A-1 Security Mfg.'s compact, accurate and portable HG1-605C carbide cutter for 137 Standard, 137A & 137S tubular key blanks can handle brass, plated brass or plated steel blanks with ease. Tip: The HG1 is designed to cut keys leaving a wall thickness of .004 —.008. Iif your machine is leaving more than .008 or the cutter feels like it is rubbing, it could be a sign of a dull cutter. Consider purchasing the HG1-605C as your replacement cutter.