What is Stainless steel: Definition and 79 Discussions

Stainless steel is a group of ferrous alloys that contain a minimum of approximately 11% chromium, a composition that prevents the iron from rusting and also provides heat-resistant properties. Different types of stainless steel include the elements carbon (from 0.03% to greater than 1.00%), nitrogen, aluminium, silicon, sulfur, titanium, nickel, copper, selenium, niobium, and molybdenum. Specific types of stainless steel are often designated by their AISI three-digit number, e.g., 304 stainless. The ISO 15510 standard lists the chemical compositions of stainless steels of the specifications in existing ISO, ASTM, EN, JIS, and GB (Chinese) standards in a useful interchange table.Stainless steel's resistance to rusting results from the presence of chromium in the alloy, which forms a passive film that protects the underlying material from corrosion attack, and can self-heal in the presence of oxygen. Corrosion resistance can be increased further by the following means:

increase chromium content to more than 11%
add nickel to at least 8%
add molybdenum (which also improves resistance to pitting corrosion)The addition of nitrogen also improves resistance to pitting corrosion and increases mechanical strength. Thus, there are numerous grades of stainless steel with varying chromium and molybdenum contents to suit the environment the alloy must endure.Resistance to corrosion and staining, low maintenance, and familiar luster make stainless steel an ideal material for many applications where both the strength of steel and corrosion resistance are required. Moreover, stainless steel can be rolled into sheets, plates, bars, wire, and tubing. These can be used in cookware, cutlery, surgical instruments, major appliances, construction material in large buildings, industrial equipment (e.g., in paper mills, chemical plants, water treatment), and storage tanks and tankers for chemicals and food products. The material's corrosion resistance, the ease with which it can be steam-cleaned and sterilized, and the absence of the need for surface coatings have prompted the use of stainless steel in kitchens and food processing plants.

View More On Wikipedia.org
  1. P

    Stainless steel and chromium oxide layer

    Stainless steel has a protective layer on its surface, which is 3-4 chromium oxide atoms thick. How is it possible that such a thin layer does not rub off immediately when we touch it?
  2. Flyboy

    Stainless Steel corrosion issue

    Not my issue directly, more a case of relaying the problem, but here goes. My girlfriend works for a company that makes bioanalytical units, and is part of their validation team in particular. They’ve started running into an issue with a stainless steel solenoid valve where it is, for lack of a...
  3. abdulbadii

    Stainless steel as ferromagnetic or non/paramagnetic

    Why is this stainless steel ferromagnetic while that one is non/paramagnetic, how's each proportion of them and what's its key difference that'd determines such the distinction?
  4. B

    B Thermos Bottle: Stainless Steel Inside & Out - 24h Cold & 12h Hot

    Manufacturer information: Interior material: stainless steel Exterior materials: Stainless steel Keeps cold liquid for: 24 hours Keeps hot liquid for: 12 hI was looking for a thermos bottle and came across a situation that I'm having a hard time answering. Why is the cold keeping time different...
  5. K

    Is ABS or Stainless steel more inert? (moved to Engineering)

    I'm going to purchases some flexible downpipe for my home, for toilets and kitchen, in the market I can find mainly stainless steel or ABS, which material is usually more inert to common home liquid wastes and chemicals? From time to time I will flush some drain unclogger or other cleaning...
  6. F

    Stainless Steel and Anodised Aluminium

    Hello engineers, Is it ok to use stainless steel bolts in an anodised aluminium clamp? I know that I should avoid using stainless steel with plain aluminium because of risk of corrosion. Also, what torque would you recommend that I apply to an M10 stainless steel bolt in an anodised aluminium...
  7. J

    Stainless Steel track surface grade to match a 440C roller?

    I have a machine I am designing that has a carriage supported by Track rollers on a machined flatbar track. The load that each individual roller will experience could reach 2000lbs. worst case scenario. The track surface is machined 304L - 1" wide as you can see in the green in the attached...
  8. K

    How to identify stainless steel?

    I know that stainless steel does not attract magnet, I know that stainless steel has appearance that looks like stainless steel, but sometimes it is quite difficult to tell. In addition to magnet test, any further test I can do in my home?
  9. S

    How much can a stainless steel tank rust inside?

