21 RW
What is the nominal o.d. (mm) for 21 RW?
For 21 RW, nominal o.d. (mm) is 0.81; nominal i.d. (mm) is 0.51; wall thickness (mm) is .152, verified against its source on 2026-08-27.
21 RW 0.81 0.81/0.83 .152 0.51 0.50/0.53
— nesmalltube.com, retrieved 2026-08-27
- Gauge number
- 21 RW verified
- Nominal O.D. (mm)
- 0.81 verified
- Nominal I.D. (mm)
- 0.51 verified
- Wall thickness (mm)
- .152 verified
Source
- nesmalltube.comhttps://nesmalltube.com/wp-content/uploads/2025/06/Metric_Chart_Web.pdf