What Is the Difference Between Pocket Springs and Bonnell Springs?

In a Bonnell unit the coils are hourglass-shaped: wide at each end, narrow at the waist. The top and bottom rings of every coil are laced to the rings of its neighbours by helical wires running the length of each row. Once that lacing is done, what exists is not a set of individual springs but a single interlinked spring surface.

In a pocket unit each coil is enclosed in its own fabric sleeve. The sleeves are joined side by side, but the wires themselves are never tied to one another. When one coil is compressed there is no mechanical path to carry that movement into its neighbour; the coil works within the boundary of its own pocket.

That single difference is the source of every other one: motion transfer, surface response, construction complexity and cost all follow from it. YAYLA manufactures pocket springs; Bonnell springs and zigzag springs are not part of the range. This guide is written so that it still holds for a reader who ends up choosing Bonnell.

The Bonnell unit's first advantage is simplicity. It consists of three things: the coils, the helical wires that lace them, and the border frame. Fewer parts mean fewer process steps and a structure that is easier to repair, and the same simplicity pulls its production cost below that of a pocket unit.

The second is how the surface behaves. Because the coils are connected, the unit spreads load over a wide area and gives a flat surface with the same firmness everywhere. Where the specification asks for a firm, even platform — hotel beds, dormitory and institutional beds, entry-level single models — that is not a shortcoming but precisely the property wanted.

The third is its track record. Bonnell is the longest-serving spring type in mattress manufacturing; the machinery, the spare parts and the labour that knows how to work with it are available almost everywhere. Bonnell is not an obsolete product. It is a different answer to the same problem.

The pocket unit's first advantage is localised response. Wherever load is applied, only the coils under it compress; the ones beside them stay where they were. The surface therefore behaves not as a flat plane but as a profile that follows the outline of whatever rests on it.

The second is reduced motion transfer. Because the coils are not tied together, movement at one point is not mechanically carried into its neighbours. This is the property most noticed in double beds: movement on one side is felt markedly less on the other.

The third is the ability to zone. Since the coils are independent, different parts of the unit can be built with a different wire gauge or a different spring character — a more supportive band at the waist, a more yielding one at the shoulder. In a Bonnell unit the surface works as one piece, so the same distinction cannot be drawn as sharply.

Buyers in Turkey sometimes put zigzag springs on the same list, but a zigzag belongs to a different job. A zigzag — also called a sinuous or S-spring — is a single flat wire bent into a serpentine strip; it is fixed under tension front to back across the wooden or metal frame of a seat and forms the deck beneath the cushion.

So a zigzag is not an alternative to a mattress spring unit: it belongs in sofa and armchair frames, not inside a mattress. YAYLA does not sell zigzag springs either. The only reason they appear here is so they can be set aside when they turn up on a comparison list by mistake.

The choice starts with which property defines the product. If the definition is a flat, firm surface that behaves the same everywhere, Bonnell is the right answer. If the definition is localised support, low motion transfer or a zoned surface, the pocket unit is. Neither description is the better version of the other; they are two different things.

The second question is on the production side: which unit your line is set up for, what labour you have, and what comfort layers go over the unit. A pocket unit's localised response is largely masked if a thick, firm layer is laid on top of it, and in that case the very property the pocket unit was chosen for never reaches the surface.

On the pocket side, the technical points to settle are coil count, spring height and the packing format. These are set per order; for the options available, see the product page or ask us.