Where do you get your Material Properties from? 4

[yacpro13]

Hello,
I have a very simple question: where do you get your material properties from, either for hand calcs or FEA?
So far, I've been using a combination of textbooks, Machinery Handbook and Matweb.

I would like to buy a single authoritative book for all the times I need a material property. I like Matweb, but I find it is a bit too detailed. For example, a search for AISI 4140 brings up 33 materials with different raw material size (1 inch, 2, 3, etc), and different quenching / tempering temperatures. On our manufacturing drawings, we do not specify the tempepratures of the heat treatment - we leave that up to the heat treatment specialist. What we specify is the hardness needed - whether the hardness is for wear resistance or a result of the increased yield strength needed.

Any recommendations for a good reference for material properties would be very appreciated.

 

[boyze]

assuming you are referring to basic properties like mu, E, G, alpha, conductivity, ....

in rough order of preference (the top 5 generally have the same credibility and many times have the same base source):
- company official database (if they have one: the 3 large companies I've worked for had one and my own company also has one.)
- Mil-Hnbk/ASME/ASCE/SAE/.....
- supplier datasheets
- reputable textbooks/handbooks (most give their sources)
- FEA program databases
- matweb
- open web but vetted

if for an uncommon and/or unique material then "test" would be on the list

if looking for properties like Fty, Ftu, endurance limit, high and/or low temp properties, .... then sources become limited and even the ones found have to vetted with caution

Have Fun!

James A. Pike

http://www.xl4sim.com

http://www.erieztechnologies.com

 

[fegenbush]

For the chemical composition of 4140, see ASTM A322. For mechanical properties related to the diameter and hardness, see ASTM A400. You will have to work backwards, since A400 is intended to be used to make the material selection.

 

[GregLocock]

James' list is good, also the supplier of the material itself, for instance with rubber or brake pads where it is cooked up by witches in cauldrons.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?

 

[tbuelna]

...I have a very simple question: where do you get your material properties from....

Unfortunately, your question is not so simple. Rather it is quite complicated. Most commonly, the material property standards required for analysis work are defined in a contract statement of work or design requirements document. In the US aerospace business AR-MMPDS-01 is the most widely accepted standard for metallic material properties. But when it comes to a more complex analysis that must consider factors such as fatigue or fracture, even the data provided in AR-MMPDS-01 is often not sufficient.

Factors such as quality control of your manufacturing processes can have a big effect on material properties in your finished product. And these factors must be taken into account in your analysis work.

Best regards,
Terry

 

[TGS4]

I agree with tbuelna. It all depends on your purpose. Are you looking at design by analysis, in which case you may need minimum-specified material properties. Or are you performing a fitness-for-service on an existing part, in which case you may need actual as-manufactured properties.

Is there an industry standard for your industry?

 

[yacpro13]

Tbuelna - your response is very sound, and I cound't agree more.
I realize that this 'simple' question is actually quite complex for some industries, like aeropsace.

Let me elaborate a little more on the purpose of this data: We design custom industrial machines. We specialize in production automation, however, we also do purely mechanical systems such as hoist systems, for example.

There is no material properties standard for our industry. Material properties are used for hand calculations and/or FEA, always in a design-by-analysis environment, never fitness-for-service. We only deal with linear analysis, and parts are always used at room temperature (or very close to RT).

With this in mind, I was looking for an authoritative, complete source for properties of common materials (6061, 5052, 4041, 4340, 1020, 304 etc etc).
When relevant, properties of materials with various heat treatments would be useful.

In my search, I found eFunda (link below), which appears to be exactly what I was looking for:

http://www.efunda.com/materials/materials_home/materials.cfm

 

[fegenbush]

yacpro13,

There are materials properties standards for every industry. That is because the materials properties standards do not limit the industry in which they are to be used.

You specify a material, say 6061 Aluminum, there are standards for how that material is produced, it's chemical composition, mechanical properties, etc. What you require are the ASTM material standards which specify the minimum chemical and mechanical properties.

It is not acceptable to use actual testing to determine the material properties since these are subject to change based on heat/lot, manufacturer, phase of the moon, etc. However, the published minimums still apply.

