The Open Coil (Bonnell) Spring is the classic spring unit, and has, through the years, proven its worth. It is made from around hourglass shaped coils which are interlinked with spiral wire to form a spring unit structure.
Springs have to be made of “SPRING STEEL” or “TEMPERED SPRING” not with mild steel. Spring steel springs/ Tempered springs cannot be crushed by a mere humans weight and because of their springing capability they respond gently to different human weights. Our springs are produced in EUROPE and imported in already compressed form with tons of force and opened up here.