The ISO 30 is a tapered tool holder and is very common in smaller cnc machines. The Taper is 7:24 and there is a pull stud used by spindles to draw the chuck tighter into the machine spindle We offer the ISO 30 tool holder in two collet styles: ER32 and ER40. ER 32 tool holders have a shank capacity of up to 3/4" or 20mm. ER 40 and SYOZ25 tool holders have a shank capacity of 1" or 25mm. All toolholders are sold with a pull stud for as HSD spindle and a ball bearing collet nut that facilitates both RH and LH rotation. Holders are balanced to 24,000 RPM at G2.5