API SPEC7-2 pdf download Threading and Gauging of Rotary Shouldered Connections
4 General Information
In this standard , data are expressed in both the International System (SI) 01 units and the U.S. customary (USC) system of units. Separate tables for data expressed in SI units and USC units are given in Annex B and Annex C , respectively. Figures express data in both SI and USC units. For a specific order item , it is intended that only one system of units be used , without combining data expressed in the other system.
Products manu1 actured to specifications expressed in either 01 these unit systems shall be considered equivalent and totally interchangeable. Consequently , compliance with the requirements 01 this standard as expressed in one system provides compliance with requirements expressed in the other system. Some of the dimensions in USC units have been converted 1rom traditional fractional measurements. Depending on the rounding conventions used , tabulated dimensions andlor tolerances may differ by up to 0.002 in. from some existing manufacturing documents. These differences are to be considered acceptable andin compliance and shall not be cause of rejection. See Annex D for guidance on unit conversion and rounding.NOTE Any style of rotary shouldered connection can be made in right-hand (RH) or left-hand (LH) versions; right-handis assumed unless otherwise designated as LH; left-hand threads are not supported by the international system ofgauges and calibration,except in the REG style.
4.2Purchaser Supplied lnformation
ln placing orders for equipment to be manufactured with rotary shouldered connections in accordance withthis standard, the purchaser shall specify the following on the purchase order:
a)number of this standard;
b)thread style and size; and
c)if necessary，supplementary requirements as detailed in Section 6，which are optional with the
5.1Thread Profile and Dimensions5.1.1Overall Dimensions
Rotary shouldered connections shall be furnished in the sizes and styles shown in Figures 1 and 2 andTable B.1. Dimensions of rotary shouldered connections shall conform to Table B.1,with the thread formsdefined in Table B.2.The dimensions shown in Tables B.1 and B.2 that have no specified tolerance and donot have tolerances defined below，shall be considered reference dimensions. Deviations from thesedimensions shall not be cause for rejection. The extent of the bevel of the small end of the pin is optional withthe manufacturer.
Right-hand threads shall be considered standard. Left-hand threads may be made using this standard, buttraceable gauging following this standard exists only in the REG style.
5.1.2 Pin Dimensions
The pin dimensions in Table B.1 shall be interpreted using Figures 1 and 188.8.131.52 Pin Base Diameter
Pin base diameter dimensional requirements shall be as follows.
Rotary shouldered connections on drill collars shall have a cylindrical region at the base conforming to thedimension De of Table B.1 and shall have a radius Re 1.6 mm ±0.4 mm (0.063 in. 0.016 in.) at the pinbase as shown in Figure 2, except when a stress-relief groove is used.
This feature reduces the stress concentration factor in this area.Rotary shouldered connections on productsother than drill collars, such as tool joints, may have a tapered region at the pin base rather than a cylindricalregion. ln this case the radius at the intersection of the taper and the sealing face shall be0.78 mm 10.12 mm (0.031 in. 10.005 in.), as shown in Figure 2.
The distance between the pin shoulder and the intersection of the pin base diameter or thread major conewith the thread flank at the first point of full thread depth shall not exceed Ln (see Figure 2).