    There is a lot of rusts in my water supply. I am suspecting the inside of my stainless steel pressure water tank is rusting. But can the stainless steel pressure tank rust inside? When i put magnet it doesn't stick to it. I plan to replace it with very expensive Aquaflow pressure tank because...
  10. Osvaldo

    Inserting Stainless steel blades into a Nodular Iron turbine diaphragm

    Would need some advise on how to prevent the blades from melting when pouring the nodular iron into the piece mold. If somebody has experience on the matter or can recommend literature that could help in developing a successful .
  11. M

    Is Stainless Steel or Aluminum with a Stainess Steel finish more durable?

    I would like to know if Stainless steel 304 or aluminum with a stainless steel finish would be more corrosion resistant when outdoor 24/7/365 exposed to the sun, rain, snow, etc. but not salt. Not a coastal climate. Both materials are resistant to corrosion and are sold as fixtures, etc. but I...
  12. S

    Pressure of Slurry in a Stainless Steel Pipe

    I am trying to find the pressure in a ANSI stainless steel pipe with a nominal diameter of 10 in. A slurry of fiberglass and water is flowing through the pipe that has a viscosity of 3.2 centipoise. The flow rate through the pipe is approximately 3000 GPM. How can I figure out the pressure in...
  13. K

    What is the agent used to stick silicone and stainless steel together?

    Sorry probably a little bit out of the track of Chemistry but it's still Chemistry. I'd like to know what is the combining agent we can find in the consumer market that is used to stick silicone stuff with stainless steel?
  14. P

    Which grade of Stainless Steel is more soft or ductile in Sheet form?

    I want to make a small item in Stainless Steel Sheet of 1.2 mm thick, 18 inch width & 24 inch length, by "Metal Forming & Punching of Holes". Please suggest me, which grade of Stainless Steel Sheet is more soft or ductile? It has to be economical as well. Thank you.
  15. Spinnor

    Plumbing Stainless steel house water filter, leaks past o-ring

    Bought a stainless steel whole house water filter for a very good price ($100), turns out too good. On inspection I suspected it would leak so rather then installing it into the house water system I pressure tested it. There was a small leak that stopped after a minute or so. Relieve the...
  16. A

    303 Stainless Steel tapping

    Hello friends. First, I apologize for my bad English. I need your experience. I want to produce a piece, but I have a problem with tapping. The material is 303 stainless steel. I need a M2 tapping to this part. Approximately 200-300 pieces of M2 tapping will be made. For 303 stainless steel...
  17. G

    Stainless steel 304 "Stainless" properties

    Hi, my first post. I hope some one can help. I work for a manufacturer and we make a particular item from 304 stainless. We have two parts we put together and then stamp (rivet) to hold in place. When we perform a 48 hour salt spray we occasionally find the there are small 'rust or brown'...
  18. F

    Does chromium oxide reduce conductivity in stainless steel?

    Does chromium oxide reduce the effectiveness of a faraday cage constructed from stainless steel mesh? I am using mesh that is like insect screen for windows. It will be in moist environment. I appreciate your help!
  19. K

    Could heating stainless steel release any harmful materials?

    Today, I turned on an electric kettle for heating up some water, then I going to did something else. Since the cover of the kettle was lost, it didn't automatically stop when boils, and I forgot to turn off the kettle when boiled, then all the water vaporized at last and the kettle stopped...
  20. P

    Stainless steel friction / galling

    Hi, I’m looking for some advice on materials. In the picture A, B and C are stainless steel. Pressure is applied at B rotating D in the socket and raising A. D needs to be as strong as possible to resist the load but I’m concerned about D rubbing against C as there is no lubrication. I can't...
  21. D

    Galling of 303 vs. 304 when coupled with 416 Stainless Steel

    I was looking for an appropriate galling resistance stress for a slow moving part I'm designing. You can think of it as a hinge. I found the article linked below which seemed very helpful. Table XI on page 24 shows various galling resistances, including my wear couple 303 vs. 416 Stainless...
  22. N

    Effect of a lightning strike on stainless steel bolt

    Hello, I was recently onsite in the Philippines and the equipment owner stated their wind turbine had been hit by lightning. The only obvious damage was to the bolted connections at the root of one blade. One was sheared, the other bent. Does anyone have any experience of lighting causing...
  23. S

    What is the difference between 304 and 201 stainless

    well,recently one of my customer ask me how is the difference between stainless steel 304 and 201,and i can found out the chemical property difference.but i can find the physical difference. is there somebody can help me? 304 introduce http://www.sd-steelplate.com/Product/Stainless-steel/1/ 201...
  24. F

    Does non-magnetic or magnetic stainless steel leach more?

