An improved method of cutting a helical gear sector onto a pivoting arm of a casement window is disclosed. The method includes beginning with a pre-hardened flat sheet of steel stock and cutting the arm and the helical gear sector of the arm in two steps. The non-toothed portions of the arm are cut with a laser and nitrogen assist or shielding gas to prevent any oxidation to the non-toothed portions of the structure. The helical gear sector is also cut with a laser, but using oxygen assist gas. Use of the oxygen prevents recasts slag from accumulating in the gear sector. Thus, a finished part is completed with two laser cutting operations thereby eliminating the need for separate stamping, shaping, deburring and subsequent heat treatment processes used in conventional manufacturing methods. The subsequent heat treating is eliminated because a pre-hardened steel stock may be utilized.