For induction or direct resistance heat treatment, calibration shall be in accordance with the manufacture’s written procedure.ĪSTM A320 Grade L43 and ASTM A540, Grade B23 shall be double tempered. Furnace calibration shall be in accordance with API 6A, Annex M, SAE AMS 2750 or SAE AMS-H-6875. Unified National Threads shall be 'R' (UNR controlled radius root) series. Manufacturing processes shall be performed so as to avoid the introduction of stress risers that can occur from sharp angles and tool marks. (38.1 mm) nominal diameter.ĪPI 20E Bolting Materials Material DesignationĪPI 20E Bolting Heat Treatment requirements BSL1 Requirements

Roll threaded studs, bolts, and screws ≥1.5 in.

Roll threaded studs, bolts, and screws <1.5 in.

Cold formed bolts, screws, and nuts with cut or cold formed threads (BSL-1 only).The following paragraphs describe the conditions which, when met, allow the bolting to meet the appropriate bolting type and BSL classification level. Qualification to a higher BSL shall qualify to a lower BSL.

Each individual bolting type shall be qualified. The manufacturer may qualify to one or more of the bolting types listed in 1.4 and to one or more BSLs. API 20E standard states the requirements for three bolting specification levels (BSL) and nine bolting types. Fasteners, Stud Bolts, Studs, Bolting, Screws, Nuts, WashersĪPI 20E standard specifies requirements for the qualification, production and documentation of Alloy and Carbon Steel Bolting for Use in the Petroleum and Natural Gas Industries.

Api 20e code book pdf