    May I know whether non-magnetic or magnetic stainless steel cookware leach more? I have looked at the different reasons why some stainless steel is magnetic or not, but it is confusing me whether one leaches more than the other.
  25. kolleamm

    What is the most effective tap for threading stainless steel?

    I need to know what is the strongest most reliable tap for threading 6-32 into stainless steel. I used like 3 cheap steel taps and they all broke. Any advice is greatly appreciated. Thank you
  26. P

    What is the Maximum Torque Needed for Failure of a Serrated Plate with 48 Teeth?

    If I had 2 serrated plates like the ones in the attached picture locked in place like seen below. How would I go about calculating the maximum amount of torque needed for failure of the part. Assuming it has 48 teeth and is made from stainless steel?
  27. T

    Microchannel Array etching in Stainless Steel Metal Search

    Hi All! Haven't been here for some time, the changes are looking good! Anyway, formalities aside, I am having serious problems sourcing and implementing a suitable stainless steel (Grade: 304; thickness: 0.3mm) substrate for my etching process. I'm currently working on developing a...
  28. yangshi

    303 Stainless Steel Properties at High Temps

    Does anyone have a source for 303 stainless steel mechanical properties (YS, UTS, modulus, poisson's) with variation to temperature, especially around 800C? I've been searching a lot of sites... Or would it be fine to assume 303 has "good resistance to scaling at up to 871C" from...
  29. caters

    Why is my stainless steel spoon oxidizing?

    I noticed on 1 of my stainless steel spoons that a film of Iron(II) oxide(which is a black rust) formed. I have been taught that stainless steel will not rust. So why would a stainless steel spoon be oxidizing?
  30. mesa

    What is the best material for cryo ball mill cup assembly?

    I am working with a set of alloys that must first be ground up in a ball mill at cryogenic temperatures. It is important that no contamination makes it into the material and careful steps are taken to ensure this end. Unfortunately when we ran a set of samples through our RBS lab and then again...
  31. jmex

    Casting grades for different materials

    Hello, I am confused with casting grades of different steel,for example 316 SS has casting grade CF8M. What does it mean and where can i find grades of other materials as well like 316L, 304L. 304, CS, etc. Any data sheet showing grades for every material will be helpful. Thanks
  32. deuel18

    Build a Hydrogen Generator with Stainless Steel Plates

    Hello. I just want to know if you guys know a website, place, or store where you can use their apparatus and work on a stainless steel plate? Right now I'm planning to create a Hydrogen generator using water with catalyst. Thank you.
  33. S

    Battery school project assistance

    Hello everyone! I'm almost done with a project of mine and I'm creating a battery with an aluminum casing around. Inside I have a copper electrode (cathode) and due to lack of finding a correct dimension I have to resort to using a stainless steel anode (and I'm also running out of time) So I...
  34. A

    Stainless steel tube weight load

    I'm building a sun cover for my open air atrium. Dimension is 8x8 ft. I'm building with clear cedar(ver expensive). In one direction, I'm placing 19 8ft 2x4 cedar boards tilted vertical and spaced 5 inches apart. Knowing the boards spanning 8 ft, anchored at both ends to the square frame...
  35. T

    Stainless steel crystal structure

    Hi, I'm looking for a simple s.s crystal unit cell structure and can't find it anywhere. I understand that stainless steel is a very general word and takes many forms and has many different types, but isn't there a standard type that people use in the industry and ususlay talk about when they...
  36. C

    Heat transfer from water in a stainless steel pipe: analysis

    Hi Guys, this is my first post and I'd love a bit of help here, appreciated this may seem basic but it's been a few years since I did this last. I have water in a stainless steel pipe (ID = 0.0381m, OD = 0.0411m) network of roughly 10m length, at 120 bar, roughly 50°C (+ or - 5). This water...
  37. R

    Is Stainless Steel a non ferrous metal?

