Threaded Round Head Plugs are used to close female threaded ends of threaded piping components such as threaded valves, threaded full couplings, threaded half couplings, mostly for drain and vent points on threaded piping systems. As per ASME B16.11 : Forged Fittings, Socket Welding and Threaded, available size range is 1/8″ to 4″, though they are used mostly in piping sizes upto 1.5″ only. This page provides inch dimensions for these fittings.
Available Dimensions are: A: Length (Minimum), H | Hex Head (Minimum), F : Width of Flats (Nominal).

| NPS | A | D | E |
|---|---|---|---|
| 1/8 | 10 | 35 | 10 |
| 1/4 | 11 | 41 | 14 |
| 3/8 | 13 | 41 | 18 |
| 1/2 | 14 | 44 | 21 |
| 3/4 | 16 | 44 | 27 |
| 1 | 19 | 51 | 33 |
| 1-1/4 | 21 | 51 | 43 |
| 1-1/2 | 21 | 51 | 48 |
| 2 | 22 | 64 | 60 |
| 2-1/2 | 27 | 70 | 73 |
| 3 | 28 | 70 | 89 |
| 4 | 32 | 76 | 114 |
| NPS | A | D | E |
General Notes
Dimensions are in inches

