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One of the very important numbers on gun barrel steel strength is on two scales Izode and Sharpy, one uses a V notch and the other a U notch in the test material for hoop stress strength. The report said that for comparison a good grade of gun steel would have a number of 42 for this important strength factor and 12L14 has something like a 5 on this scale . The colder the temperature the lower this strength factor degrades.
Over all hoop stress is what we are mostly concerned with in this case which takes into account brittleness, inclusions and seams. Steel can still have impressive tension and compression numbers if no shock load is present, which is the case with 12L14. By the way the digits in 12 L 14 stand for , 1 means carbon steel, 2 means re-sulferized and re-phosphotized , L mean lead and 14 mean the percent in hundreds of the chief alloying agent which in this case is carbon. That is 14-one hundreds of one percent , .14 percent.
By comaparison 1137 and 4140 are a good deal harder but also are not brittle. We often associate hardness with brittleness but this is not necessarily true and is the reason tempering metal is so important.
Over all hoop stress is what we are mostly concerned with in this case which takes into account brittleness, inclusions and seams. Steel can still have impressive tension and compression numbers if no shock load is present, which is the case with 12L14. By the way the digits in 12 L 14 stand for , 1 means carbon steel, 2 means re-sulferized and re-phosphotized , L mean lead and 14 mean the percent in hundreds of the chief alloying agent which in this case is carbon. That is 14-one hundreds of one percent , .14 percent.
By comaparison 1137 and 4140 are a good deal harder but also are not brittle. We often associate hardness with brittleness but this is not necessarily true and is the reason tempering metal is so important.