I have seen some statements in searches here, that made me want to re-familiarize myself with stuff that I used to know but haven't used and have long ago forgotten. (Braincells......
)
At first I was gonna just post a question, asking the differences in stainless for what we are interested in, but instead, I just Googled and found out some info so here are easy links for your own info.
Basically, there seems to be two popular main types, 304 (also called 18-8 due to the chromium/nickel content) and 316.
http://www.machinist-materials.com/stainless_table.htm
http://www.machinist-materials.com/stainless_table_two.htm
From this page:
http://www.matweb.com/search/SpecificMaterial.asp?bassnum=MQ304A
Applications: beer kegs, bellows, chemical equipment, coal hopper linings, cooking equipment, cooling coils, cryogenic vessels, dairy equipment, evaporators, flatware utensils, feedwater tubing, flexible metal hose, food processing equipment, hospital surgical equipment, hypodermic needles, kitchen sinks, marine equipment and fasteners, nuclear vessels, oil well filter screens, refrigeration equipment, paper industry, pots and pans, pressure vessels, sanitary fittings, valves, shipping drums, spinning, still tubes, textile dyeing equipment, tubing.
From Sabco:
http://www.kegs.com/factsaboutkegs.html
"1) Kegs are made from fine, food-grade 304 stainless steel."
I have found some references to Stress Corrosion Cracking, caused by several things namely
"(2) residual tensile stresses, and (3) temperatures in excess of about 120°F (49°C).
Austenitic Stainless Steel
304L Stainless Steel
Type 302, 304, 304L and 305 alloys are the most susceptible of all the Austenitic Stainless Steels to SCC.
References: Technical Data Blue Sheet, Allegheny Ludlum
Chemical Engineering, Oct 18, 1982 "
I think the biggest source of residual stress could be from welding, for our purposes, and our temps are higher than 120*F but I really don't think these things will be a problem for HBers.
http://www.centralboiler.com/stainless.html
Difference between 304(18-8{8%nickel}, or 18-10{10%nickel}) and 316 is the addition of 2% molybdenum, for better use in marine or harsh chemical environments.
Most stainless flatware ('silverware', table setting), is 18-8 or 18-10, both fall into either a 304 or 316 category, as the difference between the two is the molybdenum, which 304 has none. Seems the better flatware is 18-10.
My conclusion:
I see no reason to not use 304 stainless (18-8, or whatever) for ANY use that we home brewers typically see. The upgrade to 316 is not needed and is much, MUCH more expensive.
Here is why I started the safari. I wanted to buy SS mesh as was suggested by BobbyM (NOT picking on you, Bud, you are a TREMENDOUS HELP! ), to make a hopstopper and a Bazooka screen. When I went to look for what was available and what I really NEEDED, I had questions. Here's HOW MUCH MORE EXPENSIVE:
BobbyM's selection:
9241T432
(Same as 9241T43)
Strainer-Grade Woven Wire Cloth 304 SS, 60 X 40 Mesh,.0060" Wire Dia, 12" X 24" Sheet
In stock at $8.35 Each
The nearest choice in 316:
9319T628
(Same as 9319T174)
Super-Corrosion-Resistant 316 SS Wire Cloth 50 X 50 Mesh, .009" Wire Diameter, 12" X 24" Sheet
In stock at $22.74 Each
Hope this is some help; YMMV.
)At first I was gonna just post a question, asking the differences in stainless for what we are interested in, but instead, I just Googled and found out some info so here are easy links for your own info.
Basically, there seems to be two popular main types, 304 (also called 18-8 due to the chromium/nickel content) and 316.
http://www.machinist-materials.com/stainless_table.htm
http://www.machinist-materials.com/stainless_table_two.htm
From this page:
http://www.matweb.com/search/SpecificMaterial.asp?bassnum=MQ304A
Applications: beer kegs, bellows, chemical equipment, coal hopper linings, cooking equipment, cooling coils, cryogenic vessels, dairy equipment, evaporators, flatware utensils, feedwater tubing, flexible metal hose, food processing equipment, hospital surgical equipment, hypodermic needles, kitchen sinks, marine equipment and fasteners, nuclear vessels, oil well filter screens, refrigeration equipment, paper industry, pots and pans, pressure vessels, sanitary fittings, valves, shipping drums, spinning, still tubes, textile dyeing equipment, tubing.
From Sabco:
http://www.kegs.com/factsaboutkegs.html
"1) Kegs are made from fine, food-grade 304 stainless steel."
I have found some references to Stress Corrosion Cracking, caused by several things namely
"(2) residual tensile stresses, and (3) temperatures in excess of about 120°F (49°C).
Austenitic Stainless Steel
304L Stainless Steel
Type 302, 304, 304L and 305 alloys are the most susceptible of all the Austenitic Stainless Steels to SCC.
References: Technical Data Blue Sheet, Allegheny Ludlum
Chemical Engineering, Oct 18, 1982 "
I think the biggest source of residual stress could be from welding, for our purposes, and our temps are higher than 120*F but I really don't think these things will be a problem for HBers.
http://www.centralboiler.com/stainless.html
Difference between 304(18-8{8%nickel}, or 18-10{10%nickel}) and 316 is the addition of 2% molybdenum, for better use in marine or harsh chemical environments.
Most stainless flatware ('silverware', table setting), is 18-8 or 18-10, both fall into either a 304 or 316 category, as the difference between the two is the molybdenum, which 304 has none. Seems the better flatware is 18-10.
My conclusion:
I see no reason to not use 304 stainless (18-8, or whatever) for ANY use that we home brewers typically see. The upgrade to 316 is not needed and is much, MUCH more expensive.
Here is why I started the safari. I wanted to buy SS mesh as was suggested by BobbyM (NOT picking on you, Bud, you are a TREMENDOUS HELP!
), to make a hopstopper and a Bazooka screen. When I went to look for what was available and what I really NEEDED, I had questions. Here's HOW MUCH MORE EXPENSIVE:BobbyM's selection:
9241T432
(Same as 9241T43)
Strainer-Grade Woven Wire Cloth 304 SS, 60 X 40 Mesh,.0060" Wire Dia, 12" X 24" Sheet
In stock at $8.35 Each
The nearest choice in 316:
9319T628
(Same as 9319T174)
Super-Corrosion-Resistant 316 SS Wire Cloth 50 X 50 Mesh, .009" Wire Diameter, 12" X 24" Sheet
In stock at $22.74 Each
Hope this is some help; YMMV.
