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Tubing Size Chart: OD, ID and Working Pressure by Model

By YUANNAI TUBEPublished Updated
Three tube sizes in order with a caliper measuring the largest

This tubing size chart lists every standard pneumatic tubing size and the tubing dimensions we manufacture, with model, outside diameter, inside diameter, wall thickness, working pressure and minimum bend radius for all eight material families. All figures come from our own published model tables — nothing here is generic industry data.

Quick answer. Standard metric pneumatic tubing sizes include 4 mm, 6 mm, 8 mm, 10 mm, 12 mm, and 16 mm outside diameter (OD), paired with matching fractional imperial sizes (1/8″, 1/4″, 3/8″, 1/2″, and 3/4″) under shared model codes (0425 through 1612), with fractional sizes from 1/8″ to 1/2″ (plus 3/4″ on two families). Tolerance is ±0.10 mm on both diameters across every family. Find your size in the family table below, then confirm the working pressure at your operating temperature — the ratings differ by material at the same size.

How to read the chart

Tubing is specified by outside diameter and inside diameter; the wall is the half-difference of the two, shown here rounded to two decimals. Fittings accept one specific OD-and-wall combination, so match the chart to the fitting seat rather than to a nominal name — the size and wall thickness guide explains the conventions and includes a worked example.

Working pressures are the published ratings for each model. They hold at the stated reference temperature; the working pressure and temperature review covers derating before you use them on a hot line.

PU Tubing sizes (15 models)

The standard polyurethane range: the tightest bend radii in the catalogue, rated 5–8 bar on metric sizes. Full details on the PU tubing page.

Model OD (mm) ID (mm) Wall (mm) Working pressure Min. bend radius
YN-PU 0425 4.0 2.5 0.75 8 bar (128 psi) 10 mm
YN-PU 0640 6.0 4.0 1 8 bar (128 psi) 15 mm
YN-PU 0850 8.0 5.0 1.5 7 bar (116 psi) 20 mm
YN-PU 0855 8.0 5.5 1.25 6 bar (99 psi) 22 mm
YN-PU 0860 8.0 6.0 1 5 bar (75 psi) 25 mm
YN-PU 1065 10.0 6.5 1.75 7 bar (106 psi) 25 mm
YN-PU 1080 10.0 8.0 1 6 bar (94 psi) 30 mm
YN-PU 1280 12.0 8.0 2 7 bar (104 psi) 50 mm
YN-PU 1410 14.0 10.0 2 7 bar (106 psi) 70 mm
YN-PU 1612 16.0 12.0 2 7 bar (109 psi) 95 mm
1/8 3.17 1.58 0.79 12 bar (174 psi) 8 mm
1/4 6.35 4.35 1 10 bar (145 psi) 16 mm
3/8 9.52 6.35 1.58 10 bar (145 psi) 25 mm
1/2 12.7 9.6 1.55 8 bar (116 psi) 35 mm
3/4 19.05 15.88 1.58 6 bar (87 psi) 65 mm

Polyether Tubing sizes (14 models)

The polyether-TPU grade: same sizes and codes as PU, higher metric pressure ratings, the default for humid service. Full details on the Polyether tubing page.

Model OD (mm) ID (mm) Wall (mm) Working pressure Min. bend radius
YN-PUR 0425 4.0 2.5 0.75 10 bar (145 psi) 15 mm
YN-PUR 0640 6.0 4.0 1 10 bar (145 psi) 25 mm
YN-PUR 0850 8.0 5.0 1.5 12 bar (175 psi) 30 mm
YN-PUR 0855 8.0 5.5 1.25 8 bar (116 psi) 40 mm
YN-PUR 0860 8.0 6.0 1 8 bar (116 psi) 40 mm
YN-PUR 1065 10.0 6.5 1.75 10 bar (145 psi) 40 mm
YN-PUR 1080 10.0 8.0 1 8 bar (116 psi) 45 mm
YN-PUR 1280 12.0 8.0 2 10 bar (145 psi) 50 mm
YN-PUR 1410 14.0 10.0 2 10 bar (145 psi) 70 mm
YN-PUR 1612 16.0 12.0 2 8 bar (116 psi) 95 mm
1/8″ 3.18 1.7 0.74 12 bar (174 psi) 8 mm
1/4″ 6.35 4.35 1 10 bar (145 psi) 16 mm
3/8″ 9.52 6.35 1.58 10 bar (145 psi) 25 mm
1/2″ 12.70 9.52 1.59 8 bar (116 psi) 35 mm

PA6 Nylon Tubing sizes (14 models)

General-purpose nylon: the highest pressure ratings in the range on most sizes, at the cost of larger bend radii. Full details on the PA6 Nylon tubing page.

