Hollow Hex Plug (Male NPT Thread)
| Male NPTThread Size | Dimensions in mm | F-Hex(Inch) | Dawsons-TechPart No. |
| P | L | ||
| 1/8 | 10.4 | 3/16 | HHP-2N |
| 1/4 | 15.0 | 1/4 | HHP-4N |
| 3/8 | 15.0 | 5/16 | HHP-6N |
| 1/2 | 19.3 | 3/8 | HHP-8N |
Hollow Hex Plug (Male ISO Tapered (BSPT) Thread)
| Male BSPTThread Size | Dimensions in mm | F-Hex(Inch) | Dawsons-TechPart No. |
| P | L | ||
| 1/8 | 10.4 | 3/16 | HHP-2RT |
| 1/4 | 15.0 | 1/4 | HHP-4RT |
| 3/8 | 15.0 | 5/16 | HHP-6RT |
| 1/2 | 19.3 | 3/8 | HHP-8RT |