Customized Bonnell Coil Spring Unit Steel Bonnel Spring For Mattress

Product Descriptions

What is a Bonnell Spring Unit?

Bonnell coils are the oldest and most traditional type of mattress spring. They are an hourglass-shaped,

knotted, wire spring connected in a continuous grid by helical wires (strings of smaller coils). They are

known for being firm, supportive, and the most cost-effective innerspring option.

Key Customization Options for Bonnell Spring Units

When you order a customized Bonnell unit, you are specifying the following parameters:

1. Wire Specifications

• Wire Gauge (Thickness): This is the most critical factor for firmness.

  • Lower Gauge Number = Thicker Wire = Firmer Feel (e.g., 12.5 gauge)

  • Higher Gauge Number = Thinner Wire = Softer Feel (e.g., 15 gauge)

  • Common Range: 12.5 ga (~1.7mm) to 15 ga (~1.4mm).

• Wire Material: Typically high-carbon steel for strength and resilience. Can be finished with powder

• coating or electrogalvanizing to prevent rust.

2. Spring Specifications

• Spring Height: The height of an individual coil.

  • Common Heights: 5", 6", 7", 8". A 10-inch Bonnell coil is less common but possible.

  • Taller springs can feel softer and are used in thicker mattresses.

• Coil Count: The total number of springs in the unit.

  • A Queen size (60"x80") typically has between 250 - 350 Bonnell coils.

  • Higher coil count generally provides more precise support and a firmer feel, but the wire gauge is a

  • more significant factor.

• Tempering (Heat Treatment): Springs can be heat-tempered to increase durability and prevent sagging.

• This is a standard but essential process for quality.

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