Model OD (mm) ID (mm) Wall (mm) Working pressure Min. bend radius
YN-PA6 0425 4.0 2.5 0.75 41 bar (592 psi) 40 mm
YN-PA6 0640 6.0 4.0 1 35 bar (512 psi) 35 mm
YN-PA6 0850 8.0 5.0 1.5 28 bar (412 psi) 45 mm
YN-PA6 0855 8.0 5.5 1.25 28 bar (412 psi) 47 mm
YN-PA6 0860 8.0 6.0 1 23 bar (341 psi) 48 mm
YN-PA6 1065 10.0 6.5 1.75 31 bar (455 psi) 65 mm
YN-PA6 1080 10.0 8.0 1 18 bar (265 psi) 80 mm
YN-PA6 1280 12.0 8.0 2 22 bar (331 psi) 70 mm
YN-PA6 1410 14.0 10.0 2 25 bar (363 psi) 140 mm
YN-PA6 1612 16.0 12.0 2 22 bar (327 psi) 160 mm
1/8″ 3.175 1.58 0.8 20 bar (290 psi) 32 mm
1/4″ 6.35 4.35 1 14 bar (203 psi) 65 mm
3/8″ 9.525 6.35 1.59 14 bar (203 psi) 100 mm
1/2″ 12.70 9.60 1.55 10 bar (145 psi) 130 mm

PA12 Nylon Tubing sizes (14 models)

Low-moisture-absorption nylon for stable dimensions in wet service and high-pressure circuits. Full details on the PA12 Nylon tubing page.

Model OD (mm) ID (mm) Wall (mm) Working pressure Min. bend radius
YN-PA12 0425 4.0 2.5 0.75 29 bar (426 psi) 20 mm
YN-PA12 0640 6.0 4.0 1 27 bar (398 psi) 30 mm
YN-PA12 0850 8.0 5.0 1.5 29 bar (426 psi) 30 mm
YN-PA12 0855 8.0 5.5 1.25 19 bar (266 psi) 45 mm
YN-PA12 0860 8.0 6.0 1 17 bar (256 psi) 50 mm
YN-PA12 1065 10.0 6.5 1.75 24 bar (355 psi) 80 mm
YN-PA12 1080 10.0 8.0 1 14 bar (213 psi) 85 mm
YN-PA12 1280 12.0 8.0 2 16 bar (241 psi) 93 mm
YN-PA12 1410 14.0 10.0 2 12 bar (174 psi) 75 mm
YN-PA12 1612 16.0 12.0 2 14 bar (213 psi) 95 mm
1/8″ 3.175 1.58 0.8 20 bar (290 psi) 25 mm
1/4″ 6.350 4.35 1 14 bar (203 psi) 30 mm
3/8″ 9.525 6.35 1.59 14 bar (203 psi) 80 mm
1/2″ 12.70 9.60 1.55 10 bar (145 psi) 125 mm

PE Tubing sizes (14 models)

The economical polyethylene range for low-to-medium pressure air and water lines. Full details on the PE tubing page.

Model OD (mm) ID (mm) Wall (mm) Working pressure Min. bend radius
YN-PE 0425 4.0 2.5 0.75 6 bar (87 psi) 20 mm
YN-PE 0640 6.0 4.0 1 6 bar (87 psi) 30 mm
YN-PE 0850 8.0 5.0 1.5 7 bar (113 psi) 40 mm
YN-PE 0855 8.0 5.5 1.25 5 bar (73 psi) 45 mm
YN-PE 0860 8.0 6.0 1 6 bar (99 psi) 50 mm
YN-PE 1065 10.0 6.5 1.75 6 bar (87 psi) 50 mm
YN-PE 1080 10.0 8.0 1 4 bar (71 psi) 75 mm
YN-PE 1280 12.0 8.0 2 5 bar (85 psi) 60 mm
YN-PE 1410 14.0 10.0 2 5 bar (73 psi) 80 mm
YN-PE 1612 16.0 12.0 2 3 bar (56 psi) 110 mm
1/8″ 3.175 1.58 0.8 8 bar (116 psi) 16 mm
1/4″ 6.35 4.35 1 5 bar (73 psi) 35 mm
3/8″ 9.525 6.35 1.59 6 bar (87 psi) 50 mm
1/2″ 12.70 9.60 1.55 4 bar (58 psi) 80 mm

FEP Tubing sizes (14 models)

Fluoropolymer for chemical service and purity, transparent, rated 10–20 bar on metric sizes. Full details on the FEP tubing page.

