Our hand reamer is made from high grade high speed steel.Its tolerance is based on H7.Metric size also available. Fractional Size (in. )Decimal Equiv. (in. )Length Overall (in. )Length Of Flute (in. ) 1/80.12531-1/2 9/640.14063-1/41-5/8 5/320.15623-1/41-5/8 11/640.17193-1/21-3/4 3/160.18753-1/21-3/413/640.20313-3/41-7/8 7/320.21883-3/41-7/815/640.234442 1/40.254217/640.26564-1/42-1/8 9/320.28124-1/42-1/819/640.29694-1/22-1/4 5/160.31254-1/22-1/421/640.32814-3/42-3/8 11/320.34384-3/42-3/823/640.359452-1/2 3/80.37552-1/225/640.39065-1/42-5/813/320.40625-1/42-5/827/640.42195-1/22-3/4 7/160.43755-1/22-3/429/640.45315-3/42-7/815/320.46885-3/42-7/831/640.484463 1/20.563