The Spring lock roller blind system has been developed to provide excellent performance over a wide range of window blind sizes, fabric weights and thickness. The manufacturing process does not involve the use of glues or sewing and produces a clean and professional finish.The two systems are designed for increasingly larger and heavier Blinds, particularly suited to commercial projects. The diameters of the sprockets for the control chains increase to enable the larger blinds to be operated with minimum physical effort. Spring lock roller tubes and metal bottom bars are designed with patented fabric fixing slots of varying widths. This manufacturing process ensures that the fabric will remain firmly attached to the roller and will not become detached in normal use. The varying widths of the slots allow fabrics of various thickness to be accommodated. The same fabric location method is used for fixing the fabric to the bottom bar eliminating the possibility of loose fabric, producing a clean and professional finish to the blind.