TDF Corner Making Guide 2026: Machine vs Matics vs Molds

TDF Corners: The Weak Point of Every Duct System

Every rectangular duct section has four corners — and those corners are where air leaks happen most. Poorly formed corners mean energy waste, noise, and failed inspections. That's why choosing the right TDF corner making solution is more important than many fabricators realize.

Preda offers three corner making approaches, each suited to different production volumes and budgets.

Three Corner Making Approaches

TDF Corner Making Machine: Fully Automatic

The TDF Corner Making Machine is a dedicated automatic corner forming station. Feed the duct corner, and the machine punches and forms the corner in one operation — no manual alignment needed.

• Fastest production: 300–500 corners per hour
• Consistent quality: Every corner identical — no human error
• One operator: Load and go, minimal skill required

View Corner Making Machine →

Portable Hydraulic Corner Matics TDF-12

The Portable Hydraulic TDF Corner Matics TDF-12 is our most popular corner tool. It's a wheeled, self-contained hydraulic unit that can be moved anywhere in the shop — or even to the job site for on-site duct modification.

• Portable: Wheeled cart moves easily between workstations
• Self-contained: Built-in hydraulic pump, just plug in 220V
• Versatile: Works on TDF and TDC corners with quick-change dies
• 150–250 corners/hour: Perfect for medium-volume shops

View Hydraulic Corner Matics →

Pneumatic Corner Matics PC-12

The Pneumatic TDF Corner Matics PC-12 uses compressed air instead of hydraulic power. Ideal for shops that already have a robust compressed air system and want a simpler, lower-maintenance corner tool.

View Pneumatic Corner Matics →

Corner Molds PD-01/PD-02/PD-03: Budget Option

Corner Molds are precision-ground die sets that work in your existing shop press or arbor press. They're the lowest-cost way to get professional-quality TDF/TDC corners — simply place the duct corner in the mold and press.

• Lowest cost: Fraction of the price of powered machines
• No power needed: Works with your existing press
• Three profiles: PD-01 (TDF), PD-02 (TDC), PD-03 (G Clamp for TDC)
• Portable: Easy to store and move

View TDF Corner Mold PD-01 →

How to Choose

1. Daily corner volume? >200/day → Corner Making Machine. 100–200/day → Hydraulic/Pneumatic Matics. <100/day → Corner Molds
2. Do you need portability? Job site work or flexible shop layout → Portable Matics
3. Do you have compressed air? Yes → Pneumatic Matics (simpler maintenance). No → Hydraulic Matics
4. Budget? Starting out → Corner Molds. Growing → Hydraulic Matics. High-volume → Corner Making Machine

Three Corner Methods Compared on Cost and Quality

Corner making looks like a minor step until you pressure-test a duct run. The corner is where the two flanges meet and where the sealant path is hardest to keep continuous — which is why field testing consistently finds the majority of duct leakage at connections rather than in straight runs.

Where the money actually goes. Hand-fitted corners using the mould set are the cheapest way to start and the most expensive way to scale. At 30–60 seconds per corner and four corners per section, a manual operator spends two to four minutes per section on corners alone. A hydraulic machine does the same work in under 30 seconds. Over a 200-section shift that is roughly eight operator-hours recovered per day — which at $25/hour loaded is $200 a day, and pays for the $4,800 machine in under 25 working days.

The portable machine is not a cheap substitute — it is a different tool. Its value is on site: when an installer finds a damaged corner during installation, driving back to the shop costs hours. The TDF-12 lets one person fix it in place. Buy it for your field crews, not to avoid buying the shop machine.

Corner Fit: The Checks That Prevent Leakage Callbacks

Four checks catch almost every corner defect before the duct leaves the shop:

1. Insertion depth. The corner must seat fully into both flanges. A 2 mm shortfall leaves a step and a leak path.
2. Crimp symmetry. An uneven crimp on the hydraulic machine means the corner was not square in the die. Check on the first piece of every batch.
3. Sealant continuity through the corner. The gasket or mastic must run unbroken. Breaks here are the single most common leakage finding.
4. Diagonal measurement. Measure both diagonals of the finished duct end. A difference over 2 mm on a 600 mm section means the assembly is racked, and it will fight the installer on site.

Material matters. Corners are formed from the same galvanised or stainless as the duct. Stainless work-hardens faster than galvanised, so corner tooling wears noticeably quicker on stainless jobs — budget for tooling replacement roughly twice as often if stainless is more than a quarter of your work.

Corner Inventory Planning

Corners are consumable and size-specific. Running out of one size stops a job completely, which makes inventory planning more important than the unit price.

A practical rule: stock bought corners for the two or three sizes that make up 70% of your volume, and make the rest in-house on demand. That keeps the machine fed without tying up cash in slow-moving stock.