O-1 tool steel holds an edge much better at lower angles, 25° or less. This makes these chisels much more useful for paring or slicing tasks, where a more acute cutting angle works best. Lie-Nielsen produce five sizes in O-1 tool steel, each ground at 25°. They are available as a set or individually. The sizes are 3.2mm, 6.3mm, 9.5mm, 12.7mm and 19mm. They are forged in the traditional socket style for strength and fitted with polished Hornbeam handles. The sides are square and parallel with thin edges to give maximum access. The backs are ground flat and hand finished. Overall length: 230mm(9"), blade length 85mm(3.3/8").