C+ / Sigma / Omega Profile Line

Yes, with a cassette-change configuration C, sigma and omega run on the same frame. The more sections you run, the faster a quick-change arrangement pays for itself.

With an adjustable cassette structure the height is selected on the panel; if the section family changes, the roller set is swapped.

Rollers are made from 4140 steel and hardened to 58-60 Rockwell; with correct pressure settings they can produce millions of metres of profile.

The adjustment covers a range of widths and heights within one section family and the geometry it was designed around. What it does not do is turn one profile family into another: moving between C, Sigma and Omega is a roller set matter, and moving outside the designed range means new tooling regardless of how much adjustment the machine has. The honest way to specify a line like this is to give the full list of sections you expect to produce, including the ones you do not have orders for yet, and let the range be designed around that list.

Because a bow can often be pulled out during erection and a twist cannot. C and Sigma sections are asymmetric about at least one axis, so residual stress left in the strip does not release as a simple curve — it releases as a rotation along the length. A twisted purlin will not sit flat where it bolts, and the fix on site is usually to reject the piece. This is why the straightening stage carries more weight on a structural line than most buyers expect, and why it is worth asking about specifically.

Hole position and spacing are recipe values, so a new layout is a data change rather than a tooling change. Hole shape and size are tooling — a different diameter or a slot instead of a round hole means a punch and die. When you plan the line, it is worth listing every hole shape you use across your product range at the start, because adding shapes later is a purchase each time while adding positions is free.

Longer than most people expect, and it depends much more on what runs through them than on hours. Uncoated steel, abrasive coatings, thick material and tight radii all wear tooling faster than light galvanized sheet at generous radii. Rolls are a maintenance item rather than a consumable — they are re-machined rather than replaced when they eventually go out of tolerance. What actually kills a roll set early is running it misaligned or under too much pressure, which is a setup discipline question more than a metallurgy one.

It depends on the mix, and it is worth doing the arithmetic rather than assuming. An adjustable line wins when the order book is varied and no single section dominates — you buy one machine, one control system and one set of spares, and changeovers are frequent but short. Two dedicated lines win when two sections make up most of the volume, because each runs at its own optimum with no changeover at all. If one section is more than roughly half your output, dedicating a line to it usually pays.