While stainless steel is simply that to most people, the term encompasses various grades of steel, each of which has a slightly different alloy composition. 303 stainless steel still has strong corrosion resistance, but for an added boost, we recommend 304. However, its relative weakness means it isn't used as often as grade 304 stainless steel. Grade 304, which is easier to weld, usually winds up in auto parts or construction materials. 303 stainless steel is a free-machining grade of 304 that has sulfur added to increase its machinability. Free-machining stainless steel may only be 40 to 50% as efficient to machine as brass. However, this slightly does lower the corrosion resistance and toughness of the metal. 303 gains its improved machining and galling characteristics by the addition on sulphur, however this addition also lowers the stainless steels corrosive resistance and reduces its toughness slightly when comparing it to 304 Stainless Steel. Its composition contains at minimum 17% Chromium, 8% nickel, and 0.15% Sulfur/Selenium. 316 work hardens much worse than 303 and it tends to produce stringy chips. It's not as corrosion resistant as 304 stainless steel, but it still stands on its own. This alloy's composition makes it ideal for corrosion-resistant, strong, long-lasting fasteners. Corrosion resistance 303 has relatively good resistance to mild environments, but it's significantly less than 304 stainless steel. Brackets are 0.2756" x 0.2835" x 5.4331". Improved machinability. My GUESS is that you smell only the 303 parts, and not the 304. The addition of this transition metal increases 316's corrosion resistance and also imparts high heat resistance of up to 1600F. I'll have to take another look at their bulldog handle. It is austenitic and non-magnetic in the annealed condition. Average cutting speed 130 ft/min. Whereas 416 can be heat treated. Stainless Steel Grades: 303 - 304 - 420 . . However, they can be magnetic to a small degree, especially in formed parts. In room temperature conditions, grade 301 stainless can take up to 120 ksi (kilopounds per square inch). Excellent machining characteristics Free machining version of Types 302 and 304 is used for parts requiring extensive machining. It is very similar in chemistry to 303, the main difference being the lack of sulfur. Sandmeyer Steel offers Alloy 303 in thicknesses from 3/16" (4.8mm) through 2" (50.8mm). 303 stainless steel is specifically made for machining applications, whereas many 304 grades can be difficult to machine. Grade 304 and 316 are the most important members of the Austenitic family and are the most widely used. In contrast, Alloy 303 is the easiest stainless steel to process. This machinability has made it very popular in the fastener industry, particularly in the manufacture of spacers and standoffs. Stainless steel hex bar 303 features an annealed cold finish and is renowned for its corrosion resistance and high machinability. The choice of material affects the ratio of machinability to cost. It is typically used in aircraft applications, machine . . The Austenitic grades are generally nonmagnetic and hardenable only by cold working. Machinability of Stainless Steel ranges from free-cutting grades like 430F and 303 that have machinability of 75%, and to up challenging grades like 316 with Machinability of 36%. Alloy 303 is a non-magnetic, austenitic stainless steel that is not hardenable by heat treatment. Usability: Since it is easy to machine, grade 303 steel is often used to craft fine, intricate pieces such as screws, bolts, nuts, and shafts. Stainless Steel Pipe & Tubing; Blog; Resources. 2. Videos; Machinability Ratings; . It also has a higher level of corrosion resistance, including when exposed to salt water. Stainless Steel is the 2 nd most popular materials group (After Steel) in machine shops. The addition of sulfur or selenium increases the machinability. Here are five things you need to know about stainless steel machining. Stainless steel floats The main difference between 304 vs. 316 stainless steel involves the 316 grade's much higher levels of molybdenum, which are typically 2-3 percent by weight and provide better corrosion resistance. Machinability Grade 303 stainless steel has excellent machinability. other 400 series stainless steels which do not contain higher sulfur levels. About; Contact Us; 800-531-9500 . It contains 18 percent chromium and 8 percent nickel. Type 316 Composed of slightly higher levels of chromium (16-18%) and nickel (10-14%) than types 303 and 304, the most distinguishable properties of 316 stainless steel come from the addition of 2-3% molybdenum, an element which significantly improves the alloy's corrosion resistance. It is the free machining modification of the basic 18% chromium / 8% nickel stainless steel. They have a moderately high 94% of their average alloy composition in common. There are 33 material properties with values for both materials. Grade 303 stainless steel cannot be hardened by heat treatment. Stainless Steel 303 Hex Bar Applications Washers Nuts Fittings Screws Mounting applications Ornamental work Cost . While the sulfur content does decrease its corrosion resistance and . 