What this tool answers
You need a first-pass tube-bender size before buying. Enter the measured tube outside diameter in inches. The calculator names the smallest class on this site’s ladder — 50, 100, or 200 — that clears the published max OD, or returns NO_MATCH. It is not a structural engineering check, die chart substitute, or replacement for manufacturer instructions.
Why measured OD matters
Retail bender listings publish die sizes against outside diameter. Nominal pipe size and inside diameter are different numbers. Matching measured OD to published maxOd avoids undersizing against a die that will not seat and oversizing without a transparent class ladder.
Class ladder on this site
Classes use published VEVOR US pipe/tube-bender ratings checked 2026-09-10: (1) class 50 — handheld 3-in-1 for 1/4, 3/8, 1/2 in OD (maxOd 0.5), (2) class 100 — manual SWG-25 with 7 dies about 3/8–1 in OD (maxOd 1.0), (3) class 200 — 12-ton hydraulic with dies about 1/2–2 in (maxOd 2.0). Matching rule: smallest class where class.maxOd ≥ od_in.
When the answer is NO_MATCH
If measured OD exceeds 2 in, this site returns NO_MATCH for its published ladder. Typical next steps: confirm units (inches vs mm), re-measure OD vs ID, check for industrial benders outside this screen, or follow shop equipment guidance. Do not force an undersized die set.
Dies, wall thickness, and live systems
Match the die to measured outside diameter, not nominal pipe ID. Respect wall-thickness limits published for each die and material. On hydraulic units, bend gradually — do not force a kink. Wear PPE. Secure the workpiece. Never bend pressurized or live systems.
Sources
VEVOR US pipe/tube-bender product pages for die ranges and OD claims dated in products.json (checked 2026-09-10). Consumer sizing practice pairing measured OD with published maxOd. Safety framing follows common manufacturer warnings: die-to-OD match, wall-thickness limits, gradual hydraulic bends, PPE, secure workpiece, and no pressurized/live systems.