mattresses comparison
Pocket sprung vs Open coil (Bonnell)
Evergreen URL: /compare/pocket-sprung-vs-open-coil
In short
Pocket sprung mattresses encase each coil in fabric so springs act more independently. Open-coil Bonnell units lace hourglass springs into one wire grid, so load shares across the lattice. Expect lower movement felt from a partner and finer moulding to shape from pockets; open coil remains common where cost-efficient interconnected support is the design goal.
Both are innerspring systems. The decisive difference is whether coils are pocketed or mechanically linked. Spring count marketing applies mainly to pocket units and must be read with mattress size.
Key differences
| Criterion | Pocket sprung | Open coil (Bonnell) |
|---|---|---|
| Coil arrangement | Each coil in its own fabric pocket | Coils knotted/laced into a continuous grid |
| movement felt from a partner | Typically lower | Typically higher because of shared wire paths |
| Classic geometry | Barrel or cylindrical pocket coils | Hourglass Bonnell coils with helical lacing |
| Edge behaviour | Often reinforced with foam foam border | Border rods and padding define the perimeter |
Pocket sprung may suit if…
- You want more independent support zones
- Partner movement is a primary concern
- You are comparing mid-to-higher spring counts by density
Open coil (Bonnell) may suit if…
- You are studying traditional open-spring engineering
- Budget constructions with interconnected grids are under review
- Maximum coil independence is not the priority
Frequently asked questions
- What does open coil mean?
- Open coil (often Bonnell) means springs are joined into one unit rather than individually pocketed. The linked spring grid transfers more force sideways than a pocket system.