When sourcing mattress springs, the wire gauge (thickness) is the most critical factor; a lower gauge (e.g., 12-13) indicates a firmer feel and higher durability, while a higher gauge (e.g., 14-15) offers more flexibility. You must also specify the coil count and turn count (the number of revolutions in a single spring), as these directly impact the supportive integrity and longevity of the mattress. For high-end applications, prioritize high-carbon steel with heat-treatment processing to ensure the springs maintain their shape and resist sagging over time.