About Springly
In a world where everything costs money, we’re here to create a practical, free tool that modernizes the way we design and select springs.
Traditional spring selectors rely on isolated textbook equations or demand a tedious, manual trial-and-error process. Springly flips the script: you input the physical constraints and functional requirements of your assembly, and our engineering engine mathematically identifies the best off-the-shelf catalog springs for your application.
The Fastest Way to Select a Spring
Why traditional spring calculations and distributor search filters waste hours of engineering time—and how Springly solves it.
The Problem with Conventional Spring Sizing
Every mechanical engineer has experienced the frustration of manual spring lookup.
The Textbook Formula Trap
Standard textbook equations (like k = G·d&sup4; / (8·D³·N)) are forward-solving equations. They require you to already know the wire diameter d, mean diameter D, and active coil count N.
In real design work, you don't know the geometry yet—you only know your stroke length, preload force, and maximum working force!
Clunky Distributor Filters
Distributor websites force you to filter through drop-down menus: Free Length, Wire Diameter, Outside Diameter, and Spring Rate.
If you filter for a 2.00" free length, you completely miss a 2.25" catalog spring that fits your housing perfectly when pre-compressed to your installed length.
How Springly Solves It: The Inverse Search Engine
Instead of guessing dimensions, you provide the only numbers you actually know:
Installed Length & Force
Length at rest & initial retaining force.
Operating Length & Force
Length at full stroke & required return force.
Hole / Rod Constraints
Optional Max OD (hole) or Min ID (rod).
Springly immediately calculates the required spring rate (k = ΔF / ΔL), mathematically scans thousands of verified Century Spring Corp off-the-shelf catalog springs, checks solid height safety clearances, and ranks the best matches by minimal force error.
Ready to size your spring?
No sign-ups, no paywalls, and no shopping carts. Just pure, free engineering software.
Open Springly Selector →