By Iris Xu, Sales Engineer at ZTRFM | Last Updated: September 15, 2026
Short answer: Both are purlin roll forming lines, and both can change between sections — the difference is how many sections and how you change them.
- A CUZ line runs C, U and Z on one machine with automatic C–Z width changeover driven by a PC/servo system; a documented CUZ line runs 1.0–3.0 mm galvanized coil (Q195/Q235/Q345), C/U web 80–300 mm, Z web 120–300 mm, with three pre-punch stations forming 14.3 × 25.4 mm ellipse holes, fed by a 6 t hydraulic decoiler and running on 220 V / 60 Hz as standard.
- A CZ auto-changeover line is the high-output workhorse for C and Z only: a documented line carries a dual-head hydraulic decoiler (6 t/head, 12 t total), 20 forming stands (Cr12, HRC 58–60), three hydraulic pre-punch stations, a 42 kW servo host at up to 32 m/min (normal 12–18 m/min), gauge 1–3.2 mm (Q235/Q355 HR or GI) on 380 V / 50 Hz, with a C↔Z set change of about 90–120 seconds via the HMI recipe.
Choose CUZ if your market also buys U sections (truss chords, framing, tracks) and you want one machine to cover three sections. Choose CZ if C and Z cover your catalogue and you want higher output per machine with dual-head coil loading.
Why the names confuse buyers
"CZ" and "CUZ" describe which sections one line can make, not two brands of the same machine:
| Name | Sections | Meaning |
|---|---|---|
| C | C only | Fixed C sections; tooling change for size |
| Z | Z only | Fixed Z sections; asymmetric tooling |
| CZ | C + Z | C↔Z changeover on one line |
| CUZ | C + U + Z | C, U and Z on one line with auto C–Z width change |
The letter after the first two is what you are actually buying: an extra section capability, and the changeover mechanism behind it.
Side-by-side: documented CUZ vs CZ configurations
| Item | CUZ auto-width line | CZ auto-changeover line |
|---|---|---|
| Sections | C, U and Z — one line | C and Z |
| Gauge / grade | Galvanized steel 1.0–3.0 mm · Q195/Q235/Q345 | 1–3.2 mm · Q235/Q355 HR or GI |
| C/U web | 80–300 mm | (per drawing; width ≤600 mm coil) |
| Z web | 120–300 mm | (per drawing) |
| Changeover | Automatic C–Z width changeover, smart PC + servo | Auto recipe + flange-angle adjustment on the Z lip, ~90–120 s via HMI |
| Punch | 3 pre-punch stations · ellipse 14.3 × 25.4 mm (9/16 × 1 in) | Hydraulic pre-punch 3 stations |
| Decoiler | 6 t hydraulic · ID 450–550 mm | Dual-head hydraulic 6 t/head (12 t) · ID 450–550 · OD 1730 mm · brake · electric rotate |
| Forming | (auto-width stands) | 20 stands · Cr12 HRC 58–60 · shafts 40Cr Φ90/75 · chain drive |
| Drive / speed | — | Servo host 42 kW · high 32 m/min / normal 12–18 m/min |
| Cut | (post-cut) | Pre-punch then post-cut with punch assist · cut+punch 15 kW · 300 L tank |
| Power | 220 V / 60 Hz / 3φ (other voltages on request) | 380 V / 50 Hz / 3φ |
| Outfeed | 3 m tables × 2 | 6 m table · inkjet marking · Xinje PLC · ZH/EN UI |
| Extras | U anti-drift locators, remote assist, full guards | Leveling 3-up/4-down plated shafts, emboss rolls optional |
Read the two columns as different jobs, not different quality. The CUZ line trades per-machine speed for section coverage; the CZ line trades section coverage (no U) for output and coil-loading throughput.
What U actually buys you
U sections (channel without the C's inward lips, or with anti-drift locators) show up in:
- Truss chords and framing members in some building systems
- Eaves and edge detailing where a plain channel seats better than a C
- Tracks and framing where the section is used as a receiver rather than a loaded purlin
U is easier to form than Z, but it is not identical — U profiles are prone to drift in the line, which is why the documented CUZ line ships U anti-drift locators as standard and films them during changeover. If your orders include U, saying "we make C and Z" in an RFQ will get you the wrong machine.
Changeover: the number that decides your cost per order
Changeover time is where purlin machines quietly win or lose money:
| Configuration | Typical C ↔ Z (or size) change |
|---|---|
| Auto-changeover with HMI recipe | ~90–120 seconds (documented CZ process line) |
| Quick-change with swing-in roller sets | ~20–30 minutes |
| Manual tooling swap | 1–3 hours |
Published figures differ because the mechanisms differ — an HMI-recipe auto-changeover line is not the same product as a machine where an operator unbolts stands. Always ask which mechanism your quotation includes, then multiply the changeover time by your real number of changes per day. On a shop changing C/Z twice a day, the difference between 2 minutes and 3 hours is measured in months of lost output per year.
