chemical composition and formula for common steel screws

[unknown]

I would like to know the composition and chemical formula for the average steel screw. I teach an Earth Science class and would like general information or a lead as to where I might find this basic information.

 

[thaidavid]

Unknown,

Try this link, maybe it will help.

http://www.industrial-fasteners.org/rawmat/index.html

David

 

[Nick6349]

I could throw one on the arc and spark tomorrow for ya, I'll post the results and see if I can determine the aisi steel designation.


Nick

 

[volvoboy]

Does anyone out there know the tolerence of the materials that makes up 316 SS? (example: Carbon: 0.08 wt. pct +/- x%)


Mike Mulhern

 

[kenvlach]

MatWeb is the easy way to find out the composition of almost any material, but their site takes a bit of navigation. For stainless steel, it's easier than most other materials. Go to

http://www.matweb.com/index.asp?ckck=1

On the Searches line, click on Material Type,
then just click on 'Find' next to the Stainless Steel listing under the Ferrous Metals heading.
Next, scroll down the list of stainless steels until you reach 316 [note: Not 316L, which is a low-carbon grade, nor any other suffix]
(have to use 'Next Page' once).
Click on one of the 316 entries and voila, composition, etc.

Component Wt. %
C 0.08
Cr 17
Fe 65
Mn 2
Mo 2.5
Ni 12
P 0.045
S 0.03
Si 1

Note: these are average compositions for alloying elements and limit values for impurity elements. A more specific source for stainless steels, like Carpenter Technology, will specify the allowable ranges or limit for each element:
"Type 316 Stainless
(UNS S31600)

Single Figures are Maximums
0.08 C, 2.00 Mn, 0.045 P, 0.030 S, 1.00 Si, 16.00-18.00 Cr, 10.00-14.00 Ni, 2.00-3.00 Mo, Bal. Fe [wt. %]

Type 316 stainless is a molybdenum-bearing austenitic stainless which offers better corrosion resistance in chlorides and many other environments than Type 304. It also has higher tensile and creep strength at elevated temperatures than the conventional 18% chromium - 8% nickel alloys."

http://www.cartech.com/products/index.html