What is the primary application of a rat-tail door spring?

It is used primarily on lightweight internal wooden doors and wire-gauge (screen) doors to ensure they close automatically.

What material is required for the spring coil?

High carbon spring steel wire conforming to IS 4454, which maintains the required tension over repeated open/close cycles.

How is the size of the rat-tail spring designated?

It is typically designated by its overall length and the diameter of the spring wire used.

IS 452

: 1973

Door Spring, Rat-Tail Type - Specification

CurrentRareSpecificationArchitectural · Builder Hardware

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This standard specifies the requirements for materials, dimensions, manufacture, and finish of rat-tail type door springs. It is used by builders and quality inspectors to ensure reliable automatic closing mechanisms for lightweight wooden or screen doors.

Door Spring, Rat-Tail Type - Specification

Quick Reference Values

Typical overall length200 mm to 300 mm depending on size

Spring wire materialSpring steel conforming to IS 4454

Fixing plate materialMild steel sheet conforming to IS 1079

Finish requirementStove enamelled, galvanized, or electro-plated to prevent rust

Practical Notes

Rat-tail door springs are largely obsolete in modern heavy doors but are still used for lightweight wire-mesh (mosquito) doors and budget residential builds.

Pay special attention to the protective finish (galvanization or paint) as the spring steel is highly susceptible to corrosion, which leads to squeaking and failure.