NPS 1/8 Pipe Nipple, ASTM A733
The NPS 1/8 pipe nipple (ASTM A733) joins two NPS 1/8 NPT fittings: Schedule 40 pipe 10.287 mm across with a 1.7272 mm wall, threaded 27 threads per inch at both ends. It comes in 17 lengths from 19.05 to 304.8 mm, each as simplified and threaded STEP.

How these parts are made, and what the levels mean: read the method
- Also searched as: NPS 1/8 pipe nipple, NPS 1/8 x 19.05 to NPS 1/8 x 304.8 pipe nipples
- Model id:
astm-a733-nps1-8
- Standard: ASTM A733 · NPS 1/8, pitch 0.941 mm, NPT taper pipe thread (ASME B1.20.1), 60 degree profile, 1:16 taper, right hand
Lengths
Dimensions

| Symbol | Name | min | nom | max | Modeled | Rule | Level |
|---|
| l_close_in | Close nipple length, inches | | 0.75 | | 0.75 | nominal | L1 |
| l_close | Close nipple length | | 19.05 | | 19.05 | nominal | L1 |
| D | Outside diameter | | 10.287 | | 10.287 | nominal | L1 |
| T | Wall thickness | | 1.7272 | | 1.7272 | nominal | L1 |
| D_in | Outside diameter, inches | | 0.405 | | 0.405 | nominal | L1 |
| T_in | Wall thickness, inches | | 0.068 | | 0.068 | nominal | L1 |
| n | Threads per inch | | 27 | | 27 | nominal | L1 |
| P | Pitch | | 0.03703704 | | 0.03703704 | nominal | L1 |
| D | Outside diameter of pipe | | 0.405 | | 0.405 | nominal | L1 |
| E0 | Pitch diameter at the small end | | 0.36351 | | 0.36351 | nominal | L1 |
| L1 | Hand-tight engagement length | | 0.1615 | | 0.1615 | nominal | L1 |
| E1 | Pitch diameter at the hand-tight plane | | 0.3736 | | 0.3736 | nominal | L1 |
| L2 | Effective thread length | | 0.2639 | | 0.2639 | nominal | L1 |
| E2 | Pitch diameter at the end of the effective thread | | 0.38 | | 0.38 | nominal | L1 |
| L4 | Overall length of external thread | | 0.3924 | | 0.3924 | nominal | L1 |
| h | Height of thread | | 0.02963 | | 0.02963 | nominal | L1 |
| K0 | Basic minor diameter at the small end | | 0.3339 | | 0.3339 | nominal | L1 |
| alpha | Flank angle | | 60 | | 60 | nominal | L1 |
| taper | Taper | | 16 | | 16 | nominal | L1 |
Drawing

As a PDF: CC-ASTMA733-SZ-1-8.pdf.
The NPS 1/8 pipe nipple beside the NPS 1/4
The NPS 1/8 is the first of the 9 ASTM A733 pipe nipples published here, listed from NPS 1/8 to NPS 2.
- Close nipple length, inches (l_close_in): 0.75 mm on the NPS 1/8 pipe nipple, against 0.875 mm on the NPS 1/4.
- Close nipple length (l_close): 19.05 mm on the NPS 1/8 pipe nipple, against 22.225 mm on the NPS 1/4.
- Outside diameter (D): 10.287 mm on the NPS 1/8 pipe nipple, against 13.716 mm on the NPS 1/4.
- Wall thickness (T): 1.7272 mm on the NPS 1/8 pipe nipple, against 2.2352 mm on the NPS 1/4.
- Outside diameter, inches (D_in): 0.405 mm on the NPS 1/8 pipe nipple, against 0.54 mm on the NPS 1/4.
- Wall thickness, inches (T_in): 0.068 mm on the NPS 1/8 pipe nipple, against 0.088 mm on the NPS 1/4.
- Threads per inch (n): 27 mm on the NPS 1/8 pipe nipple, against 18 mm on the NPS 1/4.
- Pitch (P): 0.03703704 mm on the NPS 1/8 pipe nipple, against 0.05555555 mm on the NPS 1/4.
Other sizes
Documents
Sources
anvil-a733-nipples, engineersedge-npt, engineersedge-npt-basic, etb-b36-10, etb-npt, smithcooper-a733-nipples, steeltube-b36-10, ultimatewasher-npt, wikipedia-npt. Full citations: the method page and this size's datasheet.
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