Model OD (mm) ID (mm) Wall (mm) Working pressure Min. bend radius
YN-FEP 0425 4.0 2.5 0.75 16 bar (224 psi) 25 mm
YN-FEP 0640 6.0 4.0 1 17 bar (238 psi) 40 mm
YN-FEP 0850 8.0 5.0 1.5 20 bar (280 psi) 60 mm
YN-FEP 0855 8.0 5.5 1.25 20 bar (280 psi) 65 mm
YN-FEP 0860 8.0 6.0 1 13 bar (182 psi) 70 mm
YN-FEP 1065 10.0 6.5 1.75 19 bar (270 psi) 80 mm
YN-FEP 1080 10.0 8.0 1 14 bar (196 psi) 110 mm
YN-FEP 1280 12.0 8.0 2 18 bar (261 psi) 100 mm
YN-FEP 1410 14.0 10.0 2 12 bar (168 psi) 120 mm
YN-FEP 1612 16.0 12.0 2 10 bar (145 psi) 160 mm
1/8″ 3.175 1.58 0.8 16 bar (232 psi) 13 mm
1/4″ 6.350 4.35 1 10 bar (145 psi) 50 mm
3/8″ 9.525 6.35 1.59 10 bar (145 psi) 26 mm
1/2″ 12.70 9.60 1.55 6 bar (87 psi) 130 mm

PFA Tubing sizes (14 models)

The premium fluoropolymer grade for higher temperature and high-purity lines. Full details on the PFA tubing page.

Model OD (mm) ID (mm) Wall (mm) Working pressure Min. bend radius
YN-PFA 0425 4.0 2.5 0.75 16 bar (224 psi) 30 mm
YN-PFA 0640 6.0 4.0 1 17 bar (238 psi) 36 mm
YN-PFA 0850 8.0 5.0 1.5 20 bar (280 psi) 50 mm
YN-PFA 0855 8.0 5.5 1.25 20 bar (280 psi) 55 mm
YN-PFA 0860 8.0 6.0 1 13 bar (182 psi) 64 mm
YN-PFA 1065 10.0 6.5 1.75 19 bar (270 psi) 80 mm
YN-PFA 1080 10.0 8.0 1 14 bar (196 psi) 88 mm
YN-PFA 1280 12.0 8.0 2 18 bar (261 psi) 72 mm
YN-PFA 1410 14.0 10.0 2 12 bar (168 psi) 98 mm
YN-PFA 1612 16.0 12.0 2 10 bar (87 psi) 128 mm
1/8″ 3.175 1.58 0.8 16 bar (232 psi) 14 mm
1/4″ 6.350 4.35 1 10 bar (145 psi) 37 mm
3/8″ 9.525 6.35 1.59 10 bar (145 psi) 40 mm
1/2″ 12.70 9.60 1.55 6 bar (87 psi) 100 mm

High-Pressure Composite Tubing sizes (28 models)

Two-layer reinforced construction in two variants, rated 12–19 bar with hose-like flexibility at small sizes. Full details on the high-pressure composite tubing page.

