Bought for high-volume machining on automatic screw machines: bushings, shafts, couplings, fittings, valve and fastener parts whose cost is set by machining time and whose environment is dry or mildly corrosive. The selection criterion is machinability, not corrosion resistance;<\/div>\n<\/div>\n
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Forms<\/div>\n
Round bar \u00b7 flat bar \u00b7 plate \u00b7 sheet \u00b7 pipe and tube \u00b7 forging. All forms supplied to order. WARNING: the specification base of 303 is BAR and FORGING STOCK (ASTM A582, A484, A314). ISSF\/worldstainless and AZoM state that 303 is not produced in flat-rolled products and that its mechanical properties are specified for long products (bar) in ASTM A582; no current ASTM product specification for 303 in plate, sheet or pipe could be confirmed by four sources.<\/div>\n<\/div>\n
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Standards<\/div>\n
AMS 5640<\/b> (bars, wire, mechanical tubing and forgings; Type 1 = S30300 sulphur 303, Type 2 = S30323 selenium 303Se) \u00b7 AMS 5738<\/b> (303Se, Condition B high tensile). ASTM: A582 \/ A582M (Free-Machining Stainless Steel Bars \u2014 the PRIMARY specification for 303, Condition A) \u00b7 A484 (general requirements for bars, billets and forgings) \u00b7 A314 (billets and bars for forging) \u00b7 A320 Gr B8F (bolting). EN: 10088-3 (1.4305).
1) 303 IS OUTSIDE THE SCOPE OF ASTM A276. The scope text of A276\/A276M states in Note 2 that free-machining stainless bars belong to A582\/A582M; the A276 grade tables published by Ferrobend and Boltport likewise contain neither S30300 nor S30323.<\/span><\/div>\n<\/div>\n\n
Advantage<\/div>\n
Machinability. AZoM calls 303 ‘the optimum in machinability among the austenitic stainless steels’ and gives the rating as about 78% of the free-machining reference steel B1212; MW Alloys gives the same quantity as 85% against the 1215 reference.<\/div>\n<\/div>\n
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Welding<\/div>\n
IT IS NOT WELDED \u2014 this is the defining limit of the grade. Sandmeyer says it is ‘not recommended for applications requiring welding’; ISSF\/worldstainless and AZoM say ‘not generally recommended’; thyssenkrupp says ‘the sulphur addition results in poor weldability’;<\/div>\n<\/div>\n
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Limits<\/div>\n
1) IT IS NOT WELDED (five sources above). If a welded structure is required, 304\/316 is chosen rather than 303; even on single parts, if there is a weld bead the grade should be struck from the specification. 2) CORROSION RESISTANCE IS LOWER THAN 304.<\/div>\n<\/div>\n