S2kRally

I know this sounds like a weird question, but Im looking for some numerical data on comparing mild steel, to stainless steel tensile strengths. This is for a project Im doing. I did the typical google search and everything I found is useless or I cannot decipher what is being shown. Does anyone know anything about the tensile strength of each material?

ScottyBallistic

Problem is you need to know what grade of each you want to compare. I am know expert But I know a little from Working at Northstar steel as far as grades go .

boltonblue

wiki??

they have some data on ultimate yeild strength in mega pascals.

looks like stainless is ~2x mild steel. which is about half of heat treated.
but without understanding the dynamics of your particular needs, they are just abstract numbers.
of course i'm an EE not an ME.

jbird0007

hmm if i was at work I'd let you know. I have a few engineering books that would have that in it, as well as solidworks has about fifty different types of steel programmed in with density, tensile strength info, etc. ill post on monday if you still dont have an answer

CTMechE

Most steel is known by the spec or standard it's made to, so you'd need more information to start with besides "mild steel" or "stainless steel" as there are literally several thousands of varieties of each, and their properties can vary significantly based on alloy content and heat treatments. If you have specific metals, I can probably pull up specs for you.

CTMechE

You don't want ultimate strength, as that means breakage point, which is beyond the deformation point. Yield strength is the point where the metal begins to deform, but not yet break. Unless his project is a one-time-use thing, it should be regular tensile strength he's looking for.

boltonblue

knew I should have taken that materials course.

S2kRally

Thanks for all the comments guys! Im unsure as to the exact metal but I believe im trying to compare either 304 or 316/316L stainless steel. I hope the properties are somewhat similar, as I dont know that ill be able to truly find out exactly which material it is.

I guess the answer I needed wasnt that in depth anyways. The fact that most stainless steels are "around" twice as strong regarding tensile strength compared to untreated mild steels is really as best of an answer as I need. Im just looking for verification that stainless steel bolts and studs carry a higher tensile strength than their mild steel counterparts. Im going to be replacing all my engine hardware on my Supra's build with stainless steel components, I wanted to make sure I was taking a step in the right direction. I also have another project im working on regarding the same subject.

CTMechE

Yeah, you should have no problem, then. There are also fastener grades for nuts & bolts (Grade 5 and Grade 8 are common, Grade 8 is stronger) that might be an easy means of identification.

ScottyBallistic

Metric bolts will have different grade ratings than Standard ..

Also be carefull what you use the Stainless hardware on. Stainless will gaul and weld it self together that your only choice is to break the bolt to get it off. So don't use Stainless bolts with Stainless nuts.

What I do is use a little never seize on stainless hardware. Also Stainless is softer than Mild steel. So it will stretch before it snaps so not good for something that requires TQ to yield. Guess it depends what you want to use the hardware for Valve covers accessory's will be fine, Don't use it on anything internal of the motor.