scope:

Purpose

This standard specifies requirements for the qualification, production, and documentation of alloy and carbon steel bolting used in the petroleum and natural gas industries.

Applicability

This standard applies when referenced by an applicable API equipment standard or otherwise specified as a requirement for compliance.

Bolting Specification Levels

This standard establishes requirements for three bolting specification levels (BSLs). These three BSL designations define different levels of technical, quality, and qualification requirements, BSL-1, BSL-2, and BSL-3. The BSLs are numbered in increasing levels of requirements in order to reflect increasing technical, quality, and qualification criteria.

Bolting Types

This standard covers the following finished product forms, processes, and sizes:

a) machined studs;

b) machined bolts, screws, and nuts;

c) cold formed bolts, screws, and nuts with cut or cold formed threads (BSL-1 only);

d) hot formed bolts and screws <1.5 in. (38.1 mm) nominal diameter;

e) hot formed bolts and screws ≥1.5 in. (38.1 mm) nominal diameter;

f) roll threaded studs, bolts, and screws <1.5 in. (38.1 mm) diameter;

g) roll threaded studs, bolts, and screws ≥1.5 in. (38.1 mm) diameter;

h) hot formed nuts <1.5 in. (38.1 mm) nominal diameter;

i) hot formed nuts ≥1.5 in. (38.1 mm) nominal diameter.

NOTE Alternate geometry components made in accordance with this specification may be specified by the purchaser.