This specification covers five grades of zinc-5 % aluminum-mischmetal (Zn-5 Al-MM) alloy-coated, steel wire strand, composed of a number of round, steel wires, with four weights of Zn-5 Al-MM alloy coatings, suitable for use as guys, messengers, span wires, and for similar purposes. The five grades covered are: utilities; common; Siemens-Martin; high-strength; and extra high-strength. The four weights covered here are Classes 1, A, B, and C. The base metal shall be steel made by any commercially accepted steel making process. The bath metal used in continuous hot-dip Zn-5 Al-MM alloy-coating shall meet the chemical composition limits specified. The determination of chemical composition shall be made in accordance to the required specifications. Breaking strength test, elongation test, and ductility test shall be made to conform to the requirements specified.

1.1 This specification covers five grades of zinc-5 % aluminum-mischmetal (Zn-5 Al-MM) alloy-coated, steel wire strand, composed of a number of round, steel wires, with four weights of Zn-5 Al-MM alloy coatings, suitable for use as guys, messengers, span wires, and for similar purposes. The product is intended for applications requiring corrosion resistance and formability.

1.2 The five grades covered are as follows:

1.2.1 Utilities,

1.2.2 Common,

1.2.3 Siemens-Martin,

1.2.4 High-strength, and

1.2.5 Extra high-strength,

1.2.6 Minimum breaking strengths of strand for each grade are described in Section 7.

1.3 The four weights of coatings are: Class1 and Classes A, B, and C. Minimum weights of Zn-5 Al-MM alloy are described in Section 10.

1.4 This specification is applicable to orders in either inch-pound units (as A 855) or acceptable SI units (as A 855M). Inch-pound units and SI units are not necessarily equivalent.