【国外标准】 Standard Specification for Seamless Cold-Drawn Carbon Steel Tubing for Hydraulic System Service

This specification covers nominal thickness, seamless, cold-drawn carbon steel tubing intended for use in hydraulic systems and in other similar applications where forming operations require tight radius bending and flaring. The tubes shall be made by the seamless process and shall be cold drawn to size. Heat treatment shall be made to the tube samples after the final cold working operation. Finished tubes shall be free of scale but may have a superficial oxide film on the surfaces. Removal of surface imperfections, such as handling marks, straightening marks, light mandrel and die marks, shallow pits, and scale pattern, will not be required provided they are within the allowable tolerances. Finished tubes shall be protected both on the outside and the inside diameter to prevent corrosion in transit. Each lot of tubes shall be subjected to the following tests: tension test, flaring test, flattening test, hardness test, and hydrostatic proof test.1.1 This specification covers nominal wall thickness, seamless, cold-drawn carbon steel tubing intended for use in hydraulic systems and in other similar applications where forming operations require tight radius bending and flaring.1.2 Tubing sizes and thicknesses usually furnished to this specification are 1/8 to 31/2 in. [3.2 to 88.9 mm] in outside diameter and 0.035 to 0.134 in. [0.9 to 3.4 mm] inclusive, in nominal wall thickness. Tubing having other dimensions may be furnished, provided such tubing complies with all other requirements of this specification.1.3 Mechanical property requirements do not apply to tubing smaller than 1/8 in. [3.2 mm] in inside diameter or 0.015 in. [0.4 mm] in thickness.1.4 Optional supplementary requirements are provided and, when desired, shall be so stated in the order.1.5 The values stated in either SI units or inch-pound units are to be regarded separately as standard. Within the text, the SI units are shown in brackets. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.