An employee was splitting a bundle of 60-pound rail for an overhead bridge crane. After the banding straps were cut, a wedge and pry bar were used to separate the rail that was on its side. The employee then used an adjustable wrench on the foot of the rail to tip the rail over into an upright position so a beam clamp could be attached for lifting rail. The wrench slipped off the foot of the rail and the rail tipped back down pinching the employee's right index finger against dunnage on the ground. The fingertip was amputated.