scope:

This specification covers the chemical and mechanical requirements of hexagon and square-head zinc-coated steel bolts and atmospheric corrosion-resistant bolts, in nominal thread diameters of ½ ⅝, ¾, ⅞ and 1 in. for use in the construction of transmission towers, substations, and similar steel structures. The various types of bolts covered in this specification are:

Type 0 - Zinc-coated bolts made of low or medium carbon steel.

Type 1 - Zinc-coated bolts made of medium carbon steel, quenched and tempered.

Type 2 - Zinc-coated bolts made from what is generally described as low-carbon martensite steel, quenched and tempered.

Type 3 - Bare (uncoated), quenched and tempered bolts made of steel having atmospheric corrosion-resistance and weathering characteristics comparable to that of the steel covered in Specifications A 242/A 242M, A 588/A 588M, and A 709/A 709M. The atmospheric corrosion resistance of these steels is substantially better than that of carbon steel with or without copper addition (see 5.4). When properly exposed to the atmosphere, these steels can be used bare (uncoated) for many applications.

For applications requiring improved low-temperature characteristics, use of Types 1, 2, or 3 bolts is recommended.

Annex A1 of this specification covers zinc-coated steel ladder bolts, step bolts, and support-equipment bolts.

Unless otherwise specified, all nuts used on these bolts shall be hex style and conform to the requirements of Specification A 563 as follows:

Suitable washers for use with Type 0 are zinc-coated carbon-steel washers with dimensions that are in accordance with Specification F 436. Suitable washers for use with Type 1 and Type 2 bolts are zinc-coated Type 1 hardened-steel washers that are in accordance with Specification F 436. Suitable washers for use with Type 3 bolts are Type 3 hardened-steel washers that are in accordance with Specification F 436.

Nuts and washers that are supplied under this specification that are zinc coated shall be in accordance with 4.4.

The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are for information only.