Shaping Steel with Accuracy: Draw Bench Cold Processing

Draw Bench

Cold drawing is a precision cold-working method used after extrusion to refine seamless pipes. This process involves pulling the pipe through a die using tensile force at room temperature, without heat, to reduce diameter and enhance dimensional accuracy, surface finish, and mechanical strength.

At Stancor Tubulars, cold drawing is performed on advanced mechanical draw benches. The process begins with carefully selected raw materials, followed by pointing (end tapering) using methods like push pointing or swaging. Two main techniques are used:

Rod Drawing: A mandrel is inserted inside the tube to control both outer diameter and wall thickness.
Sink Drawing: No internal support; reduces only outer diameter and is often used as a sizing pass.

Proper lubrication (e.g., chlorinated oils) ensures smooth drawing and prevents wear. The final cold drawn pipes exhibit a polished finish, improved grain structure, tight tolerances, and enhanced machinability. Optional annealing relieves internal stresses before packing and delivery.

-> Cold drawing reduces outer diameter and increases pipe length using mechanical force via a draw bench.

-> Two drawing methods: Rod Drawing (with mandrel) for controlled wall thickness; Sink Drawing (without mandrel) for outer diameter sizing.

-> Pointing techniques like push pointing and rotary swaging prepare tubes for drawing by reducing end diameter.

-> Cold working at ambient temperature enhances grain uniformity and metal strength.

-> Lubrication (typically chlorinated oil) minimizes friction, ensures smooth drawing, and extends tool life.

-> Resulting pipes exhibit a clean, polished surface finish and high dimensional accuracy.

-> Optional annealing relieves internal stress and improves machinability.

-> Final products meet strict tolerance requirements with improved mechanical properties and surface quality.

-> Drawn pipes are inspected, packed, and shipped for global industrial applications.