Find the perfect design for your snap-fit connection with the help of Snapfit

From sketch to number in seconds

At its core, the Snapfit app solves the classic cantilever-beam problem behind snap-fit design. The analytical formulas are based on established engineering references and BASF design guidelines for connections. Given few design parameters (beam's width, thickness, length, lead angle, and return angle) it can predict how much force is needed to push the joint together, how much force is needed to pull it apart, how far the beam must deflect to clear its catch, and most importantly whether the resulting strain stays safely below what the chosen plastic can handle. It supports several distinct beam geometries, based on commonly used connections types found in the industry. Depending on whatever you already know or aim for, more than ten different solving modes are available. It means that you can start from a target force, a required deflection, or a specific material's strain limit and let the tool back-solve for the rest. The app let you define versions, so you can quickly iterate and test different concepts easily for a particular design.

Built-in safety verdict

Every calculation ends with the same question: is this design actually safe to mold and use? Snapfit app answers it automatically by comparing the beam's operating strain against the material's allowable strain and returning a clear suitability verdict. The check is applied across every connection type and every solve mode, so results stay consistent no matter which starting point was used to get there.

Guidance for non-experts

Not every user arrives already knowing which of possible geometry types or solving mode they need. The app also includes a design advisor that works the other way around: describe the application in plain terms — a joint that must separate for service, one that lives in a tight, space-constrained housing, one that needs to survive frequent opening and closing — and it recommends a starting beam type, solve mode, and geometry, flags what information is still missing, and can suggest ranked design improvements against a target strain or force.

Two ways to solve: analytical and FE

In addition to classical analytical formulation from beam theory, the app offers an alternative solving finite element (FE) mode. This mode automatically builds a 3D parametric mesh of the snap connection (based on the design parameters provided), runs the structural simulation and returns displacement and stress fields. The result files can then be previewed or downloaded.

Integral part of Ultrasim® web services

The Snapfit app runs on Ultrasim® simulation platform: it means no local software to install and no manual file wrangling. Get your design question answered within seconds.

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