OTC's Safety Wire Drill Guide Set is the perfect way to drill nuts and bolts for use with safety wire without breaking the drill bit. These heavy duty, plated metal guide blocks guide, align, and support the hex head or bolt threads for a perfectly centered, square, wire hole. The hex fixture fits nuts and bolt heads that measure up to 1-1/4 inches. The SAE guide bar is threaded for 1/4-20, 5/16-18, 5/16-24, 3/8-18, 3/8-24, and 7/16-14 bolts. The metric fixture bar covers M6x1.0, M8x1.0, M8x1.25, M10x1.25, M10x1.5, and M12x1.5 sizes. Value is at the core of the OTC tool and equipment portfolio. For a simple repair or the most complex drivability concern, these award-winning tools universally solve problems faster, and at better value, than any other product line available. Whether it's a specialty tool or unique piece of service equipment, OTC provides top solutions to modern automotive service challenges while increasing technicians' productivity and shop profits.