Resarch: Flatness problems by End-users

To gain a deeper understanding of how flatness problems affect the end-users, Shapeline has conducted a project to build up internal knowledge.

Flat steel is used for various purposes in the industry. Steel is welded, stamped, bent, cut, shaped, machined etc. into all kinds of final structures. In most of these processes, bad flatness is an issue which increases costs and delivery times. To build up internal knowledge, Shapeline has contacted 50 different manufacturing companies using flat steel in their processes. Most of them were also visited by a Shapeline representative.

The result was that most end-users have problems in varying degree. About 45% are actually willing to pay more for better flatness (see the diagram below) and the cost for flatness problems was estimated at 40-100 Euro/ton, depending on the application.

A majority of the companies realise that they are too small to influence the steel producers and instead, actively select material from suppliers, which fulfil their flatness requirements.

Some other conclusions were:

  • The cost for arc welding increases dramatically when the flatness gets worse. Amplitudes as small as 1,5 mm cause severe problems when thick steel plates are to be welded together.
  • In laser-cutting, faster lasers require flatter material. Flatness problems are one of the main cost factors.
  • On a direct question as to whether flat steel users are prepared to pay more for flat material, 45% said yes. The accepted price increase is 4-17% with an average of 10%. However, most users expect the suppliers to supply flat steel.
  • Reclamations are limited since
  • Flatness tolerances are wide. Many manufacturers need better flatness than the tolerances permit.
  • The users cannot wait for new material.
  • There are intermediate actors (steel service centres and traders), which filter feedback to the steel producers.
  •  Many producers select suppliers depending on the material flatness.

The need for good flatness seems to increase rather than decrease in the future since automation as well as focus on cost reductions increase. It is also likely that the rules for flatness evaluation will change to reflect the end-user requirements to a higher extent. Some steel producers are already using alternative flatness evaluation rules today and ½ or ¼ of standard tolerances are also commonly used. New evaluations will be hard or impossible to implement without a good, automated and high-density flatness gauge.