An air bag module (10) includes an axially elongated, extruded housing (20) having a nautilus-shaped profile defined by a single continuously extending spiral-shaped wall (23). The spiral-shaped wall (23) has first and second free ends (27, 28) and the spiral-shaped wall (23) has a generally continually increasing radius of curvature from the first end (27) to the second end (28). The housing (20) preferably has a decreased radius portion (25) for holding an inflator (80) therein and an increased radius portion (26) for holding an air bag (40) therein. The decreased radius portion (25) has a radius of curvature which is less than a radius of curvature of the increased radius portion (26).
