Designed for high restoring force combined with low starting force for centralizing the casing pipe in vertical, deviated and horizontal wells. High performance characteristics are combined with easy field assembly Bow springs are of high quality alloy steel, hot bent to shape using dies and then heat treated under controlled temp / time cycles for consistent spring characteristics. Collars are of widened design for greater frame strength and to prevent bows hitting casing. Integral hinges are designed to wrap to the inside and are with eight sections and seven shear points for minimum disorientation even under severe stress. Hinge locking pins are of high strength steel for maximum structural strength. They are available in 4 ½ ” to 20 ” sizes.