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Designation: A 194/A 194M – 98b
AMERICAN SOCIETY FOR TESTING AND MATERIALS 100 Barr Harbor Dr., West Conshohocken, PA 19428 Reprinted from the Annual Book of ASTM Standards. Copyright ASTM

An American National Standard Endorsed by Manufacturers Standardization Society of the Valve and Fittings Industry Used in USNRC-RDT Standards

Standard Specification for

Carbon and Alloy Steel Nuts forBolts for High Pressure or High Temperature Service, or Both1
This standard is issued under the fixed designation A 194/A 194M; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript epsilon (e) indicates an editorial change sincethe last revision or reapproval. This standard has been approved for use by agencies of the Department of Defense.

1. Scope 1.1 This specification2 covers a variety of carbon, alloy, and martensitic stainless steel nuts in the size range 1⁄4 through 4 in. and metric M6 through M100 nominal. It also covers austenitic stainless steel nuts in the size range 1⁄4 in. and M6 nominal and above. Thesenuts are intended for high-pressure or hightemperature service or both. Grade substitutions without the purchaser’s permission are not allowed. 1.2 Bars from which the nuts are made shall be hot-wrought. The material may be further processed by centerless grinding or by cold drawing. Austenitic stainless steel may be solution annealed or annealed and strain-hardened. When annealed and strainhardened austenitic stainless steel is ordered in accordance with Supplementary Requirement S1, the purchaser should take special care to ensure that 7.2.2, Supplementary Requirement S1, and Appendix X1 are thoroughly understood. 1.3 Supplementary requirements (S1 through S5) of an optional nature are provided. These shall apply only when specified in the inquiry, contract, and order. 1.4 Thisspecification is expressed in both inch-pound units and in SI units. However, unless the order specifies the applicable“ M” specification designation (SI units), the material shall be furnished to inch-pound units. 1.5 The values stated in either inch-pound units or SI units are to be regarded separately as standard. Within the text, the SI units are shown in brackets. The values stated in each system are notexact equivalents; therefore, each system must be used independently of the other. Combining values from the two systems may result in noncomformance with the specification.
NOTE 1—Grade 2M has been replaced with Grade 2HM. During a transition period both grade markings are acceptable.

2. Referenced Documents 2.1 ASTM Standards: A 29/A 29M Specification for Steel Bars, Carbon and Alloy, Hot-Wroughtand Cold-Finished, General Requirements for3 A 153 Specification for Zinc Coating (Hot-Dip) on Iron and Steel Hardware4 A 165 Specification for Electrodeposited Coatings of Cadmium on Steel5 A 276 Specification for Stainless Steel Bars and Shapes3 A 320/A 320M Specification for Alloy-Steel Bolting Materials for Low-Temperature Service6 A 370 Test Methods and Definitions for Mechanical Testing of SteelProducts7 A 484/A 484M Specification for General Requirements for Stainless and Heat-Resisting Bars and Shapes, Carbon, Rolled from “T” Rails3 A 751 Test Methods, Practices, and Terminology for Chemical Analysis of Steel Products7 A 788 Specification for Steel Forgings, General Requirements3 B 633 Specification for Electrodeposited Coatings of Zinc on Iron and Steel5 B 695 Specification for Coatingsof Zinc Mechanically Deposited on Iron and Steel5 B 696 Specification for Coatings of Cadmium Mechanically Deposited5 E 18 Test Methods for Rockwell Hardness and Rockwell Superficial Hardness of Metallic Materials8 E 381 Method of Macroetch Testing Steel Bars, Billets, Blooms, and Forgings8 2.2 American National Standards:9 B 1.1 Unified Screw Threads
Annual Book of ASTM Standards, Vol 01.05....