SizeBore Range ØdØD MmL mmPart No. Example ER-11 1 to 7 mm in steps of 0.5mm 11.5 18.0 ER11 5mm ER-16 2 to 10 mm in steps of 1mm 17 27.5 ER16 8mm ER-20 2 to 13 mm in steps of 1mm 21 31.5 ER20 8mm ER-25 2 to 16 mm in steps of 1mm 26 34.5 ER25 8mm ER-32 3 to 20 mm in steps of 1mm ¼” to ¾” in steps of 1/16” 33 40.0 ER32 8mm ER-40 4 to 32 mm in steps of 1mm ¼” to 1” in steps of 1/16” 41 46.0 ER40 8mm