API Spec 20F

This specification specifies requirements for the qualification, production and documentation of corrosion resistant bolting used in the petroleum and natural gas industries.

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

This specification establishes requirements for two bolting specification levels (BSL). These two BSL designations define different levels of technical, quality and qualification requirements. The levels are designated as BSL-2 and BSL-3. BSL-2 includes requirements in addition to those stated in the ASTM A453 and API 6A718. BSL-3 adds technical, quality and qualification criteria to BSL-2. BSL-2 and BSL-3 are intended to be comparable to BSL-2 and BSL-3 as found in API 20E. BSL-1 is omitted from this standard.

This specification covers the following product forms, processes, and sizes:

a) machined studs;
b) machined bolts, screws and nuts;
c) cold headed bolts, screws and nuts;
d) hot formed bolts and screws e) hot formed bolts and screws ≥1.5 in. (38.1 mm) nominal diameter;
f) roll threaded studs, bolts, and screws g) roll threaded studs, bolts, and screws ≥1.5 in. (38.1 mm) diameter;
h) hot formed nuts i) hot formed nuts ≥1.5 in. (38.1 mm) nominal diameter.