One of my friends had about 60' of 057 , 3/8 semi-chisel (Oregon 73) . He gave up trying to use it, so he gave it to me as a swap for repairs. Well, lo and behold, I found a use for it. Whenever a used 050 bar comes in, I check how wide the groove is, and about half of them will accept the 057 without a hitch when I get though cleaning out the groove with a solvent.