Use stretchers to align S-and-drive

Before you start

• Confirm the duct sections are the same size and the obstruction is alignment—not fabrication error.
• Inspect all four lock edges for damage.
• Support both pieces at the correct elevation before applying force.

Lay it out

1. Identify which side or corner is open and why.
2. Check hanger elevation, section twist, reinforcement, and nearby fittings before using the stretcher.
3. Choose attachment points close to the side lock without hooking weak panel centers.

Set and support it

1. Stabilize the installed section.
2. Hold the loose section level and square.
3. Use clamps at other corners if needed to prevent the stretcher from rotating the duct.

Make the connection

1. 1

   Engage the top and bottom S-cleats as far as possible by hand.

2. 2

   Hook the stretcher securely on sound metal near the joint.

3. 3

   Pull the side edges together gradually while watching the opposite corners.

4. 4

   Start the drive as soon as the lock is correctly aligned.

5. 5

   Seat the drive while maintaining only enough stretcher pressure to hold alignment.

6. 6

   Release the stretcher slowly and verify the duct stays square.