Fabrication Techniques Flashcards

What is the primary advantage of using a plasma cutter over tin snips for cutting sheet metal?

Answer: Plasma cutters can cut faster, handle thicker material, and produce cleaner cuts on complex shapes

Plasma cutters offer significant advantages in speed, cutting capacity (much thicker materials), and the ability to cut complex curves and shapes with clean, narrow kerfs and minimal distortion.

What is a 'TDC' (Transverse Duct Connector) flange?

Answer: A factory-formed flange integrated into the end of a rectangular duct section for bolted connections

TDC flanges are roll-formed directly onto the ends of rectangular duct sections, creating a built-in connection flange. Sections are joined using corner brackets and bolts, creating rigid, airtight joints.

What is the function of a 'clinch' or 'button punch' snap lock in duct fabrication?

Answer: To mechanically fasten overlapping sheet metal layers by deforming the metal to create a permanent connection

A clinch or button punch creates a permanent mechanical fastener by deforming two overlapping layers of sheet metal together. It replaces screws or rivets for certain applications.

What is the proper method for straightening a warped piece of sheet metal?

Answer: Use a mallet on a flat surface, working from the edges toward the high spots

Warped sheet metal is straightened by placing it on a flat surface and using a mallet to work the high spots down, working from the outer edges toward the center of the distortion.

What is the minimum recommended edge distance for rivets in sheet metal?

Answer: Two to three rivet diameters from the edge

The minimum edge distance for rivets is typically two to three times the rivet diameter. Placing rivets too close to the edge can cause the metal to tear out under load.

What is the difference between a 'Ductmate' flange and a TDC flange?

Answer: Ductmate flanges are separate roll-formed sections attached to the duct end, while TDC flanges are integral to the duct

Ductmate flanges are separate roll-formed channel sections that slide onto and are attached to the duct end. TDC flanges are formed directly from the duct metal itself as an integral part of the duct section.