Power and site requirements
A frequently overlooked difference: documented CUZ lines run 220 V / 60 Hz / 3φ as standard (aimed at 60 Hz markets), while documented CZ changeover lines run 380 V / 50 Hz / 3φ. Both can be specified to other voltages on request — but you must state your site voltage in the RFQ, because the servo host, hydraulics and control transformer are all built around it.
Which to buy: decision table
| Your situation | Recommended | Why |
|---|---|---|
| You sell C and Z purlins only, medium–high volume | CZ auto-changeover | Dual-head decoiler + 20 stands + 32 m/min class output |
| Your orders include U as well as C and Z | CUZ auto-width | One line covers three sections; U locators standard |
| You change sections several times per shift | Either — but confirm HMI/auto changeover | 90–120 s per C↔Z change vs hours on manual tooling |
| You are in a 60 Hz market | CUZ (220 V/60 Hz) or specify voltage on a CZ | Documented CUZ is 60 Hz-native |
| You need heavy structural thickness beyond 3.2 mm | Neither | Purlin lines top out around 3–3.2 mm; move to a structural line |
| Low volume, single section | C-only or Z-only machine | Cheaper; quick-change capability unused |
7 questions to ask before choosing CUZ or CZ
- Which sections must the line make — C, U, Z, or all three?
- What is the changeover mechanism (auto recipe / hydraulic quick-change / manual), and the documented time per change?
- What gauge band is guaranteed for each section, including high-strength grades (Q355)?
- What punch configuration — 3 pre-punch stations, hole pattern, and does it match my drawing (e.g. 14.3 × 25.4 mm ellipse)?
- Decoiler type and coil window — single head, dual head, ID/OD limits, coil weight?
- Site voltage and frequency — is the quotation built for my power supply?
- What outfeed and marking is included (table length, inkjet marking)?
Where to see the real CUZ and CZ lines documented
- C/U/Z Purlin Auto-Change Forming (ZTRFM Process Library) — 1–3 mm, C/U 80–300, Z 120–300, 3 ellipse punches, 6 t decoiler, 220 V/60 Hz
- C/Z Purlin Auto-Changeover Forming (ZTRFM Process Library) — dual-head 12 t, 20 stands, 42 kW servo, 32 m/min, 90–120 s changeover
- Fully Automatic CZ Purlin Roll Forming Machine (ZTRFM product page)
- Automatic C & U Purlin Roll Forming Machine, Dual Profile Line (ZTRFM)
- Purlin / Channel / Beam process library (ZTRFM)
- Purlin Roll Forming Machine: Complete Buyer's Guide (ZTRFM) — price bands and cross-machine comparison
ZTRFM (zt-rfm.com) is a roll forming sourcing center operated by Zhongtuo Roll Forming (Hebei) Co., Ltd.
Frequently Asked Questions (FAQ)
Is a CUZ machine better than a CZ machine?
Neither is better — they solve different problems. CUZ makes C, U and Z on one line with automatic width changeover; CZ makes C and Z with higher output and a dual-head decoiler.
Can a CZ machine make U sections?
The documented CZ auto-changeover line is specified for C and Z with flange-angle adjustment on the Z lip. If U is in your catalogue, specify a CUZ line rather than assuming a CZ can be adapted.
How long does a C↔Z change take?
On an HMI-recipe auto-changeover line, about 90–120 seconds. On quick-change swing-in tooling, roughly 20–30 minutes. On manual tooling swaps, 1–3 hours. Ask which mechanism your quote includes.
What thickness can these lines run?
The documented CUZ line runs 1.0–3.0 mm galvanized (Q195/Q235/Q345); the documented CZ line runs 1–3.2 mm (Q235/Q355, HR or GI).
Why does the CUZ line show 220 V / 60 Hz?
Because it is built for 60 Hz markets as standard. Other voltages can be specified — but tell the supplier your site power in the RFQ.
What holes do these lines punch, and when?
Both documented lines use pre-punch stations before forming — three stations, with the CUZ forming a standard 14.3 × 25.4 mm (9/16 × 1 in) ellipse. Pre-punching on the flat strip is more accurate than punching after forming.
Can one line cover C, U and Z and also do heavy structural sections?
No. Purlin lines are typically limited to around 3–3.2 mm; heavier sections require a structural roll forming line.
