Standard Specification for Steel Transmission Tower Bolts, Zinc-Coated and Bare
|Publication Date:||15 February 1993|
|ICS Code (Bolts, screws, studs):||21.060.10|
|ICS Code (Power transmission and distribution lines):||29.240.20|
1.1 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:
1.1.1 Type 0--Zinc-coated bolts made of low or medium carbon steel.
1.1.2 Type 1--Zinc-coated bolts made of medium carbon steel, quenched and tempered.
1.1.3 Type 2--Zinc-coated bolts made from what is generally described as low-carbon martensite steel, quenched and tempered.
1.1.4 Type 3--Bare (uncoated), quenched and tempered bolts made of steel having atmospheric corrosion-resistance
1.1.5 For applications requiring improved low-temperature characteristics, use of Types 1, 2, or 3 bolts is recommended.
1.2 Annex A1 of this specification covers zinc-coated steel ladder bolts, step bolts, and support-equipment bolts.
1.3 Unless otherwise specified, all nuts used on these bolts shall be hex style and conform to the requirements of Specification A 563 as follows:
1.4 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.
1.5 Nuts and washers that are supplied under this specification that are zinc coated shall be in accordance with 4.4.
1.6 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are for information only.