AISI 310S Round Bars

AISI 310S hot rolled round bar is a high chromium, high nickel austenitic bar for parts that work hot, such as furnace rollers and kiln supports.

16 to 125 mm Austenitic stainless steel Made to order

HOT ROLLED ROUND BARS

AISI 310S hot rolled round bar

AISI 310S hot rolled round bar is round bar rolled from an austenitic stainless steel made for continuous service in hot air and combustion gases. Its chromium builds the oxide film that resists scaling at temperatures where AISI 304 and AISI 316 lose it, and its nickel holds the austenitic structure through repeated heating and cooling. AISI 309S, the grade one step below, carries less of both elements and gives out at a lower temperature. AISI 310 shares the same chromium and nickel range but allows carbon up to 0.25 percent; the S grade holds carbon to 0.08 percent, so less chromium carbide forms at the grain boundaries and a welded joint keeps more of its corrosion resistance.

The bar is supplied solution annealed, heated until the carbides go back into the metal and then cooled fast so they stay there. In that condition it is non-magnetic, it cannot be hardened by heat treatment, and it gains strength only by cold work. ASTM A276 sets 515 MPa tensile strength and 205 MPa yield strength as the annealed minima. The grade work hardens under the tool, so turning it asks for sharp edges, a firm feed and lower speeds than carbon steel. It is welded with a matching 310 filler and without preheat. Round bar in this grade is machined into furnace rollers and hearth fixtures, radiant tube and burner parts, kiln and annealing furnace supports, and shafts for heat treatment equipment.

Composition limits in weight percent are carbon 0.08 maximum, manganese 2.0 maximum, sulphur 0.03 maximum, phosphorus 0.045 maximum, silicon 1.5 maximum, chromium 24.0 to 26.0 and nickel 19.0 to 22.0.

SPECIFICATION

AISI 310S hot rolled round bar supply conditions

Size range: 16 mm - 125 mm (5/8" - 5")
Length: Up to 8 metres
Tolerances: ASTM A484, EN10060
Heat treatment: Solution annealing
Grade: AISI 310 S (310S, SUS 310S, 1.4845, S31008)
Family: Austenitic stainless steel
Supply: Made to order in this grade; every published size of the form

Composition of AISI 310S

Element	Symbol	Minimum %	Maximum %
Carbon	C		0.08
Manganese	Mn		2.0
Sulphur	S		0.03
Phosphorus	P		0.045
Silicon	Si		1.5
Chromium	Cr	24.0	26.0
Nickel	Ni	19.0	22.0

Composition, weight percent, balance iron. From the Laxcon Steels grade reference.

Equivalents of AISI 310S

Standard	Designation
UNS	S31008
EN number	1.4845

Equivalence means nearest counterpart, not identity: each standards body sets its own composition window, so the limits of the standard named on the order govern.

Pitting resistance

The pitting resistance equivalent number of AISI 310S runs from 24.0 at the specified minimum chromium, molybdenum and nitrogen to 26.0 at the maxima, computed as PREN = Cr + 3.3Mo + 16N (International Molybdenum Association). It ranks resistance to chloride pitting against other austenitic and duplex grades and nothing else: it does not predict crevice corrosion, stress corrosion cracking or service life. The pitting resistance reference carries the full table.

Governing standards

EN 10088-3: Stainless steels: technical delivery conditions for semi-finished products, bars, rods, wire, sections and bright products for general purposes. Composition, heat treatment condition and mechanical properties per grade.
EN 10060: Hot rolled round steel bars for general purposes: dimensions and tolerances on shape and dimensions.
ASTM A276/A276M: Stainless steel bars and shapes: composition, condition, mechanical properties and finish designations for hot-finished and cold-finished bar.
ASTM A484/A484M: General requirements for stainless steel bars, billets and forgings: permissible variations in dimensions, straightness, weight and length, and the test and marking requirements every bar order inherits.
ASTM A479/A479M: Stainless steel bars and shapes for use in boilers and other pressure vessels: the bar specification a pressure-part drawing calls for.
ASTM A314: Stainless steel billets and bars for forging.
NACE MR0175 / ISO 15156: Materials for use in H2S-containing environments in oil and gas production: the sour-service limits on hardness and condition.
EN 10204: Metallic products, types of inspection documents: the 2.2 test report and the 3.1 and 3.2 inspection certificates a purchase order can call for.

Weight per metre

Diameter (mm)	kg per metre	Metres per tonne
16	1.59	629.5
17	1.79	557.6
18	2.01	497.4
19	2.24	446.4
20	2.48	402.9
21	2.74	365.4
22	3.00	333.0
23.2	3.34	299.4
24	3.57	279.8
25	3.88	257.9
26	4.19	238.4
27	4.52	221.1
28	4.86	205.6
30	5.58	179.1
32	6.35	157.4
34	7.17	139.4
36	8.04	124.4
37	8.49	117.7
38	8.96	111.6
40	9.93	100.7
42	10.95	91.4
45	12.57	79.6
47	13.71	73.0
48	14.30	69.9
50	15.51	64.5
53	17.43	57.4
56	19.46	51.4
57.5	20.52	48.7
60	22.34	44.8
63	24.63	40.6
66	27.03	37.0
67.5	28.27	35.4
70	30.40	32.9
73.5	33.52	29.8
75	34.90	28.7
77.5	37.27	26.8
80	39.71	25.2
83	42.75	23.4
85	44.83	22.3
88	48.05	20.8
90	50.26	19.9
93	53.67	18.6
95	56.00	17.9
98	59.59	16.8
100	62.05	16.1
105	68.41	14.6
106	69.72	14.3
110	75.08	13.3
115	82.06	12.2
120	89.35	11.2
125	96.95	10.3

Density 7.90 g/cm³, diameter squared x 0.006205. Sizes are the published range at the nominal diameters shown.

Ordering AISI 310S hot rolled round bar

An enquiry for this grade in this form states the grade and the governing standard, for example AISI 310S to ASTM A276 or EN 10088-3, the solution annealed condition, the diameter with the tolerance to ASTM A484 or EN 10060, the surface as black, spot ground or fully ground, the cut length, the quantity, the test certificate type to EN 10204, and any test called for, such as ultrasonic testing or PMI. Laxcon Steels rolls the bar to order.