When designing a tension spring, there are many factors to consider beyond the visual style of the end. Spring rate, how loads are measured at specific lengths, and the tolerances

required for the application all influence how the spring will behave in its final assembly. These characteristics work together to create consistent, reliable performance

Alongside these core parameters, choosing the right tension spring end type is an equally important step in achieving high-performance spring behaviour. In most tension spring design projects, two main considerations guide the decision: fit and function.

Fit

• A gap in the loop is needed if the end must pass through a hole or slide over a mating part
• A fully closed loop is best when the spring needs to stay fixed on a bolt or peg
• Loop orientation and centrality matter in tight or precise assemblies
• Crossover (English) loops give strong central positioning
• Precision-formed machine loops (German) can achieve the same when specified correctly
• Extended or side loops help with complex assemblies or limited space
• The best option depends on the surrounding components and intended motion

Function

• Ends are the weakest point as they are formed from the final coil
• Coned ends help reduce stress and increase spring life
• Separate coned-in hooks, bolts or attachments can remove the stress point entirely
• This improves durability and performance in demanding environments

As a UK spring manufacturer specialising in precision tension springs, JB Springs frequently collaborates with designers and engineers to optimise end types, improve product reliability and streamline the overall spring engineering process. If you are working on a new design or need expert advice on choosing the most suitable spring end, get in touch today and speak to a Springtellectual. Our team is always happy to help.

Watch our video below