets, jewellery, dress belts |
| about 20 mm | Straps and belts around 20 mm | Ladies’ bags, small dog collars |
| about 25 mm | Straps around 25 mm | Shoulder bags, textile belts, backpacks |
| about 30 mm | Belts and straps around 30 mm | Belts, sports bags |
| about 40 mm | Wide belts and straps | Men’s belts, shopping bags |
| about 50 mm | Wide ribbons | Travel and tactical bags, harnesses |
The table is indicative. The exact size depends on the thickness and stiffness of the specific belt.
Product size and proportions
Size is not only a technical but also a visual decision. A small ring on a large bag looks accidental, while a massive ring on a delicate dress feels heavy. For fashion items, designers often choose thicker wire or a flat profile to emphasize the ring without changing the belt width. For belts, ring size is usually coordinated with the buckle, and for straps – with the width of the strap.
Split ring sizes for keychains
Keychain rings are measured differently – usually by outer diameter, with width and thickness of the flat wire specified separately. There is no allowance for the belt here, but it is important how many keys or charms they must hold and how easily they open. Thicker wire holds more securely but is harder to open.
Wire thickness – how to choose
Wire thickness is rarely mentioned but determines both strength and character of the ring. Thin wire looks delicate and suits dresses, lingerie, and small accessories. Medium thickness is standard for ladies’ bags and textile belts. Thick wire and solid moulded profiles are chosen for men’s belts, backpacks, and work or military style items. The ratio between wire thickness and belt width should look natural – if in doubt, compare two samples on the actual product.
Allowable deviations
In mass production of rings, there are small size deviations, especially for wire-bent models. If the belt fits the ring exactly, even a small deviation can make some rings unusable. Therefore, size allowance is not only for convenience but also for production stability. When ordering by drawing, specify which sizes are critical and what tolerance you accept.
How to specify size in your inquiry
To get an accurate quote, specify:
- Ring shape;
- Inner width or inner diameter in mm;
- Wire thickness or desired profile;
- Belt material and its thickness;
- Finish and approximate quantity.
If you have a ready ring or belt, the easiest way is to send a sample or a photo with caliper next to it.
Rings by size from Polkom
Polkom is a Bulgarian manufacturer and wholesaler of haberdashery and accessories for fashion, furniture, footwear, and bags with over 30 years of experience. We offer rings in a wide range of sizes and shapes, and can produce custom sizes to your drawing if needed. Samples are made quickly, and delivery is across the EU. Send an inquiry with your sizes and we will prepare an offer.
