Purlin roll forming machine series

Purlin Roll Forming Machine for C, Z, U and Sigma Sections

A purlin roll forming machine turns galvanized coil into the secondary framing of a steel building. Web depth runs 75 to 350 mm, flange 35 to 80 mm, material 1.5 to 5.0 mm, with punching, notching and cutoff inside the same pass.

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Five designs, from manual spacer adjustment to a switchable C and Z mill. Built in Wuxi since 2005.

Purlin roll forming machine line with control cabinet in the workshop

One mill, two sectionsSwitchable C and Z tooling, motorized web and flange adjustment, and one punch die set per hole pattern.

75-350Web depth, mm

1.5-5.0Material thickness, mm

14-24Forming stations

10-30Line speed, m/min

C and ZSwitchable on one mill

Profiles

Four sections build a steel building

Purlins carry roof and wall load back to the frame. The section you choose sets the web depth, the flange width and the punch pattern the machine has to run. A purlin roll forming machine is built around that section, not the other way round.

01 / C

C purlin

Flat back and square flanges. The default roof purlin and wall girt on portal frame buildings, and the simplest section to form.

02 / Z

Z purlin

Offset flanges let two Zs nest and overlap over a rafter, so the run behaves continuous and spans further on the same steel.

03 / U

U and eave

Channel sections at the eave, the base rail and the door head. Usually a second tooling set on the same mill.

04 / Sigma

Sigma purlin

An extra pair of bends in the web lifts the strength to weight ratio, so a shallower section carries the same load.

Machine range

Five purlin machine designs

Every purlin roll forming machine here shares the same frame and control platform. What separates them is changeover speed, thickness capacity and how many strands run at once.

01 / C and Z

C Z Purlin Roll Forming Machine

Both sections on one mill with switchable tooling and motorized web and flange setting. The usual choice for a plant selling to more than one builder.

C and Z1.5 to 5.0 mmMotorized adjust

View C Z purlin machine →

02 / C only

C Purlin Roll Forming Machine

Dedicated C line from manual spacer adjustment to a reinforced version that forms 5.5 mm coil for infrastructure and heavy roof work.

75 to 350 mm5.5 mm optionPre-cut or post-cut

View C purlin machine →

03 / Z only

Z Purlin Roll Forming Machine

Z only line for lapped roof purlins, with sag rod holes and slotted connection holes punched before the mill.

80 to 350 mmLapped spansSag rod holes

View Z purlin machine →

Multibeam purlin roll forming machine forming several beams side by side

04 / Multi strand

Multibeam Purlin Machine

Wide mill that forms several purlin beams side by side from one coil, built for plants running high volume on a narrow section range.

Multiple strandsHigh volumeSingle coil feed

View multibeam purlin machine →

The fifth layout is the multibeam mill, which forms several strands side by side instead of one. It is also offered as a general multibeam roll forming machine for other profile families. Send the section drawing and we confirm whether a multibeam layout beats several single strand lines.

Applications

Four buildings these purlins frame

A purlin is ordered for a building type, not for stock. These are the four runs most orders come from, and what each one asks of the section, the punch pattern and the purlin roll forming machine behind it.

Portal frame steel building with purlins and roof bracing during erection

01 / Industrial sheds

Portal frame factories and workshops

C purlins on the rafter line and wall girts between the columns. Cleat holes and sag rod holes are punched inline, so the frame bolts together without a drill on site.

Purlin lines for steel structure →

Warehouse clad in R panel wall sheeting fixed to purlins and girts

02 / Warehousing

Distribution centres and warehouses

Long roof runs at 1.2 to 1.5 m purlin centres, carrying sandwich panel or single skin sheet. Z purlins lap over the rafter so the run stays continuous across six bays.

The cladding these purlins carry →

Solar panel mounting structure with formed rails under the modules

03 / Solar

Mounting and tracker frames

Ground mount rows use C sections as rails under the modules. Hole pitch has to match the clamp spacing, so the punch program is set from the mounting drawing, not from a standard pattern.

Roll forming for solar trackers →

Farm building with a red metal roof on a purlin and truss frame

04 / Agriculture

Farm, poultry and machinery sheds

Wide, low buildings with a light roof load. Purlins run 1.5 to 2.5 mm galvanized at wider centres than a factory, cut to the bay length so the shed closes in a day.

Agricultural roll forming applications →

Sections off a purlin roll forming machine also turn up as mezzanine floor joists and as rails on solar trackers, both specified the same way with the hole pattern set by the connection detail. The mezzanine floor roll forming guide covers the first case in detail.

Line configuration

What a purlin line is built to

These are planning ranges. A purlin roll forming machine is quoted from the profile drawing first, then the steel grade and the output target.

