API Numbered Rotary Shouldered Connections
| Conn** No | Thread form, Inch radius | Threads per inch | Taper Inches per foot on Dia | Pitch Dia of Thread at Gage Point C | Large Dia of Pin Reference D1 | Flat on Pin D 1/64 | Small Dia of Pin. D2 | Depth of Box L1 +0 | Length of Pin L2 +.04 | Box Counter Bore C2 |
|---|---|---|---|---|---|---|---|---|---|---|
| 23 | 0.038R | 4 | 2 | 2.355 | 2.563 | 2.437 | 2.063 | 3 5/8 | 3 | 2 3/8 |
| 26** | 0.038R | 4 | 2 | 2.668 | 2.876 | 2.750 | 2.376 | 3 5/8 | 3 | 2 15/16 |
| 31** | 0.038R | 4 | 2 | 3.183 | 3.391 | 3.266 | 2.808 | 4 1/8 | 3 1/2 | 3 22/32 |
| 35 | 0.038R | 4 | 2 | 3.631 | 3.739 | 3.625 | 3.114 | 4 2/8 | 3 3/4 | 3 13/16 |
| 38** | 0.038R | 4 | 2 | 3.808 | 4.016 | 3.891 | 3.349 | 4 5/8 | 4 | 4 16/34 |
| 40** | 0.038R | 4 | 2 | 4.072 | 4.280 | 4.156 | 3.530 | 5 1/8 | 4 1/2 | 4 11/32 |
| 44 | 0.038R | 4 | 2 | 4.417 | 4.625 | 4.499 | 3.875 | 5 1/8 | 4 1/2 | 4 11/18 |
| 46** | 0.038R | 4 | 2 | 4.626 | 4.834 | 4.709 | 4.084 | 5 1/8 | 4 1/2 | 4 22/32 |
| 50** | 0.038R | 4 | 2 | 5.0417 | 5.250 | 5.125 | 4.500 | 5 1/8 | 4 1/2 | 5 5/16 |
| 56 | 0.038R | 4 | 3 | 5.616 | 5.876 | 5.703 | 4.626 | 5 5/8 | 5 | 5 15/16 |
| 61 | 0.038R | 4 | 3 | 6.178 | 6.438 | 6.266 | 5.063 | 6 1/8 | 5 1/2 | 6 1/2 |
| 70 | 0.038R | 4 | 3 | 7.053 | 7.313 | 7.141 | 5.813 | 6 5/8 | 6 | 7 3/8 |
| 77 | 0.038R | 4 | 3 | 7.741 | 8.000 | 7.828 | 6.376 | 7 1/8 | 6 1/2 | 8 1/16 |
**The connection number is the diameter of the connection at the gage point rounded to units and tenths of inches.
*See Table 12 for interchangeability of numbered rotary shouldered connections with rotary shouldered connections of Table 9.1
Interchangeability of Numbered Rotary Shouldered Connections with Rotary Shouldered Connections of Table 9.1
| Numbered Connection | Equivalent Connection of Table 9.1 |
|---|---|
| 26 | 2 3/8 IF |
| 31 | 2 7/5 IF |
| 38 | 3 1/2 IF |
| 40 | 4 FH |
| 46 | 4 IF |
| 50 | 4 1/2 IF |
