Round Duct Lock Former SA-12C
Last updated: October 14, 2026
Specialized lockforming machine for round duct longitudinal seams, producing airtight connections. Forms the Pittsburgh lock seam on rolled round duct sections — the round-duct counterpart to the rectangular lockformer.
Technical Specifications
What is a Round Duct Lock Former SA-12C?
A round duct lock former forms the Pittsburgh lock seam that closes the longitudinal edge of a rolled round duct section. The rolled sheet edges pass through forming rollers that create the interlocking seam profile — an airtight mechanical joint made without welding. It is the round-duct equivalent of the rectangular Pittsburgh lockformer, sized to the diameters round duct production actually runs.
Key Features
- Forms Pittsburgh lock seams on round duct longitudinal edges
- Duct diameter range 100-1200mm — the standard spiral/round range
- Handles 0.5-1.2mm material at 10 m/min
- GCr15 bearing steel rollers for long service life
- Produces airtight mechanical connections without welding
Closing Round Duct Seams by Hand or Paying for Welded Pipe?
Hand-closing a round duct seam is slow and inconsistent, and every joint is a leak risk. Welded pipe solves the leak but costs more per metre and ties you to supplier diameters.
The SA-12C rolls the Pittsburgh lock seam onto the duct edge at 10 m/min — a mechanical airtight joint, made in-house, at any diameter from 100 to 1200mm.
How It Transforms Your Production Line
The Round Duct Lock Former SA-12C works on a proven principle — here is the step-by-step workflow that makes it possible:
Edge Preparation
The rolled duct section edges are presented to the forming rollers — the seam profile is formed into the edge.
Seam Forming
Driven rollers form the lock seam profile along both duct edges in one pass.
Lock Closing
The formed edges are interlocked and closed — the mechanical seam is set.
Section Out
The closed duct section exits ready for flanging or fitting attachment.
Technical Specifications & Performance Data
Every specification on this machine is chosen for a reason. The table below shows not just the numbers, but what each one means for your daily production:
| Parameter | This Machine | What It Means for You |
|---|---|---|
| Control System | Mechanical roller drive | Consistent, repeatable operation with minimal operator training |
| Construction | Heavy-duty steel frame | Vibration-free operation, 10+ year service life |
| Certification | CE certified | Meets European safety and quality standards |
| Warranty | 2 years | Peace of mind with comprehensive factory warranty |
Problems Solved: Before vs. After
We asked HVAC fabricators about their biggest production headaches. Here is how this machine directly addresses each one:
| Without This Machine | With This Machine |
|---|---|
|
✕ Hand-closed seams
Manual seaming is slow and leak-prone |
✓ Roller-formed seam
Consistent airtight lock seam at 10 m/min |
|
✕ Welded pipe cost
Bought welded pipe costs more and limits diameters |
✓ In-house lock forming
Any diameter 100-1200mm from your own coil |
|
✕ Seam inconsistency
Hand-seamed joints vary in strength and tightness |
✓ Formed profile
Repeatable seam geometry section after section |
|
✕ Roller wear
Soft rollers deform and need frequent replacement |
✓ GCr15 bearing steel
Hardened rollers for long service life |
Where It Fits in Your Factory
This machine is versatile enough to serve multiple production scenarios. Here are the most common configurations our customers use:
Spiral Duct Fabricators
Close the longitudinal seam of rolled round duct without welding.
Round Duct Production Lines
The seam station between rolling and flanging in a round duct cell.
Cost-Focused Shops
Airtight mechanical seams at a fraction of welded pipe cost.
Full Diameter Range
100-1200mm covers the standard spiral and round duct range.
Frequently Asked Questions
Click each question to see the answer. These are the questions our sales engineers hear most often:
Professional Packaging & Global Shipping
Every machine is professionally packaged and secured in a container for safe delivery to your port. We send you loading photos before the ship sails.
Calculate Your Return on Investment
Based on average industry data, here is what a typical customer saves after installing this machine:
* Figures based on average customer data for a shop producing 100-500 bends per day. Your actual results will vary based on production volume, labor rates, and current efficiency levels. Contact our engineers for a customized ROI calculation based on your specific operation.
Ready to Upgrade Your Electric Production?
Get a customized quote within 24 hours. Our engineers will help you configure the right machine for your specific production requirements.
WhatsApp / WeChat: +86-18355321923 | Email: jason@predamachine.com
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Buying Guides for This Machine Type
Before you request a quote: how this machine class compares, what it costs, and how to size it for your production volume.
Seam Locker Buying Guide
Seam closing machines compared — Pittsburgh lock closers, pneumatic lock seamers and welders.
Read the guide → Buying GuideSpiral Duct Machine Buying Guide
Tubeformer selection with the seam and fitting stations that complete a round duct line.
Read the guide → GuideRound Duct Fittings Guide
Fittings, flanges and joint practice for round duct systems.
Read the guide →