Web depth	75 to 350 mm on C, 80 to 350 mm on Z
Flange width	35 to 80 mm, fixed per tooling set
Material thickness	1.5 to 5.0 mm, 5.5 mm on the heavy duty version
Coil width	Up to 500 mm, set by the developed width of the section
Forming stations	14 to 20 standard, up to 24 on heavy gauge
Line speed	10 to 15 m/min with hydraulic punch and shear, 20 to 30 m/min with servo punch and flying saw
Punching	Pre-punched coil, or an inline hydraulic press with a multi hole die
Cutoff	Hydraulic shear or flying saw, length set from the servo feeder
Drive	7.5 to 22 kW, gearbox or independent servo drive per station
Control	PLC and HMI with recipe storage for each section

Section rangeWider web and flange travel on a purlin roll forming machine needs longer shafts and more stations, which is the largest single cost line.
Thickness5.5 mm coil needs a heavier frame, bigger drive and a reinforced punch, not just a slower feed.
ChangeoverManual spacers, motorized adjustment or a cassette system change the price by a wide margin.
Hole patternEach pattern needs its own die set. Two patterns usually means two dies, not two machines.

Changeover

How fast you can switch sections

Changeover is where most plants lose money on a purlin roll forming machine. Pick the adjustment system before you pick the price.

Manual spacers

Shims and spacer rings set web and flange by hand. Lowest cost, and the slowest change, measured in hours with a two man crew.

Motorized adjust

Web and flange move on lead screws from the HMI. The same change drops to under half an hour on a well set up line.

Quick interchange

Roll packs swap as a unit. Changeover falls to minutes, at the cost of a second set of packs per section family.

Switchable C and Z

The mill turns a C section into a Z section without re-tooling the stands, so both purlin types stay in house.

Punching and cutoff

Holes decide the cycle time

Purlins are bolted, not welded. Every connection hole, slotted hole and sag rod hole has to land in the right place before the section is cut, or the frame will not assemble on site. On a purlin roll forming machine the press, not the mill, sets the cycle time.

Pre-punched coilCheapest machine, but the pattern is fixed when the coil is ordered and every run needs the same pitch.
Inline hydraulic punchBolt holes, slots and notches punched between feeder and mill, with a die change for a second pattern.
Shear or flying sawA shear gives a square end at 10 to 15 m/min. A flying saw cuts on the move and keeps a 20 to 30 m/min line running.
StackingA runout table is standard. An automatic stacker pays back on long runs of one length.

Material is usually galvanized to EN 10346 (S250GD or S350GD) or ASTM A653, in Z275 or G90 coating. Tolerances follow the section tolerance rules used in steel construction, and lines shipped to the EU arrive with CE documentation under the EU CE marking rules.

Hydraulic punch system on a C purlin roll forming machine

Questions

Purlin roll forming machine FAQ

What buyers ask before a purlin line is quoted, answered in plain terms.

What is a purlin roll forming machine?

A purlin roll forming machine is a production line that forms C, Z, U or Sigma purlins from galvanized coil. Coil is decoiled, leveled and fed through a punch press, then through 14 to 24 roll stations, and cut to length at the end. The section becomes the roof and wall framing of a steel building.

What is the difference between a C purlin and a Z purlin?

A C purlin has a flat web with two square flanges and is used where a simple span is enough. A Z purlin has flanges bent in opposite directions, so two sections nest and overlap over a rafter. The overlap makes the run continuous and carries more load on the same steel weight.

What thickness can a purlin line form?

Standard purlin machines run 1.5 to 5.0 mm galvanized coil. A reinforced version forms up to 5.5 mm for infrastructure and heavy roof work. Below 1.5 mm the section tends to twist during forming, so light gauges are usually run on a separate light gauge mill.

How fast does a purlin roll forming machine run?

10 to 15 m/min is normal when a hydraulic punch and shear are inline. With a servo punch and a flying saw the line runs 20 to 30 m/min. Real output depends on hole density, because the press, not the mill, sets the cycle on a heavily punched purlin.

Can one machine produce both C and Z purlins?

Yes. A switchable C and Z mill changes section type without re-tooling every stand, and motorized web and flange adjustment sets the size from the HMI. Changeover is minutes on a cassette design and several hours on a fixed mill with manual spacers.

How much does a purlin roll forming machine cost?

A dedicated C line with manual adjustment starts near USD 55,000. A switchable C and Z line with servo punching and a flying saw runs USD 110,000 to 180,000. Multibeam machines sit above that. On any purlin roll forming machine, section range, thickness, changeover system and the number of hole patterns move the price most.

What is the lead time for a purlin line?

Build time is 45 to 90 days after the drawing and deposit are confirmed. Sea freight adds 20 to 45 days depending on the destination port. Die sets for a second hole pattern are usually built in parallel and ship with the machine.

Next step

Send the drawing, get a line plan

Send the purlin profile, the steel grade and the output you need per shift. We size the purlin roll forming machine around those three inputs and reply with the station count, the punch and cutoff arrangement and a price range before drawing work starts.

Page reviewed 29 October 2026.

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