Note that an un-heatreated piece of 4140 will be both harder & stronger than a piece of 1018. The 4140 has even far greater potential through proper heat-treating & tempering. I don't really recall the hardnes/Temper range for it, but seriously doubt a piece heated to over 1200°F will retain a hardness of Rockwell 40C. That it is strong enough for the mentioned uses is obvious for a piece of case-hardened 1018 was adequately strong. That 4140 will work for these conditions is simply testimony to its great versatility, but I can tell you for certain if Faux Colored parts were its major use it would be an extremely short time before it would be no-existent as an available alloy. Its greatest use is for high strength, heat-treated parts which does not include tempering it to 1200+°F.