    Read this quote on a major recycler's website: "During this processing, we separate ferrous materials from nonferrous and further separate the copper, aluminum, brass, stainless steel, and other metals from the stream of nonferrous metals. " Is Stainless considered non-ferrous? Why? Isn't it...
  38. R

    Coating a Stainless Steel Lab Reactor

    We have a small lab reactor (~2 Litres) made of stainless steel that we use to test reactions. Unfortunately, we now have one test which has a hot acidic environment (dil. HCl approx. 20%) that would corrode the native stainless steel. Is there any way to work around this? Maybe a...
  39. E

    Connecting aluminum profile with stainless steel

    We are building a light detection system which works like a clock’s hand: an aluminum profile (the “hand”,shown in schematics) carrying detector assemply on its one end rotates around the other end; as the aluminum profile is quite long (2200L*40W*40H mm) and heavy (~10kg),we will add a...
  40. B

    BTU transfer of stainless steel pipe

    I know this is a complicated question, and depends on a lot of factors. So, I will do my best in explaining the situations. I am trying to regulate the temperature of a pool of circulating water. I have 8' of stainless 304, 1" OD, 14 awg, pipe, positioned against the flow of water (to provide...
  41. S

    Stainless steel cooling container, need some help with the maths

    Hi guys, I'm designing a cooling device as part of a project and need a little help with the maths. OK, so the scenario is this, take boiling water, put it in a stainless steel container with Thermal Conductivity of 8.7 Btu/h ft °F and dimensions of 15.811cm x 15.811cm x 1 cm to store 250ml...
  42. L

    Comparison between aluminium and stainless steel

    I am looking for a paragraph on each metal on the comparison of aluminium and stainless steel under the heading: Manufacturing Methods: What processes are available to turn the raw material into products and how do the processing methods differ? Regards, Lockyphysics
  43. M

    Will an oscillating magnetic field penetrate a stainless steel tube?

    I am a chemical engineer, not a physicist, so I am a bit rusty on my electromagnetics. I need to set up a fluctuating magnetic field inside of a stainless steel tube (hopefully using a pair of electromagnets outside the tube), and I am wondering if the field will penentrate through the tube...
  44. A

    Can Copper and Stainless Steel be Separated?

    I heard a rumor from some people at a scrap yard that it's impossible to sepperate copper from stainless steel, and that the copper ruins the stainless steels structual integrety. Is there any truth to this?
  45. P

    Why does aluminum leech into a water bottle, but stainless steel does not?

    Why does aluminum "leech" into a water bottle, but stainless steel does not? My professor was saying that using aluminum water bottles will result in a small amount of aluminum ions dispersing into the water. Stainless steel, however, does not have this problem. Is this true? Why? I'm...
  46. G

    Bending of Stainless steel pipe

    We have a design of stainless steel pipe with a bend radius of 1.5 The OD of the pipe is 47mm and the wall thickness is 3mm. Can anyone tell me if this is possible please? I am pretty sure the SS is austenitic. I thought that as a rule the minimum radius was 2. Thank you
  47. M

    Stainless steel pipe selection

    dear friends i have an application for pumping system it consists of 3 parallel pumps having a max head of 8 bars i have a stainless steel pipe has 8" diameter and sch 10 will this be suitable to be used under this pressure ?
  48. B

    Regaining surface finishing after hardening stainless steel

    Hi! We are going to machine some stainless steel parts that will require hardening afterwards. The parts are going to be hardened in an oven at 600 degrees celcius for 4 hours and then air cooled. This procedure is given in the suppliers data sheet. Because I'm new in the game of...
  49. T

    Fatigue calculations for stainless steel seamless tubing

    Looking to understand Fatigue calculations for stainless steel seamless tubing Problem: Material: 304 Stainless Steel tubing (.375 OD, .072 wall) per ASTM specifications used at 158F degrees maximum Ambient UTS 515 MPa, YTS 205 MPA, temperature de-rated per MIL-HDBK-5J to UTS 473.8 MPa, YTS...
  50. T

    Heat loss through stainless steel tubing

    Please redirect me to the appropriate forum if I have posted in the wrong place... This stuff is FAR over my head, and I need somebody with some real knowledge of thermodynamics and heat flow... I own a scuba dive shop and of course we compress air to very high pressure, on the order of 300...