303 is a free-machining grade of 304 stainless steel that contains added sulfur or selenium. Messages. Next Last. The melting range of stainless steel 302 is between a temperature range of 2550 F - 2590 F. And in the temperature range that melts austenitic stainless steel 304 is between 2,550 F - 2,650 F. Most stainless steel handed down around the world is Grade 304. Machinability of AISI 316 austenitic stainless steel was evaluated in terms of thrust force, tool life, surface roughness, and hole quality of the drilled holes. Machining can be enhanced by adhering to the following rules: Cutting edges must be kept sharp. 1.4305 A Free-Machining Austenitic Stainless Steel Developed for The type of 303 represents the best performance in machinability, compared with the other austenitic stainless-steel types. What is better 304 or 316 stainless steel? May 15, 2014 #1 Hello all, Looking at stainless steels for bolsters, guards, folder liners, etc - 303 SS is listed as a machinable and 416 is listed as machinable, but 410 isn't listed as to machinability. Which great increase the risk of hot cracking. Stainless Steel grade 303 has good resistance to mildly corrosive atmospheres (lower than SS304) and good oxidation resistance at temperatures up to 1700F. Here are a few resources for more guidance on stainless steel grades: 304 vs. 316 stainless steel tubing; 316 vs. 316L stainless steel; Stainless steel vs. carbon steel tubing; Cost of stainless steel tubing vs. aluminum tubing ; Either way, always know your metal! 316 stainless steel boasts a higher strength and durability than 304 stainless steel. Machinability is rated at 78% of B1112. It is best suited for materials that require repeated machining including fabricating fittings and fasteners. It also maintains the mechanical and corrosion resistance common to stainless steel. Properties with values for just one material (2, in this case) are not shown. Alternatively, 316 SS fasteners tend to be used by . This means it is not as easily machinable, but it offers improved corrosion resistance and toughness. The addition of sulfur or selenium increases the machinability. Have a look at our machinability rating graph which without a doubt will make your decision a lot easier with its incredibly detailed . It is also harder to polish. 316 grade has almost the same physical and mechanical properties as 304 stainless steel. Last edited: Jul 13, 2015 Jul 13, 2015 #7 The 304, and more especially the free machining 303 types, should not be considered suitable for seawater service. The main difference between 304 and 316 stainless steel is the fact that 316 stainless contains a significantly increased amount of molybdenum. Its composition contains at minimum 17% Type 303 Stainless Steel Type 303 stainless steel is a non-magnetic, austenitic steel which is non-hardenable by heat treatment. While 316 comes in second in the quantities sold, it provides highly superior resistant oh corrosion to acids and chlorides. Type 303 is a material of choice for Swiss-type lathe turning. 303 stainless steel is a free machining grade, meaning it has controlled amounts of manganese sulfide inclusions to help break the chips when you machine it. 304 Stainless Steel. It is non-magnetic in it's standard state, but can become magnetic as a . First off, what do 303, 304, and 316 stainless steels have in common? Selection of 316, 304 and 303 types of stainless steels for seawater applications . It's also the choice for aircraft fittings and gears as well as . I'm thinking about making a large bowie (10" blade) and noticed that some makers use 303 stainless whereas others use 416 stainless for the guard. Cutting 303 cold drawn stainless steel in a haas vf4ss mill. Also, 316 is slightly more resistant to salt water corrosion than 303. Annealing range is between 1850 and 2050F. The main value of 303 stainless steel is its ease of machining, grinding, and polishing due to the presence of Sulphur in the alloy. 303 vs 304 vs 316 Stainless Steel. First Prev 2 of 3 Go to page. The main difference between 304 and 316 stainless steel is the fact that 316 stainless contains a significantly increased amount of molybdenum. 