Black pipe from Turkey that's used for gas line pipe in RV's & travel trailers is the same when you're trying to cut threads in it. Pipe fittings from Malaysia are loaded with pin holes in them.
Most likely all the impurities we had some channel here one time that would cut very hard it had automotive glass embedded in the iron most likely from a poor smelting job. that was Canadian channel made from junk cars from the good old U.S.A.
