This holder is best used for holding morse taper tools. It can be used for drilling, boring, or reaming operations. Fits industry standard tool posts. High tensile strength chromium molybdenum alloy steel. Thru hardened, ion-nitrided, and black oxide coated. CNC precision ground and qualified for accuracy and super precise tool change repeatability within 0.0001". Applicable for deep drilling applications, heavy duty drilling applications, reaming and tapping.