Nylon tubing sizes: inch (1/8 to 5/8 in OD) and metric (3 to 12 mm) OD × ID × wall, standard, D.O.T. and high-pressure nylon 11 — dimension sheet Source: Xem Studio, https://xemstudio.com/objects/nylon-tubing-inch-metric-sizes/ (sheet CC BY 4.0) Basis: Freelin-Wade nylon tubing datasheet (standard nylon inch and metric, D.O.T. nylon 11, high-pressure nylon 11); one maker; numbers only; pressure ratings left out on purpose Catalog version: 2026-10-20 Sizes: see table below - Nylon (polyamide) tubing is sold by OD, with the ID set by the wall: 1/4 in OD comes with three walls, 0.035 in (ID 0.180), 0.040 in (ID 0.170) and 0.062 in (ID 0.125) in the standard line, so '1/4 in nylon tubing' is not one size and the fitting must match the OD. Freelin-Wade's inch sizes are 1/8, 5/32, 3/16, 1/4, 5/16, 3/8, 1/2 and 5/8 in OD; the metric sizes are 3, 4, 5, 6, 8, 10 and 12 mm OD with 1 mm walls from 5 mm up (6 × 4 mm, 8 × 6 mm, 10 × 8 mm, 12 × 10 mm). - Each maker has its own families: 'standard nylon', 'D.O.T. nylon 11' (air-brake tubing, OD and wall only, no ID printed; the ID shown is OD − 2 × wall) and 'high-pressure nylon 11' (thicker walls, smaller IDs). Millimetres are inch × 25.4; metric inches are mm ÷ 25.4. Each ID and wall was checked against OD − 2 × wall: all agree to within 0.004 in for the inch rows and 0.1 mm for the metric rows. - Bend radius is shown (inches, as printed) for the standard inch line only; the metric bend radii in the datasheet are printed without units and are not copied. Working pressures at 75 °F and 150 °F, burst pressures and part numbers are left out. One more table in the datasheet (six sizes, 1/8 to 1/2 in, with a lighter pressure rating) has no heading in the text read and is not used; the datasheet also names a 'super soft' nylon 11 with no size table. - Push-to-connect fittings take tube by OD: push-to-connect-fitting-sizes. Silicone and PU tube: silicone-tube-and-fittings; PTFE: ptfe-fep-pfa-tubing-fractional-sizes; vinyl: tygon-vinyl-tubing-e-3603-sizes; polyethylene: polyethylene-tubing-lldpe-sizes. No files: flexible tubing is not drawn as a fixed shape. family OD as listed OD, in OD, mm ID, in ID, mm wall, in wall, mm bend radius, in (as printed) Standard nylon (inch) 1/8 0.125 3.18 0.079 2.01 0.023 0.58 3/8 Standard nylon (inch) 1/8 0.125 3.18 0.093 2.36 0.016 0.41 1/2 Standard nylon (inch) 5/32 0.1562 3.97 0.106 2.69 0.025 0.64 1/2 Standard nylon (inch) 3/16 0.1875 4.76 0.138 3.51 0.025 0.64 5/8 Standard nylon (inch) 1/4 0.25 6.35 0.125 3.18 0.062 1.57 3/8 Standard nylon (inch) 1/4 0.25 6.35 0.170 4.32 0.040 1.02 3/4 Standard nylon (inch) 1/4 0.25 6.35 0.180 4.57 0.035 0.89 1 Standard nylon (inch) 5/16 0.3125 7.94 0.232 5.89 0.040 1.02 1-1/2 Standard nylon (inch) 3/8 0.375 9.53 0.275 6.99 0.050 1.27 1-1/2 Standard nylon (inch) 1/2 0.5 12.70 0.375 9.53 0.062 1.57 2-1/4 Standard nylon (inch) 5/8 0.625 15.88 0.500 12.70 0.062 1.57 3-1/4 High-pressure nylon 11 (inch) 1/8 0.125 3.18 0.073 1.85 0.026 0.66 — High-pressure nylon 11 (inch) 3/16 0.1875 4.76 0.109 2.77 0.039 0.99 — High-pressure nylon 11 (inch) 1/4 0.25 6.35 0.150 3.81 0.050 1.27 — High-pressure nylon 11 (inch) 3/8 0.375 9.53 0.225 5.72 0.075 1.91 — High-pressure nylon 11 (inch) 1/2 0.5 12.70 0.350 8.89 0.075 1.91 — D.O.T. nylon 11 (inch; no ID printed) 1/8 0.125 3.18 0.079 (derived) 2.01 0.023 0.58 — D.O.T. nylon 11 (inch; no ID printed) 5/32 0.1562 3.97 0.092 (derived) 2.34 0.032 0.81 — D.O.T. nylon 11 (inch; no ID printed) 3/16 0.1875 4.76 0.116 (derived) 2.93 0.036 0.91 — D.O.T. nylon 11 (inch; no ID printed) 1/4 0.25 6.35 0.170 (derived) 4.32 0.040 1.02 — D.O.T. nylon 11 (inch; no ID printed) 5/16 0.3125 7.94 0.232 (derived) 5.91 0.040 1.02 — Standard nylon (metric) 3 mm 0.1181 3 0.071 1.8 0.024 0.6 — Standard nylon (metric) 4 mm 0.1575 4 0.106 2.7 0.026 0.65 — Standard nylon (metric) 5 mm 0.1969 5 0.118 3 0.039 1 — Standard nylon (metric) 6 mm 0.2362 6 0.157 4 0.039 1 — Standard nylon (metric) 8 mm 0.315 8 0.236 6 0.039 1 — Standard nylon (metric) 10 mm 0.3937 10 0.315 8 0.039 1 — Standard nylon (metric) 12 mm 0.4724 12 0.394 10 0.039 1 — High-pressure nylon 11 (metric) 5 mm 0.1969 5 0.118 3 0.039 1 — High-pressure nylon 11 (metric) 6 mm 0.2362 6 0.157 4 0.039 1 — High-pressure nylon 11 (metric) 8 mm 0.315 8 0.236 6 0.039 1 — High-pressure nylon 11 (metric) 10 mm 0.3937 10 0.315 8 0.039 1 — High-pressure nylon 11 (metric) 12 mm 0.4724 12 0.394 10 0.039 1 — Files elsewhere (not hosted by Xem Studio; license as stated by the publisher): - Freelin-Wade: Nylon tubing: standard nylon (inch and metric), D.O.T. nylon 11, high-pressure nylon 11: OD, ID, wall, bend radius — web — Maker datasheet; numbers only — https://www.freelin-wade.com/documents/Nylon.pdf No true-size file yet: the published figures do not fix the whole shape; a measured scan is planned. API: https://xemstudio.com/api/geometry?object=nylon-tubing-inch-metric-sizes