If its ASTM A238 (Specification for Forgings, Alloy Steel, for Railway Use), it was withdrawn and replaced with ASTM A730 (Standard Specification for Forgings, Carbon and Alloy Steel, for Railway Use) which has also been withdrawn (in 2004) and replaced with A668/A668M-04 (Standard Specification for Steel Forgings, Carbon and Alloy, for General Industrial Use) The following summary is off the ASTM website (the actual document which probably gives you the values you are looking for is about $40 (US). Join ASTM and you can download the pdf's whenever you need them: 1. Scope 1.1 This specification covers untreated and heat-treated carbon and alloy steel forgings for general industrial use. Other ASTM specifications for forgings are available for specific applications such as pressure vessels, railroad use, turbine generators, gearing, and others involving special temperature requirements. 1.2 Hot-rolled or cold finished bars are not within the scope of this specification. 1.3 Six classes of carbon steel and seven classes of alloy steel forgings are listed (see Section ) , which indicates their required heat treatments, as well as mechanical properties. 1.4 Provision, with the suffix H for certification and marking, for the supply of forgings after hardness testing only. 1.5 Supplementary requirements, including those in Specification A 788, of an optional nature are provided. These shall apply only when specified by the purchaser. 1.6 lists the current classes corresponding to the various classes of Specifications A 235, A 237, and A 243, which have been superseded by this specification. 1.7 The values stated in either inch-pound units or SI units are to be regarded separately as the standard; within the text and tables, the SI units are shown in brackets. The values stated in each system are not exactly equivalent; therefore; each system must be used independently of the other. Combining values from the two systems may result in nonconformance with the specification. 1.8 Unless the order specifies the applicable "M" specification, the forgings shall be furnished to the inch-pound units A 370 Test Methods and Definitions for Mechanical Testing of Steel Products A 275/A 275M Test Method for Magnetic Particle Examination of Steel Forgings A 388/A 388M Practice for Ultrasonic Examination of Heavy Steel Forgings E 381 Method of Macroetch Testing Steel Bars, Billets, Blooms, and Forgings A 788 Specification for Steel Forgings, General Requirements ----------------------------------------------------------- Index Terms alloy steel forgings; carbon steel forgings; general industrial applications; heat treatment classifications; strength classifications; 77.140.851Thanks, but it is A283. I found the spec - its Ft is 55 ksi, its Fy is 30 ksi.Additional stuff to know Mild steel, very weldable. Very low toughness, Transition temps about 50 usually. Most common material for tank construction during 1960s and 1970s. Not produced on regular basis. Easier to obtain A36 now. Steve Braune Tank Industry Consultants tankindustryManufacturer: ChevroletSeller Rating: 100.0% positive