ASTM F876/F877 (CTS) ·size chart
CTS 2 PEX outer diameter: 2.125 in / 53.975 mm
- OD (inches)
- 2.125 in
- OD (millimetres)
- 53.975 mm
- DN
- 50
- Wall
- not published
- Bore
- not published
Crosslinked polyethylene tubing in CTS (copper tube size) ODs, designated by SDR rather than schedule. For CTS 2 we can publish the outside, but no wall yet — the wall values in our sources did not reach two independent confirmations, so we are not guessing the bore.
| Nominal | DN | OD (in) | OD (mm) | Wall series published |
|---|---|---|---|---|
| 2 | 50 | 2.125 | 53.975 | none — 1 designation(s) awaiting a second source |
Why the wall is missing. 1 designation(s) (9) appear in at least one source for this size, but not two independent ones. Unverified values are kept out of the published set on purpose — the rule.
Same body, different material. steel 2 Sch 40 = STD, and PVC 2 Sch 40, and stainless 2 Sch 40S are the same 0.154 in wall on the same 2.375 in / 60.325 mm body; steel 2 Sch 80 = XS, and PVC 2 Sch 80, and stainless 2 Sch 80S are the same 0.218 in wall on the same 2.375 in / 60.325 mm body. A caliper cannot separate them — what the pipe is made of does.
The same nominal label in other standards
| Standard | OD (in) | OD (mm) | DN | Published wall series |
|---|---|---|---|---|
| ASME B36.10M · welded and seamless steel pipe | 2.375 | 60.325 | 50 | Sch 10 0.109 · Sch 40 0.154 · Sch 80 0.218 · Sch 160 0.344 · STD 0.154 · XS 0.218 · XXS 0.436 |
| ASTM D2241 · PVC pressure pipe | 2.375 | 60.325 | 50 | Sch 40 0.154 · Sch 80 0.218 |
| ASTM F876/F877 (CTS) · PEX tubing | 2.125 | 53.975 | 50 | no wall published yet (1 awaiting a second source) |
| ASME B36.19M · stainless steel pipe | 2.375 | 60.325 | 50 | Sch 5S 0.065 · Sch 10S 0.109 · Sch 40S 0.154 · Sch 80S 0.218 |
PEX vs steel — 2 (ASME B36.10M) · PEX vs PVC — 2 (ASTM D2241)
Measuring this size
- Measure across the pipe, not the fitting: that is the OD, and it is the number a clamp, a hole saw or an insulation sleeve has to match.
- Measured
53.975± a fraction of a millimetre points at CTS 2. Check which standards a measurement fits — the same OD can belong to more than one. - The bore decides flow; the wall decides pressure rating and how deep a thread cuts. Neither number is in the name CTS 2 carries.
Questions about CTS 2
What is the outer diameter of CTS 2 pipe?
2.125 in / 53.975 mm — but that is only true for ASTM F876/F877 (CTS). The same nominal label in ASME B36.10M (2.375 in / 60.325 mm) and ASTM D2241 (2.375 in / 60.325 mm) and ASME B36.19M (2.375 in / 60.325 mm) is a different pipe. Calipers measure this number; the name does not.
Is CTS 2 the same as DN 50?
DN 50 is the millimetre-family name for this size, so yes for the size — no for the number. DN is not the outer diameter and not the bore; CTS 2 measures 2.125 in / 53.975 mm outside. See the NPS ↔ DN table for the whole series.
No edition year is claimed. These values match ASTM F876/F877 (CTS) as published by the sources above, but the specific printing was not verified, so the standard is named without a year.
Next
- Full ASTM F876/F877 (CTS) chart (9 sizes)
- OD / ID / wall calculator — measure two, get the third
- About ASTM F876/F877 (CTS)