V8 structure: PU outer layer + PA12 inner layer

Model OD (mm) ID (mm) Wall (mm) Working pressure Min. bend radius
YN-0425 4.0 2.5 0.75 16 bar(242 psi) 10 mm
YN-0640 6.0 4.0 1 14 bar(213 psi) 15 mm
YN-0850 8.0 5.0 1.5 15 bar(228 psi) 20 mm
YN-0855 8.0 5.5 1.25 12 bar(185 psi) 20 mm
YN-0860 8.0 6.0 1 12 bar(185 psi) 20 mm
YN-1065 10.0 6.5 1.75 19 bar(284 psi) 25 mm
YN-1080 10.0 8.0 1 12 bar(185 psi) 31 mm
YN-1280 12.0 8.0 2 17 bar(256 psi) 35 mm
YN-1612 16.0 12.0 2 15 bar(228 psi) 71 mm
1/8 3.17 1.58 0.79 14 bar(196 psi) 7 mm
1/4 6.35 4.35 1 12 bar(168 psi) 22 mm
3/8 9.52 6.35 1.58 15 bar(228 psi) 24 mm
1/2 12.7 9.6 1.55 14 bar(196 psi) 32 mm
3/4 19.05 15.88 1.58 13 bar(213 psi) 70 mm

V9 structure: polyether TPU outer layer + PA12 inner layer

Model OD (mm) ID (mm) Wall (mm) Working pressure Min. bend radius
YN-0425 4.0 2.5 0.75 16 bar(232 psi) 16 mm
YN-0640 6.0 4.0 1 14 bar(203 psi) 16 mm
YN-0850 8.0 5.0 1.5 15 bar(218 psi) 29 mm
YN-0855 8.0 5.5 1.25 12 bar(174 psi) 29 mm
YN-0860 8.0 6.0 1 12 bar(174 psi) 29 mm
YN-1065 10.0 6.5 1.75 19 bar(276 psi) 44 mm
YN-1080 10.0 8.0 1 12 bar(174 psi) 30 mm
YN-1280 12.0 8.0 2 17 bar(247 psi) 46 mm
YN-1612 16.0 12.0 2 15 bar(218 psi) 70 mm
1/8 3.17 1.58 0.79 15 bar(218 psi) 8 mm
1/4 6.35 4.35 1 14 bar(203psi) 15 mm
3/8 9.52 6.35 1.58 17 bar(247psi) 25 mm
1/2 12.7 9.6 1.55 15 bar(218psi) 35 mm
3/4 19.05 15.88 1.58 15 bar(218psi) 75 mm

Nylon tubing in inch sizes: 1/8, 1/4, 3/8 and 1/2

Searching by fractional size? Our nylon tubing is listed in inch sizes as well as metric. The inch rows follow the nominal outside diameter (1/8″ is 3.175 mm OD, 1/4″ is 6.35 mm, 3/8″ is 9.525 mm and 1/2″ is 12.70 mm) with a tolerance of ±0.10 mm, and working pressure is quoted at 23°C. PA6 and PA12 are different materials, so read each column for its own material and compare the two only at the same size. See the PA6 nylon tubing page and the PA12 nylon tubing page for the full model tables, data sheets and ordering details.

Nominal size OD (mm) ID (mm) PA6 working pressure PA12 working pressure
1/8″ 3.175 1.58 20 bar (290 psi) 20 bar (290 psi)
1/4″ 6.35 4.35 14 bar (203 psi) 14 bar (203 psi)
3/8″ 9.525 6.35 14 bar (203 psi) 14 bar (203 psi)
1/2″ 12.7 9.6 10 bar (145 psi) 10 bar (145 psi)

Reading the patterns

Three patterns repeat across the chart and are worth knowing before you pick a row. First, pressure falls as diameter grows within a family, because pressure stress scales with diameter relative to wall. Second, at the same size the ratings differ sharply by material — a 8 × 5 tube runs from 7 bar in PU to 29 bar in PA6. Third, the smallest sizes carry the highest ratings everywhere: the 1/8″ tubes reach 8–20 bar depending on family.

Same outside diameter, different bore: what changes

Two tubes can share an outside diameter and still deliver different circuits. The table below uses two hypothetical 8 mm tubes to show how the inside diameter drives the internal cross-section and the air volume the line holds.

Dimension or calculation Tube A Tube B
Outside diameter 8 mm 8 mm
Inside diameter 5 mm 6 mm
Wall thickness 1.5 mm 1.0 mm
Internal cross-sectional area 19.6 mm² 28.3 mm²
Internal volume per meter 19.6 mL 28.3 mL

Source: geometric calculation, internal area = π × ID² ÷ 4 and volume = area × length. The dimensions are illustrative and are not model ratings or measured flow results.

Tube B has about 44% more internal cross-sectional area, but that does not mean 44% more airflow or a proportional gain in cylinder speed. Valves, fittings, supply pressure, exhaust path and tube length all affect response, and a thinner wall needs its own working-pressure check against the rows above.

