Drawing processes — mandrel usage: In which metalworking operation is a moving (floating) mandrel commonly used to support the work and control internal diameter?

Introduction / Context:
Mandrels are internal supports used to control inside diameter, wall thickness, and ovality during forming. Recognising where a moving or floating mandrel is applied is central to understanding tube manufacturing sequences and achievable tolerances.

Given Data / Assumptions:

• Tubes are reduced in diameter and/or thickness by drawing through a die.
• Internal support may be fixed, moving (floating), or plug-type.
• Goal is consistent inner geometry and surface finish.

Concept / Approach:
In tube drawing, a floating (moving) mandrel is entrained by lubricant and metal flow, positioning itself at the die throat. It shapes the internal surface while the die forms the external surface, controlling wall thickness and roundness. In wiredrawing, there is no internal cavity; in forging or machining, mandrels may be used, but the specific “moving mandrel” refers to tube drawing practice.

Step-by-Step Solution:
Identify need for internal support: hollow product → tube drawing.Select floating mandrel to minimise tooling length and ease threading.Die + mandrel combination sets outer and inner diameters.Therefore, moving mandrel usage corresponds to tube drawing.

Verification / Alternative check:
Process schematics of tube drawing show mandrel types: fixed, floating, and plug; wiredrawing lacks an internal tool.

Why Other Options Are Wrong:
Wiredrawing is solid; no mandrel needed.

Metal cutting and forging may use arbors or cores in special cases, but not the floating mandrel of tube drawing.

Press braking is sheet bending; mandrels are irrelevant.

Common Pitfalls:
Poor lubrication causing mandrel scoring; incorrect mandrel position leading to wall non-uniformity; excessive reduction per pass causing tube tearing.

Final Answer:
tube drawing