04-19-2011, 07:28 PM #10 304 and 304L have the same machinability rating of 70. It is particularly desired for automatic machining operations for this reason. Properties with values for just one material (1, in this case) are not shown. AISI 303 is cannot be hardened by heat treatment, but tensile and hardness can be increased by cold working with subsequent reduction in ductility.The sulfur . Notice the comparison of the 303 free-machining steels with the machinability of the standard 304/316 austenitic stainless steels. Type 303Se contains Se and P added to improve machinability. It is mainly used when manufacturing contains huge machining in the machines of the automatic screw. The addition increases corrosion resistance, particularly against chlorides and other industrial solvents. Slightly magnetic when cold worked. I needed some SS jam nuts one time, and since I couldn't find any in stock locally, I just cut down the quantity of regular hex nuts I needed into jam nuts. Download Download PDF. Cold working increases tensile strength and hardness. Go. nick . Machining Stainless Steel 303 303 is a free-machining stainless alloy providing the best machinability among the austenitic stainless alloys. But despite this, it remains a tough, austenitic stainless steel alloy. Alloy 303 is subject to corrosion cracking in chloride environments above 60, and in the humid marine environment, it is easy to suffer from . The maximum carbon content for 316 stainless steel is 0.08%, whereas for 316L, it is 0.03%.i.e.steel 316L is low carbon steel This steel iis more resistant to carbide precipitation and can be used . It isn't as good as 316 for food grade and it isn't as consistent as 316 or 303 free machining either, in my experience. 303 vs 316 stainless steel for handles. That makes grade 303 steel the first choice for fittings, gears, and fasteners where tight tolerances are a must. Basically all stainless steel combinations such as 303, 410, 420, 416, 17-4, 15-5 will gall with each . It performs well against pitting and is also resistant to caustic chemicals. Switch from 303 to 304 and I'd bet your problem will vanish. In this paper, machinability of AISI 316 austenitic stainless steel was investigated using cryogenically treated and untreated high-speed steel (HSS) twist drills. 303 stainless steel is similar to 18-8 stainless, but has a larger sulfur content, making it one of the more machinable stainless steel grades. Annealed condition is non-magnetic. AISI 303 Stainless Steel vs. AISI 316 Stainless Steel Both AISI 303 stainless steel and AISI 316 stainless steel are iron alloys. 303, 303Se, 303MA, 135-275.76 - .48 : 303Pb, 303Cu, 303 Plus X : Martensitic: 416, 416Se, 416 Plus X . Why are you changing from the common 303 (austenitic with added sulfur and phos to aid machining) to the rarer 17-4 (semi austenitic precipitation hardening grade)? In addition, it contains selenium or sulfur, which makes it highly machinable. The tensile strength of the 303 is about 720MPa where the tensile strength of the 304 material is only around 515MPa. Direct contact with these metals can help improve the resistance of the 316 types of stainless steel, at the expense of the other metal. That said, grade 303 steel is, for the most part, unweldable. 316 is a tool killer. It provides additional corrosion resistance, high flexibility, superior appearance and abrasion resistance. With these additional elements, 303 offers increased machinability. Buy Stainless Steel online at metals4U EN 1.4305 grade 303 Stainless Steel provides the best machinability among all the austenitic Stainless Steels. For each property being compared, the top bar is AISI 303 stainless steel and the bottom bar is AISI 416 stainless steel. 303 also meets the 18-8 designation. By Metarinka Date 03-10-2010 23:47. It still provides excellent formability when compared with many other types of stainless steel, as well as ease of fabrication and weldability. There are 34 material properties with values for both materials. Stainless and is the most widely used of the chromium nickel stainless and heat resisting steels. You need to keep speed down, I go as low as 200sfm with carbide, and keep the depth of cut and feed up no dawdling about taking off .01" at .001" ipr; try to keep at least .03" doc and a feed like 0.005. Cost: Both grades of steel are generally affordable. 304 is a non-magnetic austenitic stainless steel that is known for its excellent forming and welding characteristics, and its good corrosion resistant . Generally 303 is considered unweldable due to free machining alloys added. The machining cost factor is about half of 304 and 316 stainless steel. 