Reference Source

18 RW

What is the nominal o.d. (mm) for 18 RW?

For 18 RW, nominal o.d. (mm) is 1.27; nominal i.d. (mm) is 0.84; wall thickness (mm) is .216, verified against its source on 2026-08-27.

18 RW 1.27 1.26/1.28 .216 0.84 0.80/0.88

nesmalltube.com, retrieved 2026-08-27

Gauge number
18 RW verified
Nominal O.D. (mm)
1.27 verified
Nominal I.D. (mm)
0.84 verified
Wall thickness (mm)
.216 verified
Sourcenesmalltube.com
Verified
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DatasetHypodermic needle gauge dimensions (OD, ID, wall thickness, dead volume)

Source

Last verified against source: . Due for re-check by . This page as Markdown · OKF bundle · full dataset as JSON.