Morse Taper drill sleeves are used as reduction or sizing up of Morse taper tooling. Most common Morse taper tooling is taper shank drills, also Morse taper reamers and other HSS cutting tools.
The Morse taper drill sleeves are hardened steel, internally and externally ground. Size adaptors from one size stepping up to the next or skipping to a couple larger sizes (ie; 2- MT sleeve); this allows a No.2 Morse taper drill to be sleeved to suit a No.3 Morse taper machine spindle. Quite often several drill sleeves are joined together to gain the required Morse taper.
Morse tapers range from No.0 Morse taper up to No.7 Morse taper. No.3 is the most popular; drills aprox. 23mm thru to 32mm. Most bench drill presses are either No.2 or No.3 Morse taper spindles.