Semi Finished Nut

I think a semi-finished nut is chamfered on one side, a finished nut is chamfered on both sides and an unfinished nut is not chamfered at all.

Semi-finished essentially means what it says. It is a description that started in the structural bolting end of the business and has been carried over to other areas. Other than the dimensions required by the appropriate standard, generally ANSI 18.2, the only part machined is the threads and bearing surface with other surfaces being machined at the mill or purchaser's discretion's. The nut is generally made with lesser tolerances.

Key point it is cheaper and will do the job.