SS Splints 316 or 304?

Jakob Hilditonn · Post by **Jakob Hilditonn** » Thu Aug 31, 2006 10:14 pm

I'm looking to add some stainless steel splints for the inside of a kidney belt (SCA protection) Looking on http://www.metalexpress.net and they carry two kinds of stainless, 316 and 304. Which one would be better suited to my intended use?

Alcyoneus · Post by **Alcyoneus** » Thu Aug 31, 2006 10:46 pm

The short answer is that while 316 is a bit stronger, I don't think it is terribly noticeable in what we do. It is also a little more corrosion resistant, but again, not terribly noticeable for what we do. If it is the same price new, I might buy the 316, but at surplus/scrap prices, I'll take what I can get. I'll often buy the stuff for laser cutting because it still has the protective plastic on one side.

Long answer?

http://www.matweb.com/search/SpecificMa ... num=MQ304A

304SS

Material Notes:
Austenitic Cr-Ni stainless steel. Better corrosion resistance than Type 302. High ductility, excellent drawing, forming, and spinning properties. Essentially non-magnetic, becomes slightly magnetic when cold worked. Low carbon content means less carbide precipitation in the heat-affected zone during welding and a lower susceptibility to intergranular corrosion.

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.

Corrosion Resistance: resists most oxidizing acids and salt spray.

Hardness, Brinell 123 123 Converted from Rockwell B hardness.
Hardness, Knoop 138 138 Converted from Rockwell B hardness.
Hardness, Rockwell B 70 70
Hardness, Vickers 129 129 Converted from Rockwell B hardness.
Tensile Strength, Ultimate 505 MPa 73200 psi
Tensile Strength, Yield 215 MPa 31200 psi at 0.2% offset
Elongation at Break 70 % 70 % in 50 mm
Modulus of Elasticity 193 - 200 GPa 28000 - 29000 ksi
Poisson's Ratio 0.29 0.29
Charpy Impact 325 J 240 ft-lb
Shear Modulus 86 GPa 12500 ksi

http://www.matweb.com/search/SpecificMa ... num=MQ316A
316SS
Material Notes:
Molybdenum content increases resistance to marine environments. High creep strength at elevated temperatures and good heat resistance. Biocompatible. Fabrication characteristics similar to Types 302 and 304.

Applications: food and pharmaceutical processing equipment, marine exterior trim, surgical implants, and industrial equipment that handles the corrosive process chemicals used to produce inks, rayons, photographic chemicals, paper, textiles, bleaches, and rubber.

Corrosion Resistance: better corrosion resistance than 302 and 304; resists sodium and calcium brines; hypochlorite solutions, phosphoric acid; and the sulfite liquors and sulfurous acids used in the paper pulp industry.

Mechanical Properties
Hardness, Rockwell B 79 79
Tensile Strength, Ultimate 580 MPa 84100 psi
Tensile Strength, Yield 290 MPa 42100 psi
Elongation at Break 50 % 50 % in 50 mm
Modulus of Elasticity 193 GPa 28000 ksi in tension
Charpy Impact 105 J 77.4 ft-lb V-notch
Izod Impact 129 J 95.1 ft-lb

pippin · Post by **pippin** » Fri Sep 01, 2006 1:09 am

i work in a bbq store. (this is going somewhere)

the place i work at uses 304, the only real diffrence between the 2 is the rate of corrosion, if you activaly try to get 304 to rust it will, 316 wont, its considered marine grade. its a bit stronger due to the higher concentrations of the heavy metals Nickle and cromium (depending on who makes it)...

304 should be fine. and much cheaper....

pip

RandallMoffett · Post by **RandallMoffett** » Fri Sep 01, 2006 5:57 am

is 316 weight wise heavier then? Even noticible?

RPM

Alcyoneus · Post by **Alcyoneus** » Fri Sep 01, 2006 6:03 am

They are identical.

Jakob Hilditonn · Post by **Jakob Hilditonn** » Fri Sep 01, 2006 9:44 am

More corosion resistant, virtually the same weight and strength, and its only costing my $4 more for the splints. 316 it is then, thanks guys.

Nice sig Alcy...

RandallMoffett · Post by **RandallMoffett** » Fri Sep 01, 2006 9:47 am

interesting... is it usually more expensive?

RPM

Cet · Post by **Cet** » Fri Sep 01, 2006 10:02 am

The primary diference between the two is a higher percentage of nickle in the 316 which makes it more expensive. In use I haven't found a functional difference betwen 304 and 316

Mike England · Post by **Mike England** » Fri Sep 01, 2006 10:07 am

McMaster has a good database and you can get some idea of pricing through them although you local supplier will probably be better.

http://www.mcmaster.com/nav/framework.a ... less+Steel