A method of manufacturing a helical bar concave from a flat, rolled laser cut arrangement that provides a net helical concave functionality. Laser cutting a flat metal sheet to form helical cutouts defining a percent open area having a helical geometry in combination with configurable rub bars mounted in a helical fashion results in a configurable helical bar concave in which the number or aggressiveness of the threshing surface on the inside radius of the grate may be changed and/or the rub bars may be moved to the outside of the grate to change the percent open area and hence the separation characteristics of the concave.