Material type, wall thickness, D‑ratio (tube OD ÷ wall thickness), bend radius, tooling condition, lubrication, and mandrel selection. Engineers typically aim for a D‑ratio below 15 for standard rotary‑draw bending, with tighter radii requiring mandrel support and wiper dies.

Minimum bend radius is influenced by material yield strength and wall factor. As a rule of thumb:

• Mild steel: radius ≈ 2–3 × tube OD

• Stainless: radius ≈ 3–4 × tube OD

• Aluminium: radius ≈ 1.5–2 × tube OD For precision work, engineers use empirical testing or manufacturer bend‑data tables.

Rotary‑draw bending uses a bend die, clamp die, pressure die, mandrel, and wiper to produce accurate, repeatable bends with controlled geometry. Compression bending pushes the tube around a form and is faster but less precise, typically used for simple bends or thicker‑wall material.

Mandrels are required when bending thin‑wall tube, tight radii, or when ovality must be controlled. Ball mandrels are used for multi‑radius or complex bends where flexibility is needed. Engineers specify mandrels when D‑ratio or bend radius exceeds standard limits.

Tooling wear causes slipping, increased ovality, wrinkling, and inconsistent bend angles. Engineers monitor clamp‑die grip, wiper‑die edge condition, and mandrel wear. Regular inspection and replacement maintain tolerance and repeatability.

Modern CNC machines (Addison, Langbow, Pedrazzoli, UNI series, TM/DB models) typically achieve:

• Bend angle accuracy: ±0.1°

• Rotation accuracy: ±0.1°

• Feed accuracy: ±0.1 mm Actual tolerance depends on tooling, lubrication, material consistency, and machine condition.

Yes. Replacement control systems (PLC/CNC) can be fitted to Addison, Langbow, Pedrazzoli, UNI, DB, TM and similar machines. Upgrades improve repeatability, diagnostics, safety, and integration with modern production workflows.

Springback varies by material and bend radius. Engineers compensate by:

• Overbending the programmed angle

• Using harder tooling materials

• Increasing clamp pressure

• Improving lubrication

• Using mandrel support CNC machines allow precise springback compensation per material batch.

Common causes include insufficient wiper‑die support, incorrect mandrel position, low clamp pressure, worn tooling, or bending below the material’s minimum radius. Engineers adjust tooling alignment and lubrication to eliminate wrinkles.

Collapse occurs when the tube wall cannot support the bend. Engineers correct this by:

• Using a mandrel

• Increasing wall thickness

• Increasing bend radius

• Improving pressure‑die support

• Adjusting tooling alignment Ovality is measured and controlled when tubes must meet strict dimensional requirements.

Engineers consider:

• Tube OD and wall thickness

• Material type

• Required bend radius

• Number of bends per part

• Rotation and feed complexity

• Production volume CNC machines suit complex, multi‑plane parts; compression or semi‑automatic machines suit simpler, high‑speed work.

Yes. We supply bend dies, clamp dies, pressure dies, wipers, mandrels, ball mandrels, and custom tooling for Addison, Langbow, Pedrazzoli, UNI, DB, TM and most other machines. Tooling is engineered for precision, durability, and repeatability.