Replacement 1/2-Inch Keyless Chuck with SDS Adaptor - 20 UNF Thread

For chuck removal, open chuck jaws completely and remove lock screw (TORX or Phillips head) by turning CLOCKWISE (may be quite tight). Place the short end of an L-type hex (Allen) wrench in the jaws and close tightly. Using the long end as a lever, turn COUNTER-CLOCKWISE to loosen chuck. If chuck is too tight, hold drill securely and tap wrench with mallet - again, remembering to apply force to turn counter-clockwise. Follow opposite steps to attach new chuck.