Length matters as much as bore. Three meters of 6 mm ID tubing hold about 84.8 mL, against 28.3 mL for one meter. On a line that fills and exhausts every cycle, avoidable length adds volume, so shorten the route before assuming a larger diameter is the fix. When you order a replacement, write the size as OD × ID with units, because “8 mm tube” leaves the bore open.

If your size is not in the chart

The chart lists standard production models. Custom inside and outside diameters, wall thicknesses and coil lengths are confirmed case by case: send the dimensions, quantity, medium, temperature range and working pressure through the quotation checklist and we will confirm the feasible model and lead time. The full ranges sit on the product overview, and the material-level trade-offs are on the industrial tubing materials page.

Diameter readings displayed alongside a tubing production line
Fig. 1: Real-time outer diameter and wall thickness verification across standard extruded tubing batches.

Tubing size chart FAQ

What sizes does industrial tubing come in?

Our standard range covers metric sizes from 4 mm to 16 mm outside diameter (model codes 0425 through 1612) and fractional sizes from 1/8″ to 1/2″, with 3/4″ additionally available in PU and high-pressure composite. Tolerance is ±0.10 mm on both diameters in every family.

Is tubing sized by OD or ID?

By both, plus the wall between them. A fitting accepts one specific OD-and-wall combination, so two tubes with the same OD but different walls are not interchangeable. The size and wall thickness guide shows how to measure each figure.

Why do pressure ratings differ at the same size?

Material strength and construction differ: the same 8 × 5 size is rated from 7 bar (PU) to 29 bar (PA6) in the chart above. Use the material whose rating covers your working pressure at the actual operating temperature, with margin for cycling.

Are the model codes the same across materials?

Yes for the metric sizes: the four-digit code encodes the dimensions, so 0860 is 8 × 6 mm in every family, prefixed by material (YN-PU, YN-PUR, YN-PA6, YN-PA12, YN-PE, YN-FEP, YN-PFA). Only the rating and bend radius change with the material.

Can I order a size that is not listed?

Custom diameters, walls and coil lengths are confirmed case by case against quantity and application. Send the full requirement through the quotation checklist rather than assuming from the chart.

Next step. Pick the family that covers your pressure and medium, open its product page for burst pressures and datasheets, or send the five items from the quotation checklist for a confirmed offer.

Frequently Asked Questions: Tubing Sizes & Dimensions

What are the most common pneumatic tubing sizes in industrial automation?

The three most widely used pneumatic sizes globally are: 6 × 4 mm (the standard for solenoid valve pilot lines and compact cylinders), 8 × 5 mm or 8 × 5.5 mm (for medium cylinders and air distribution manifolds), and 1/4″ OD (6.35 mm) in North American machinery. For main air headers and heavy pneumatic tools, 10 mm and 12 mm OD lines are standard.

Why must tubing outside diameter (OD) have a tight tolerance for push-in fittings?

Push-to-connect (push-in) fittings rely on an internal stainless steel collet that bites into the tube OD, paired with an internal elastomeric O-ring that seals against the outer surface. If the tube OD is undersized by more than 0.10 mm, the O-ring cannot maintain adequate sealing pressure, causing micro-leaks. If oversized, insertion force becomes excessive and the collet can damage the wall. YUANNAI TUBE maintains strict ±0.05 mm to ±0.10 mm OD laser tolerances across all families.

How does tube inside diameter (ID) affect air tool performance?

Inside diameter determines cross-sectional flow area (proportional to ID squared) and dynamic pressure drop. Doubling the inside diameter from 4 mm to 8 mm increases volumetric air flow capacity by four-fold at the same supply pressure. For high-flow air motors or fast-cycling cylinders, choosing a thinner wall with a larger ID prevents sluggish cylinder speeds.

To match a size to a fitting, see push-in fittings and tubing.

To see how much air a given size carries over your line length, use the compressed air flow calculator.

Sources and scope

Use these documents for the identified product models and stated test conditions. General material comparisons and selection checklists do not establish a different grade’s rating, fitting compatibility or project approval. Confirm the exact model, medium, temperature, pressure and required evidence before ordering.

Content review: zhangkexin · Marketing

Review scope: market information and document references.

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