Short answer: An arch roof (K-span type) roll forming machine forms coil into a self-supporting panel profile, curves each panel to the arch radius and cuts it to length; the panels are then seamed together on site, so the arch needs no beams or trusses. We build the line in our Xiamen factory to your profile and span, trial it with your coil and quote within 24 hours.
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We manufacture every Halcyon machine in our factory in Xiamen, China — more than 35 years of roll forming manufacturing experience.
What is an arch roof (K-span type) roll forming machine?
An arch roof building is made from coil that is first roll formed into a straight panel, then curved to the arch radius and finally seamed to the next panel. Because the arch works as the structure, it covers warehouses, machinery and grain storage, workshops and sports courts without intermediate trusses. The arch roof roll forming machine does the forming, curving and cutting in one line; the seamer joins the panels on site. Buyers also call it a K-span machine, arch building machine or self-supporting roof machine.
Arch roof building or steel-frame building?
| Question | Arch roof (K-span type) | Steel-frame building |
|---|---|---|
| Structure | The curved, seamed panels are the structure | Steel frame (columns, rafters, purlins) carries the roof sheets |
| Machines needed | Panel roll former + curving unit + cutting + seamer | Roof sheet roll former; frame from purlin and structural lines |
| Where it is formed | Often on site from a trailer-mounted line | Usually in a fixed plant |
| Typical uses | Warehouses, grain and machinery storage, workshops, sports courts, hangars | Any building size and layout |
| What sets the span | The project engineer's design for profile, gauge, radius and loads | The steel frame design |
For a framed building see our C/Z purlin roll forming machine and trapezoidal roof sheet machine.
Machines in the line
| Unit | Job | Confirm in the quotation |
|---|---|---|
| Decoiler | Feeds the galvanized or pre-painted coil | Coil width and weight |
| Roll former | Forms the arch panel profile straight | Profile drawing, gauge range, number of stations, roll material |
| Curving (crimping) unit | Curves each panel to the arch radius | Radius range for your profile and gauge, adjustment method |
| Cut-off and PLC control | Cuts each panel to the arch length | Length accuracy, PLC brand, voltage |
| Seaming machine | Joins the panels on site | Seam type matching your profile |
| Trailer (optional) | Produces directly at the job site | Dimensions, generator or grid power, local road rules |
How we quote and test
- You send the profile, gauge, span and rise (or radius) and panel lengths.
- Our engineering team in Xiamen proposes the configuration and scope in writing.
- Before shipment we run the line with your profile and coil; you receive the trial video and sample measurements.
- FOB China shipment with manual, electrical drawings and installation support.
The span, gauge and radius an arch building can reach depend on your project engineer's design; the machine trial checks the formed and curved panel, not the structural capacity of the building.
Related: roof panel curving machine (curving straight sheets), portable roll forming machine (on-site standing seam and gutters). En español: roladora para arcotecho.
Arch roof roll forming machine FAQ
What is a K-span type arch building?
It is a metal arch building made from roll-formed panels that are curved and seamed together. The arch itself carries the loads, so it is often called a self-supporting or no-frame building and is used for warehouses, storage halls, workshops and courts. Span, gauge and radius are set by the project engineer.
What does an arch roof roll forming line include?
Usually a decoiler, the panel roll former, a curving (crimping) unit, cut-to-length with PLC control and a seaming machine to join panels on site. The line can be mounted on a trailer for on-site production. The exact scope is confirmed in writing in the quotation.
How much does an arch roof roll forming machine cost?
It depends on the profile, gauge range, curving system, trailer mounting and whether the seamer is included. We do not publish a price range for this line yet: send your profile, span and gauge and we reply with a configuration and price within 24 hours.
Do you have photos or video of the machine?
The images on this page are reference images (a panel curving unit and a roof panel line). Every arch roof line is configured to your profile; before balance payment you receive photos and the trial video run with your profile and coil.
What should I send for a quotation?
Profile drawing or photo, cover width and depth, gauge and material (galvanized or pre-painted), span and rise or radius of the arch, panel lengths, whether you need on-site production (trailer) and the available voltage.
K-SPAN is a trademark of its owner. Halcyon is not affiliated with it; the term is used here only to describe the arch building type.
Send your arch panel profile – quotation within 24 hours.
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