A 'G' fin tube (also known as an embedded fin tube) is a type of extended-surface heat transfer component where fins are externally attached to a base tube. The design involves continuous grooves formed along the base tube, into which fin edges are inserted. Following insertion, a set of rollers backfills the grooves, securely embedding the fins into the tube to create a robust mechanical and thermal bond.

Fin-to-Tube Bond Strength Testing
The integrity of the embedding process—commonly referred to as the fin-to-tube bond—is validated through a standardized test:
A 3-kilogram free weight is suspended from an isolated fin.
This test ensures the fin is properly embedded, verifying that the mechanical bond can withstand operational stresses and maintain thermal efficiency.

Technical Specifications and Key Features
Groove Formation: Precision machining creates uniform grooves along the base tube, ensuring consistent fin placement.
Roller Backfilling: The post-insertion rolling process compresses the tube material around the fin, eliminating gaps and maximizing heat transfer.
Bond Reliability: The 3 kg weight test simulates real-world vibration and thermal expansion forces, confirming long-term durability.