 This is the last No.2 drill that used the two-jaw springless chuck patented on August 14, 1877. The jaws each had a V groove in the middle, but the opening between the jaw guides only permitted 1/4 inch bit shanks to be gripped. The minimum bit size was about 1/16th inch, not a very wide range compared to later three-jaw chucks the same outside diameter. This jaw design was also prone to losing the jaws, distorting the chuck shell, or breaking jaws because they hang out too far in order to grip the smallest bits in the range. |