Gardner Spring 429C Extension Spring 0.625in Od 21.1lb

Product Description

The GARDNER SPRING 429C is a steel extension spring designed for applications requiring consistent tensile force across a defined range of travel. It features a 0.625 inch outside diameter, a 0.072 inch wire diameter, and a spring rate of 1.52 lb/in. At maximum extension, the spring reaches 21.1 inches with a corresponding maximum work load of 21.1 lb. The overall free length is 12.0 inches. A zinc-plated finish provides basic corrosion resistance for use in light-duty industrial, mechanical, and HVAC-related assemblies. Double loop ends allow for straightforward attachment to mounting hardware in typical spring-loaded mechanisms.

This extension spring is suited for residential and light commercial applications where a compact-diameter coil spring is required to return a component to its resting position or apply tension across a mechanical linkage. Common install scenarios include damper actuators, door assemblies, counterbalance mechanisms, and equipment panels in HVAC and related trade equipment. It is sold in a package quantity of three units, which supports stocking for service calls or multi-unit jobs.

Key Features

• 0.625 inch outside diameter for use in standard compact spring pockets
• 1.52 lb/in spring rate for predictable, linear load response
• 21.1 lb maximum work load at 21.1 inches maximum extended length
• 12.0 inch free length provides substantial working travel
• Double loop ends for easy attachment to pins, hooks, or brackets
• Zinc-plated steel construction for basic corrosion resistance

Compatibility

Designed as a standard-geometry extension spring for use in mechanical assemblies requiring a 0.625 inch OD coil spring with double loop ends. Confirm spring rate, free length, extended length, and wire diameter against the application requirement before installation.

Installation Notes

Extension springs should be installed by a qualified technician familiar with the mechanical assembly being serviced. Relieve all tension from the system before removing or installing springs to prevent snap-back injury. Verify that hook and loop ends seat fully in their mounting points before restoring load. Do not stretch the spring beyond its rated maximum extended length, as permanent deformation or failure may result.