No real help to me as I have no clue as to what parameter your trying to apply the word soft to. The only soft vs hard reference I refer to is as one would judge its number on the Rockwell hardness scale. As in diamond "hard" gold "soft". Stainless steel is harder and more brittle than any of the other common steel fasteners. And adding a strength rating related to hardness is not related at all, their two totally different subjects. You do come up with some really off the wall statements sometimes though, I just hate to see some of your erroneous statements taken as gospel by some of the less knowledgeable members of the forum, as in the case of "Soft" stainless. Try drilling the heads off of a few 1/4" bolts, two stainless and two grade 5 steel, and you will see which is harder. As a rule when you see the addition of chromium added to an alloy in the percentages present in stainless you will automatically know it going to be very hard and brittle, when you see the addition of carbon added to an alloy you know the higher the percentage the softer it will be. Kinda like knife blades, high carbon steel blade is quick and easy to put a good edge on but due to softness will not last long, stainless blade is very hard to get good edge on but edge will last much longer. Hope this helps you..
Hey Ray -
That stainless steel screws are of a harder or stronger metal is a common misconception (among laymen)– we've heard it before. Thanks for confirming it. Hopefully that misconception has now ended here for anyone who might previously have held it.
It's interesting to note that, similar to fasteners, in testing, stainless steel anchors have been shown to be inferior in strength (shank bending- Practical Sailor) to their identical regular steel counterparts, because in those cases they were made to identical dimensions, when they should have been designed with increased dimensions and thickness in weak areas to compensate for the strength loss. If stainless were in fact stronger why would it be necessary to increase its thickness in these areas? Answer: because it's not stronger.
BTW – drilling, or “drillability” , is not an acceptable way to judge the hardness of a material. Have you ever tried drilling a deep hole in copper, for example? I have many times- it's a very difficult task, and yet copper is a soft material. The alloying elements are among a host of many other properties besides hardness that confound the determination of hardness, rendering such an unscientific pronouncement highly questionable.
I was pretty clear in stating that tensile and yield strength were my criteria for the judgement- mostly because the figures for these properties are available for any layman to understand and confirm in published data. Check it for yourself.
I must say I've never heard anyone say that regular steel high carbon steel knife blades are softer than stainless steel knife blades. Why? Quite simply, because it's not true. In the science of alloying, carbon content, and heat treatment of cutting edges, and as Ixneigh has found, the opposite is more frequently the case. Though technology is reducing (in some exotic cases reversing) the difference, stainless steel knives are a compromize of performance.
Contrary to your statement, carbon in steel is the element that is mostly responsible for its becoming hard (and not soft) during the heat treatment process, within limits, the higher the percentage of carbon present the harder it can be made. Basic metallurgy, that. Yet another misconception (that's three) with no basis in reality. However, don't underestimate the ability of other forum members to figure things out for themselves, I have found they are quite capable.
It might be possible (?) to find a high quality stainless steel knife material that takes an edge better than a low quality high carbon steel blade, but that would be the exception. I prefer to, and will continue to, confine my opinions to be within the realm of fact-based science. I would suggest you do the same – we would agree on a lot more things!
It's a good idea to consult a search engine for a trusted source if in doubt, though. Here's one knife site (among many, pick any) regarding the compromize...
http://zknives.com/knives/kitchen/misc/ ... vscs.shtml
I quote from the author (a knife expert) halfway down the page...
“ Basically, to me Stainless vs. non-Stainless translates into easy maintenance vs. performance argument. Overall, for most of the non-exotic alloys, stainless steels are lesser performers compared to carbon counterparts, given similar composition, proper edge and equal cutting medium. However, if you have quality stainless steel, properly heat treated it is more than enough for the kitchen needs for majority of home users out there. If you strive for maximum performance then non-stainless, high Carbon steels are the way to go.”
The overriding message from my posts is that it's important to be aware that substituting stainless steel for regular or carbon steel in fasteners and other applications is trading shininess and corrosion resistance for diminished returns in other properties. Things can be more complicated than they appear at first. Stainless steel is not a panacea, it's a compromise.
Hope everybody's entertained – 'cause science can be fun – B.
“Arithmetic is not an opinion” - Old Italian Proverb.