EE maintenance Worker for KCT, on 04/22/2013 at approximately 2:00 pm, was reconditioning roller frames on a 226 D9R Dozer. EE was driving the equilibrium bar pin out, and as it was 1/4 inch from being out, ee placed a bolt in it, and was holding onto the bolt when the equilibrium pin came out and the roller frame fell and pinched ee left thumb.