Why Profile Wire Is Ordered by Section, Not by Gauge | ERQI WIRE

Almost every other kind of wire is bought with one number: 3 mm, 12 gauge, 0.8 mm. That works because round wire has one dimension that decides everything. Profile wire does not, and the habit of ordering it by gauge sits behind a large share of the wrong deliveries we see.

What a gauge number cannot describe

A gauge tells you thickness at one point. A profile section has a face width, a height, an included angle, at least one corner radius and often a defined flat. Two sections can both be sold as “2 mm wire” and behave nothing alike in the same screen: one gives a 0.30 mm slot, the other 0.45, and the open area differs by a third. The number on the box is the same; the screen is not.

What belongs on the order instead

• A section drawing, to scale, with every dimension that touches a mating part called out.
• Material grade, and the environment if it is not obvious — chlorides decide between 304 and 316L more often than price does.
• Temper or finish: bright-drawn if the part has to hold shape, annealed if it has to be formed or welded.
• Tolerance per dimension, not one blanket number for the whole drawing.
• Supply form: coil weight range, spool type, or cut length.

Mark the dimensions you do not care about

This is the one that saves the most money and gets skipped the most. A dimension left blank on a drawing is read as functional, so it gets a functional tolerance and a functional price. Write “reference” next to anything that only matters visually, and the quote comes down without the part getting worse.

The one number worth using as a name

Across-flats, because everyone in the chain recognises it and it can be checked with a micrometer on the shop floor. Use it as the short name — “1.8 × 2.7 triangular” — and never as the whole specification.

If you only have a sample and no drawing, send the sample: we measure the section and send a drawing back for approval before anything is drawn. That route is described in from drawing to sample. The full range is on the profile wire page, and contact takes the drawing directly.