The following letter codes are used in the fourth digit position to indicate additional design features. A 116 is a steel tooth friction bearing bit designed for a slightly softer formation than a 216. A 537 is a carbide bit with friction bearing and carbide inserts on the cutter heels. It is designed for a slightly harder formation than a 527. BBI coding distinguishes differences between rerun waterwell and oilfield quality drill bits.
Bits are in like new condition.
They do have a few hours of use with very little gauge wear. Wear is indicated by slight gauge wear, slightly weak seals and slightly worn buttons. New drill bits which for whatever reason were never run in the hole. Generally acquired through liquidations, overruns, fire sales, etc.