# Spring Design :How to achive a given spring constant k

1. Sep 2, 2011

### PtrElectron

Dear experts,

I would like to know the formula to achive a given spring constant
for example 10.90 N/m. or is there any url where I can
get the source code, which can take the spring constant
as input and provide the different options/ parameters
to achive the same. Please execuse me if, it is a very basic question.

-Electron

2. Sep 2, 2011

### olivermsun

By "formula" do you mean a recipe for making such a spring?

Or are you asking for a mathematical formula for relating force to displacement through a spring constant, e.g., http://en.wikipedia.org/wiki/Hooke%27s_law" [Broken]?

Last edited by a moderator: May 5, 2017
3. Sep 2, 2011

### PtrElectron

Sir, Thanks a lot for the responce. I understood that

spring constant k = (Gd4)/(8D3 na)

and where G is found from the material's elastic modulus E and Poisson ratio v,

G = E/2(1+v)

and can you please advice where I can get the E and v values of materials and where I can find more details in this reagrd.

If I want to acheive the G some 81400 N/mm2, which is the best meterial to opt to design my spring. or is that I need to option for combination of certail meterial.

Many Thanks