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Pocket Spring vs Bonnell Spring Units: Technical Comparison for Mattress Makers
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Short answer: in a Bonnell spring unit the hourglass coils are joined by helical lacing wire and work together as one interconnected unit; in a pocket spring unit every coil sits in its own separate cell and moves independently. Bonnell units use thicker wire and spread load over a wide area; pocket units give point-elastic support, zoning options and very little motion transfer. KAR-AS manufactures both types in its own factory in Kayseri, Turkey.
How each unit is built
Bonnell (KAR-AS brand): hourglass-shaped coils of high-carbon steel wire are connected by helical lacing wire and usually held by a border rod, so the whole unit flexes together. Pocket (BESTTEL brand): cylindrical coils are each placed in a separate cell and the cells are joined into a unit, so each coil reacts to the load directly above it.
Comparison table
| Property | Bonnell spring unit | Pocket spring unit |
|---|---|---|
| Construction | Interconnected coils (helical lacing wire) | Independent coils, each in its own cell |
| Support type | Area-elastic: load is shared by neighbouring coils | Point-elastic: each coil responds on its own |
| Motion transfer | Higher | Low |
| Wire diameter (KAR-AS range) | 2.20–2.38 mm (≈ 13 gauge) | 1.20–2.10 mm (≈ 18–14 gauge) |
| Unit height (KAR-AS range) | 100–180 mm | 6–28 cm |
| Count series (KAR-AS) | 110+130 to 150+190 | 650 to 2000 |
| Model options | Normal, framed (Herkül), Hasır; mattress and sofa versions | Zoned, micro, edge-support and double-layer models |
| Typical use | Mattresses and sofas | Mattresses |
| Packaging | Flat-pack pressed or roll-packed, with or without pallets | Flat-pack pressed or roll-packed, with or without pallets |
How manufacturers choose between them
- Feel and support: Bonnell gives a uniform, area-elastic feel; pocket springs follow the body point by point and allow zoning.
- Motion isolation: for double mattresses where partner movement matters, pocket units transfer far less motion.
- Zoning: pocket units can be built with firmer and softer zones (for example under the shoulders and hips); Bonnell units cannot be zoned in the same way.
- Sofas and seating: both are used; Bonnell sofa units are a common choice for seat cushions.
- Logistics: both types can be roll-packed, which reduces the space needed per unit in a container.
What to include in a quotation request
- Spring type (Bonnell or pocket) and model, if known
- Unit size (width × length) and height
- Wire diameter and count, or the target firmness
- Zoning, edge support or double layer (pocket units)
- Packaging preference (flat-pack or roll-packed, pallets)
- Quantity and destination country (minimum order: one full container)
See the model ranges: Bonnell spring units · pocket spring units. Related: wire diameter vs gauge table, glossary of spring terms, OEM & private label, packaging & container loading.
Kayseri / Türkiye
