Torsion Spring Calculator

Torsion springs are essential components in a wide range of mechanical systems from garage doors to industrial machines. But understanding and calculating their specifications can be overwhelming without the right tools. That’s why we’ve created a Torsion Spring Calculator that anyone can use no engineering degree required.

Whether you're a DIY enthusiast fixing a garage door or an engineer working on a custom application, this tool helps you calculate spring rate, torque, angular deflection, and bending stress in just seconds. Plus, it's available online no Excel or PDF downloads needed.

What is a Torsion Spring?

A torsion spring is a type of mechanical spring that stores energy by twisting. Unlike compression or extension springs, torsion springs exert a torque or rotary force. They're widely used in applications like garage doors, clothespins, vehicle suspensions, and industrial equipment.

Understanding the specifications of your spring such as wire diameter, mean diameter, number of coils, and modulus of elasticity is key to safe and effective use. And that’s exactly what our calculator helps you with.

How to Use the Torsion Spring Calculator

Step-by-step Instructions:

1. Enter the wire diameter – You can select units like mm, inch, or cm.
2. Input the mean coil diameter – This is the diameter measured from the center of the wire across the coil.
3. Type in the number of active coils – Active coils are the ones that actually twist and contribute to the spring's performance.
4. Select material or enter a custom modulus of elasticity – This value affects how much the spring twists under torque.
5. Choose your calculation type – You can either calculate based on applied torque or based on angular deflection.
6. Enter either the torque or angular deflection – The calculator will use this to compute the rest.
7. Add yield strength and safety factor (optional) – This is useful for stress and safety analysis.

Once you fill in the fields and click calculate, you’ll instantly get:

• Spring Rate (k)
• Torque (T)
• Angular Deflection (θ)
• Bending Stress (σ)
• Spring Index (C)
• Stress Correction Factor (K)

Torsion Spring Calculation Formulas

Here are the core formulas used in our calculator:

• Spring Rate (k):
  k = (E × d⁴) / (10.8 × D × N)
• Torque (T):
  T = k × θ
• Angular Deflection (θ):
  θ = T / k
• Bending Stress (σ):
  σ = (32 × T × K) / (π × d³)
• Spring Index (C):
  C = D / d
• Stress Correction Factor (K):
  K = (4C² - C - 1) / (4C(C - 1))

Where:

d = Wire diameter

D = Mean coil diameter

N = Number of active coils

E = Modulus of elasticity

θ = Angular deflection in radians

T = Torque in N-mm

These formulas help you get precise values and ensure your spring design is safe and effective.

Final Verdict

Our torsion spring calculator makes it incredibly easy to calculate important spring parameters with minimal effort. It’s designed for garage torsion springs, spiral springs, square wire springs, and more. The tool is accurate, beginner-friendly, and doesn't require any installation.

Forget downloading complicated Excel sheets or searching for PDF guides. With just a few clicks, you’ll get everything you need torque, angle, stress, and safety checks all in one place.

Try our calculator today and take the guesswork out of spring design!

FAQs

How do I figure out what torsion spring I need?

You’ll need to know the wire diameter, mean coil diameter, number of coils, and the type of material. Our calculator helps you analyze all these parameters to find the right spring.

How to calculate torsion springs manually?

You can use formulas involving wire diameter, spring index, modulus of elasticity, and applied torque. But it's easier and more accurate to use our free online calculator.

How many times do I wind my torsion spring?

The number of turns depends on the size and weight of the door or system it supports. For example, a standard 16-foot garage door usually requires about 7.5–8 turns.

Is your calculator suitable for garage door springs?

Yes, it's perfect for garage torsion spring calculations. Just enter the known values, and it gives you torque, turns, and stress checks instantly.

Can I download this tool as Excel or PDF?

Our tool works entirely online for convenience. But you can easily copy the results and save them if needed.