its a bosch electric hammer drill model # 0 601 194 639

bob, January 2009

if you need to remove the chuck completely the correct way as specified in service manuals is to open chuck to full capacity, undo screw in back of chuck mouth (left hand thread) tighten chuck onto short arm of 12mm allen key, and with a sharp blow from a metal or dead blow mallet the chuck should unscrew. if not soak some gt85 or simaler oil and try again tomorrow, or contact me rugjnkn@aol.com

Jenkin Repair Services, January 2009

This is just a regular Bosch Hammer Drill with a 1/2" capacity chuck. You should have a chuck key and just use it to open and close the chuck. It isn't stuck is it?

Tony-www.toolsandmachinery.com, January 2009