303 Stainless Steel. As mentioned above, however, 316 stainless steel is less malleable than 304 stainless steel. Molybdenum & Stainless Steel Type 303 stainless is a free-cutting material, with the best machinability of any austenitic stainless steel. In addition to the machinability differences between the various types of stainless steel, this makes grade 316 steel easier to process than 316B. Good advice. There Are Two Common Types of Stainless Steel - 304 and 316. Austenitic Stainless Steel. And its machinability at least partially makes up for the difference. It meets standard corrosion requirements at a lower cost than the higher grade material. Weld Wire; Round Bar; This grade is equivalent to 303 in regard to corrosion resistance. Since the basic chemistry of both grades 304 and 302 are similar, the alloys have an overlap in their melting point. 316 Stainless Steel Contains a minimum of 16% chromium, 10% nickel and 2% molybdenum. 303 Stainless Steel. Rolled Alloys Machining grade of 316/L stainless steel for improved machinability and outstanding uniformity.. PRODEC 17-4. Too many people make the mistake of lumping all of the 300 series stainless into a group and assume they all act the same. Do not clean stainless steel with steel wool (as it can embed iron particles and lead to pitting corrosion) Inventory. 303 has a machining cost factor of 2.7 when compared to standard steel. This increase in molybdenum results in increased corrosion resistance. 2,039. Grade 304 stainless steel, by comparison, can only take up to 90 ksi of pressure before . It has a machinability level of 150 and a baseline machinability level of 100. Thread starter Grandpa Pipes; Start date Jul 12, 2015; Prev. Stainless machining is a precise art and science. Increases of 25% or more in machinability can be achieved by using those free-machining grades. 303 makes a great stainless to use for knife hardware, and is the free-machining of the 300 steels, with the addition of a good amount of . Maxival is a technologically advanced process carried out on conventional stainless steels such as Type 304 and 316. 303 is an "18-8" chromium-nickel stainless steel modified by the addition of selenium or sulphur, as well as phosphorus, to improve machinability and non-seizing properties.. . Another difference between the 304 and 316 is the cost of the material. 303 vs 304 vs 316 Stainless Steel. . It is a general-purpose stainless of which there are numerous modifications. Machinability ratings assign efficiency ratings to materials of similar composition, so generalities can be made. 316 steel has a machinability rating of 60, while 316B has a machinability rating of 50. Specification Sheet: Alloy 303 (UNS S30300) W. Nr. Stainless Steels, Cast : Ferritic: ASTM A217: Grades C5, C12: 135-185: 0.60 : ASTM A296: Grades CB-30, . When made into fasteners, the 304 SS tends to be more affordable. Interesting that Weber uses 316. Jun 17, 2007. 303 Stainless Steel. #1. 316 "work hardens" faster than 303. Had the hex nuts in stock at the shop, box marked 18-8. Machinability Ratings - Stainless and Super Alloys Electrical Steels. Experimental results showed from 14% to 218% improvements for treated . The machinability rating is approximately 75%. As I understand it, 303 stainless is easier to machine than 416, but is softer and unheat-treatable. Grade 301 stainless steel, with its higher carbon content (0.15% compared to 304's 0.08% by weight), can better withstand mechanical force. Type 304 stainless doesn't harden with heat treatment and is not a free-cutting material, making it less than ideal for use in machining. Stainless Steel Machinability Graphs What is stainless steel? In order to obtain optimal corrosion resistance, it is recommended that Alloy 303 be chemically treated to remove sulfides from the final surfaces. Machinability vs. It offers the model corrosion resistance, strength, easy maintenance, and formability, for which stainless is known. Dec 20, 2005. Jul 14, 2015 #21 S. StuartV. 304 Stainless Steel Comprising 18% chromium and 8% nickel, type 304 stainless steel is sometimes referred to as 18/8. So 303 is widely used to make accurate machining parts. The machinability grade of 316 steel is 60, while the machinability grade of 316B is 50, and the machinability grade of 304 and 304L grades is the same, both are 70. For this reason, 304 SS products are more popular among consumers. Suncor Stainless mainly uses grade 304 and 316 stainless steel from the 300 series.