 

[btrueblood]

"It is not acceptable to use actual testing to determine the material properties"

I love blanket statements like that. In the real world, where materials are subject to a variety of post-mill processing techniques that can affect their properties, it is fairly common to conduct limited (small sample size) testing to determine the strength/hardness/factor of goodness/whatever of the final product. Such testing can be used to verify a lot meets a minimum condition (like proof testing of a lot of fasteners), or might be used to sort the end items (grades of thermistors or RTD temperature sensors). Often, those limits get determined by a fairly small sample of material during the prototyping phase. Knowing how to conduct a valid test, and when to do it, is what keeps Materials & Process engineers employed.

 

[fegenbush]

btrueblood,

You are correct. My intention was to prevent the following scenario:

<The product fails>
Engineering: "I don't understand. We tested one piece of material from manufacturer X 10 years ago and used that data to determine our allowable stresses for FEA. Does it matter that the material for the part that failed was produced 10 years later by a different manufacturer?"

To clarify, proper lot/heat based sampling and statistical analysis can be used to determine allowable stresses. However, this is a continuous process and must be maintained throughout the production life of the part to ensure raw material quality meets the criteria on which the design is based.

 

[dhengr]

Yacpro13:
Take a look at “Metals Handbook,” from ASM (American Society for Metals), it has a real wealth of general info. on various metals. Look at the ASTM stds. for any material of interest. Go directly to the material manufacturer for info. on their material. None of these are simple, this is not a simple matter. You have to order your materials to some recognized industry standards such as ASTM, and these include min. mechanical properties, etc. which you use for your design. These are industry stds. which pertain to the material, its manufacture, etc., and you adopt them as part of your stds. In your order paper work ask for mill certs. on that lot of material, or any other testing which is critical to your design. These are your final control on the material you are receiving, and you may run some in-house tests to confirm some of the cert. results. These certs., etc. come directly from the material manufacturer, so they warrant them. You may pay a premium for this mill cert. paperwork or any special testing, particularly on small lots from steel supply house, but they can usually dig this up, as part of their own material control system. Otherwise, they are furnishing a generic piece of material which they claim and guarantee meets the spec. you ordered to, and their credibility is your fall-back as to materials you received. I’m a little surprised that you claim to be designing and building this type of equipment, and are still asking this question, this way.
Good Luck

 

[geesamand]

My company uses the ASME Section IX boiler code material tables.

It's pretty conservative but it covers a wide range of ductile materials including temperature range, with applicability to static or quasi-static loading.

David

 

[tbuelna]

yacpro13-

In the US commercial sector the most common source for material and process standards is ASTM. But as many others pointed out, the material properties given in these standards are based on the material being manufactured and processed with a certain level of quality control. And unless you can validate that the material was manufactured and processed according to the prescribed QA requirements, then you have no way of knowing if the material properties in your finished product will be the same as those used for your analysis.

As a professional engineer, you should be ready to stand behind the results of your analysis work. This would include being able to justify the legitimacy of the material properties used in your analysis. Most anyone involved in a CDR/PDR would accept material properties sourced from an ASTM/AMS standard or MMPDS-01, but they would laugh-out-loud if you told them MatWeb.com was your source for material properties.

Good luck to you.
Terry

 

[yacpro13]

@dhengr & @ Terry - my question was especially pertaining to material properties to be used in the design phase. As mentioned above, at this time, I may use MatWeb very early on in the design phase to get a rough idea of some material properties. I find this website useful, however, like Terry mentioned, MatWeb should not be used as the souce for material properties for final validation of design.
As mentioned above, this is why I am currently using Textbooks to get trusted minimum values for material properties for design by analysis.
With the designed finalized and the meterials specified for all parts, manufacturing orders the raw material, which is received with Mill Test Reports.

Even though I trust the McGraw-Hill textbook I use, I wanted to purchase a reference book specialized on the topic, which is what lead me to ask here.

I will take a closer look at the ASM Metals Handbook - seems like exactly what I was looking for.