Terminology Common to All Springs   

• Active Coils – The coils which are free to deflect when the spring is loaded.
• Total Coils – All coils including the end coils.
• Counting Coils – Look at the end of the spring, turn the spring the wire is at 12.00 o’clock, follow the wire round, each time the wire passes 12.00 o’clock it is a complete coil, when reaching the last full coil stop and estimate the remaining wire ie, ¼, ½ or ¾ etc. then add this to the number of full coils.
• Spring Hand – The direction in which the spring is wound, Right or Left Hand.
• Right of Left Hand – Look at the end of the spring, turn the spring so the start of the wire is at 12.00 o’clock, if the direction of the wire is to the right the spring is Right Hand (R/H), if the direction of the wire is to the left the spring is Left Hand (L/H).
• Mean Coil Diameter – Outside spring diameter (O/D) less one wire diameter.
• Deflection – Movement of ends of spring when a load is applied.
• Rate – Change in load per unit deflection, normally given as pounds per inch (lbs/in) or Newton’s per
• millimetre (N/mm).
• Load – Pressure at a given deflection.

Terminology Specific to Compression Springs 

• Free Length – The overall length of a spring in the unloaded position.
• Pitch – The centre of wire to the centre of wire of adjacent active coils (best practice is to specify active or total coils).
• Ends Closed – Where the end of spring pitch is reduced so the end coils touch.
• Closed and Ground Ends – As Ends Closed but ground square for more stable location.
• Solid Height – Compressed length of a spring, when all the coils are touching with no spaces between

Terminology Specific to Tension Springs

• Pull to Pull – The measurement between inside the wire hooks/loops at the end of the tension spring.
• Hooks – Cut loops to form a hook for attaching spring to location.
• Loops – Spring end coils lifted up from body of spring to form full loops for attaching spring to location.
• Initial Tension – The pressure that keeps the coils of an extension spring together and must be overcome before the coils will open.

Terminology Specific to Torsion Springs 

• Free Angle – Angle between the legs of a Torsion Spring when there is no load applied. 
• Torque – A twisting action in torsion springs which produces rotation, equal to the load multiplied by the distance (or moment arm) from the load to the axis of the spring body.

Frequently Asked Questions

Do springs get weaker overtime?
Yes, springs do weaken over time as a result of repeated use, high loads, and exposure to harsh environmental conditions, which can lead to loss of elasticity and reduced performance; however, proper maintenance and choosing high-quality, appropriately rated springs can help mitigate wear and prolong their effective lifespan.

What springs won’t rust?
Springs made from stainless steel or specialized alloys like phosphor bronze or Inconel are highly resistant to rust and corrosion, making them ideal for use in harsh or wet environments; these materials ensure long-lasting durability and reliable performance, even under challenging conditions.

Do springs get weaker overtime?
The four main types of springs are compression springs, which resist force when compressed; tension springs, which resist pulling forces when stretched; torsion springs, designed to store rotational energy; and die springs, built for heavy-duty applications under high loads. Each type is tailored for specific functions across various industries, including automotive and industrial manufacturing, providing reliable solutions for different mechanical needs.

What are most coil springs made of?
Most coil springs are made of high-tensile steel, prized for its strength, flexibility, and resistance to wear; to further enhance durability and performance in various applications, this steel is often subjected to treatments like heat treatment or coating, ensuring reliable and long-lasting operation

What are the strongest springs made of?
The strongest springs are typically die springs, engineered to withstand extremely high loads and frequent cycles, making them suitable for heavy-duty industrial applications; crafted from durable materials like high-tensile steel or rectangular wire, they offer exceptional strength and durability under intense pressure.

What are the three most popular types of springs?
The three most popular types of springs are compression springs, which resist compressive forces in machinery and vehicles; tension springs, which stretch to absorb and store energy; and torsion springs, designed for rotational movement in devices like hinges and clocks. These versatile springs are widely used across industries owing to their adaptability, reliability, and effectiveness in various mechanical applications.