3 replies to this topic

[daraj]

Hi, often encounter situations where one material of construction is chosen over another in the later stages of a process design. Often the estimates cost has to be adjusted because of this and sometimes the tools we use for this do not really have all materials of contruction.

 

Iam looking for latest refernce(atleast within last 5 years) where relative costs of engineering materials(expressed as cost perunit weight) are given usually with cabon steel as base(i.e assigned index value of 1, and others are expressed as a ratio over this).

US basis would be OK. If you do not have an online link but know a book or two please let me know, although I would prefere a reliable online link for quick reference. type of materials for which I need such costs are as follows:

stainless steels(304, 316 etc.)

titanium

tantalum

duplex

inconel

hastelloy

aluminium

alloy 20

carpenter 20

 

Thanks

 

[daraj]

Hi, if you have any references please share, thanks

[Art Montemayor]

Daraj:

 

You have to resort to common sense to have a firm idea of what are the absolute and relative costs of materials of construction.  This should have been thoroughly discussed in university.

 

The local cost of such materials depends largely on many factors (most of which are out of your control):

• Where you are located;
• Whether your country practices Free Trade or not;
• Whether your country manufactures the materials;
• Global economic conditions;
• Global political conditions;
• Quantity (or “demand”) of materials that your country consumes yearly;
• Fluctuation of your local currency;
• And many other factors also play a role.

As you should know, even the price of gold varies, from day-to-day.  So the prices you collect in a database are attached to so many considerations that the relationship you are trying to establish is not really there.  If you want to estimate prices of materials, go to a professional who does it all day.  These persons are usually found in large engineering companies.  They are the experts – and even they will tell you that their estimates are subject to approximately 20-25% error (minimum).

 

 

 

[daraj]

Hi Art, thanks, Iam not really looking at really accurate estimates of absolute costs. But there should be refernces out there that give relative costs or cost ratios, which do not generally change a whole lot during a year or even across 2-4 years.For instaNce, ratio of ss304 to SS316 has not changed a whole lot in the past years. I have a refernce which gives ratio of costs with an index value of 1 assigned to carnon steel but that reference is old. Iam looking for any references(handbook or textbook or open literature) that can give these ratios from the last 5 years or so or more recent

thanks

 

as an example, something like this

http://f3.tiera.ru/S...ng 5e/app-c.pdf

 

but only more recent