(f) «Knife» means any dagger, dirk, knife, or stiletto with a blade over three and one - half inches in length, or any other dangerous instrument capable of inflicting cutting, stabbing, or tearing wounds, but does not include a hunting or fishing knife carried for sports use. (law.stackexchange.com)
Whether or not a literal knife with a blade under 3.5 inches long constitutes a redefined knife, it certainly constitutes a «dangerous instrument capable of inflicting cutting, stabbing, or tearing wounds». (law.stackexchange.com)
All that crime requires is intent to injure and actual injury, regardless of the seriousness of the injury, resulting from use of a dangerous instrument (the dolly qualifies). (sbnation.com)