Understanding Tolerances When Cutting to Size

Tolerance in steel references a range of measurements permitted for manufacturers, given that metal forming involves certain unpreventable variations. Understanding the tolerances of the steel you’re working with is vital if you want to prevent an embarrassing disaster in your planned construction or use of cut metal.

Let’s dig into the three basic types of tolerance and their respective design parameters. Mill tolerances cover camber and sweep and the other two; Fabrication and Erections tolerances effectively go together, so we’ll group them like that for you here below.

Mill Tolerances

Manufacturers of steel know well what is expected of them concerning specifications for acceptable variances: cross-section, length, straightness, sweep, and camber properties. Within the categories under mill tolerances, are further descriptions referencing hot-rolled or cold-rolled structural steel. Camber tolerances are broken up into two further groups;

  • Incidental Mill Camber
  • Induced Mill Camber

Bear in mind that incidental or not, if you are needing steel for a beam or a column, you’ll not want any camber whatsoever. For that, you can set a ‘no camber’ specification. Straightness, sweep, and camber per length need to be noted for Mill tolerances.

For cutting, there are the two most likely metal applications you would be working with and a list underneath of what they are commonly used for:

Cold-Rolled Metal Applications

  • Automotive Engine Parts
  • Aerospace components
  • Medical devices

Hot-Rolled Metal Applications

  • Railroad tracks
  • Metal Structures
  • Furniture and Ornaments

Fabrication and Erection Tolerances

Putting these two together for the specs happens because they most often reference steel to be used for beam and pillar application. For both of these categories the following need consideration;

  • Location of work points
  • Temperature expansion and shrinkage
  • Column clearance
  • Beam and Column straightness
  • Beam and Column alignment
  • Erection tolerance at column splices
  • Fabrication tolerances for beam and column length

Architectural Tolerances

Mill and pipe tolerances have specs to meet and AESS (Architecturally Exposed Structural Steel) has an additional set of tolerances. Fabrication and Erections are subject to quality control specs over and above the tolerance margins.

The value of understanding variation in steel tolerances goes deeper than just the architect’s office. Communication between the fabricator, the erector, and the contractor from the design and construction process onward must be effective and clear.

Working with such fine-tuned specifications and tolerances is what makes steel manufacturers experts in their field. State-of-the-art technology and precision is the name of the game for Speak to our friendly team about your requirements at your convenience.