BS 8726-1:2002

Foreword
1 Scope
2 Normative references
3 Terms, definitions and symbols
4 General
5 Methods of calculation
6 Tolerances
7 Specifying springs for general purposes
8 Methods of verification
Annex A (informative) Modulus of rigidity of some materials
Annex B (informative) Typical tolerances on rectangular
        section material
Figures
Tables

Gives guidance on the design of parallel sided helical compression springs manufactured from rectangular and square section wire and bar. It applies only to springs made from rectangular section material where the ratio of radial dimension, to the axial dimension, is upto 2.5 and not less than 0.4.

This British Standard provides guidance on the design of parallel sided helical compression springs manufactured from rectangular and square section wire and bar.

This standard applies only to springs made from rectangular section material where the ratio of radial dimension, b, to the axial dimension, h, termed the shape factor, m, is not greater than 2.5 and not less than 0.4.

NOTE1 This applies because, outside the shape factor range 2.5 to 0.4, it is difficult to coil a spring accurately.

NOTE2 There are numerous methods of calculating the parameters necessary for the design of springs and initially the designer is free to use any one of these.

Three types of end coils are provided for, i.e. open end, closed end and closed and ground end, the last of these being applicable only to springs where the axial dimension of material is 0.5mm or greater.

This British Standard differentiates between springs that have or have not been stress relieved after forming, designated group A springs, and springs, the material of which has undergone a structural change by heat treatment after forming, designated group B springs.

This British Standard gives two methods of specifying springs for general purposes and one method of testing springs.