Stainless steel type 316 and type 304 are raw material grades for stainless steel. Stainless steel fasteners are sometimes referred to and ordered as their raw material grades (such as SS 316 and SS304) and sometimes referred to and ordered as their ASTM specification. The common ASTM specifications that cover stainless steel bolts are A193, A320 and F593. Type 316 stainless has a unique chemical composition which includes 16% chromium, 10% nickel and 2% molybdenum. Type 304 stainless has 18% chromium, 8% nickel and no molybdenum (this is where the “18-8” designation comes from). Stainless steel 316 is more resistant to chlorides than stainless steel 304, making it the preferred material for marine construction.
Sometimes, a type “SS316L” or type “SS304L” bolt will be specified in a particular application. The “L” at the end of these designations refers to the low carbon content of the steel. Stainless steel certified to 316L or 304L will have a maximum of 0.03% carbon, versus the 0.08% maximum that regular 316 and 304 can have. Low-carbon stainless steel bolts are used to avoid corrosion problems that are caused by welding, as the lower carbon content reduces the “sensitization effect” (the precipitation of chromium carbides at grain boundaries) caused by the high temperatures involved in welding. Since carbon is the principal hardening element in steel, low-carbon bolts have reduced hardness but are easier to weld.
The difference in carbon content does not affect the overall corrosion resistance of the steel, and low-carbon stainless steel bolts can be ordered to each of the A193, A320 and F593 specifications. When you order a low-carbon stainless steel bolt, just let us know about this requirement and our expert estimators will be sure to provide you with the correct material.
Pressure Handling Capacity of SS 304 , SS316 & SS316L in bar or psi ?
@Abhishek – I am sorry, but we do not have that information. Apologies.
What is the maximum carbon in ss316
@George – For SS316 the max carbon is 0.08%. For SS316L it is 0.03%.
Generally bolts are not welded, if so why is 316L Bolts manufactured. is there any advantage over using SS 316L Bolts.
@Shyju – We don’t have any engineers on staff, so I cannot speak to all the possible advantages or disadvantages of SS316L vs SS316 material in various applications.
Hi everyone,
I am looking for a stainless steel that is easily turned, optically “looks” the same as SS316L, but more reasonably priced than SS316L. Any suggestions?
For the lower price I am willing to trade off some Corrosion resistance properties. Price and corrosion resistance of SS304 is well suited for my purpose, however SS304 has a yellowish color which does not suit the application.
Thanks in advannce for your inputs!!
@Deepak – Thank you for your inquiry, but we do not have any suggestions. Apologies.
dear sir
in orifice meters .which material is recommended to manufacture the orifice plate ss304 or ss316.
the product is dry gas.
operating pressure:21-70 bar.
flow rate:15mmscfd