🔄 Tube Size Unit Converter (mm ⇄ inch)
Note: 1 inch = 25.4 mm. US-spec tubes are often nominal in inches (e.g. 1″ OD) — confirm actual mm tolerances when ordering.
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Why Tube Buyers Need mm ⇄ Inch Conversion
Carbon fiber tubing lives in two measurement worlds: Chinese and European factories quote millimeters, while the US market still orders nominal inches (1″, 1.5″, 2″ OD). This free mm to inch converter translates instantly both ways, converts wall thickness too, and lists the six most common US tube sizes from 1/2″ (12.7 mm) to 2″ (50.8 mm) for one-click lookup.
Nominal vs Actual — Read Before Ordering
A “1-inch tube” is rarely exactly 25.40 mm — pultruded imperial tooling, sanding allowances, and tolerance bands (±0.05–0.15 mm typical) shift the real number. Always confirm the actual OD/ID in millimeters on the drawing before production. All WHABEST stock tubes are dimensioned in mm with stated tolerances; inch equivalents in listings are convenience conversions, and our custom shop builds to your print either way.
Quick Reference: Common Inch Sizes in mm
1/2″ = 12.7 mm · 3/4″ = 19.05 mm · 1″ = 25.4 mm · 1-1/4″ = 31.75 mm · 1-1/2″ = 38.1 mm · 2″ = 50.8 mm. For wall: 1/16″ ≈ 1.59 mm, 1/32″ ≈ 0.79 mm. Bookmark this page if you regularly cross-quote US and metric suppliers — and when you are ready, send your inch-spec BOM and we will convert, tolerance-check, and quote within 12 hours.
Frequently Asked Questions
Is 25.4 mm exactly 1 inch?
Yes, by international definition since 1959. All conversions on this page use 1 in = 25.4 mm exactly.
Do you manufacture to inch drawings?
Absolutely — send imperial prints and we produce to them, verifying critical fits in both units. Contact engineering.
What tolerance do stock metric tubes hold?
Roll-wrapped OD typically ±0.10 mm; pultruded ±0.05 mm. Tighter (ground OD) available on request.
Wall Thickness Conversions Engineers Bookmark
Tube walls in the composites world are thin: 1.0 mm (0.039 in), 1.5 mm (0.059 in), 2.0 mm (0.079 in), and 3.0 mm (0.118 in) cover 90% of structural orders. When converting a US print that calls out 0.06 in wall, you land at 1.52 mm — practically our 1.5 mm stock, which is why cross-referencing this converter with our sizes chart saves a full email round-trip. Length conversions matter too: standard 1 m stock equals 39.37 in, and 2 m sticks (78.74 in) fit most LTL freight without oversize fees.
Tolerance Stack-Up When Switching Units
Rounding kills fits. A 25.4 mm nominal tube at plus-or-minus 0.1 mm spans 25.30–25.50 mm, i.e. 0.996–1.004 in — fine for clamps, fatal for press-fit bearings. Rule: convert, then re-apply the tolerance band in the target unit, and confirm weight impact with our weight calculator before releasing the PO. Every WHABEST stock tube lists metric dimensions with explicit tolerances so your inch math always has a solid anchor, and engineering double-checks conversions free on every quote.