- Client view: parts click together with an audible “snap”, no tools.
- Engineering view: geometry tuned for deflection, pull-off load and number of cycles.
Locking Joint Variants
JOINT DESIGN REFERENCE
Locking Joint Variant Chart – Sheet & Plastic Parts
This page summarizes 30 cross-sectional joint profiles. They are intended as a concept library for engineers and customers discussing how two components can snap, hook, clamp or hinge together.
The variants are arranged in five rows of six. Within each row, reading order is left to right: joints 1–6, then 7–12, and so on up to 30.
Use the filter bar and the category schematics below to quickly focus on hooks, clamps, hinges, cams or more complex locking features.
How to read the schematic
- The lower block represents the fixed base or mating component (sheet metal flange, plastic housing, machined boss, etc.).
- The upper slender shape is the moving part or punch forming the joint. The thick dark line shows the deformed sheet / rib.
- Joints are normally assembled in the arrow direction (push-in or snap-in) and resist the opposite pull-off direction.
- Sketches are not to scale – final geometry depends on material, thickness, tolerances and loads.
Category schematics – quick view for engineers and customers
Each tile below shows a simplified cross-section of a joint family. Click a tile to filter the table to that category. The notes explain it in client language and highlight the engineering focus.
- Client view: joint aligns parts and holds them tightly in position.
- Engineering view: reference surfaces; key points are tolerance stack-up and contact pressure.
- Client view: one part “sits inside” the other with side support.
- Engineering view: defines position in X/Y/Z; often combined with screws, staking or adhesive.
- Client view: small built-in hinge / pivot.
- Engineering view: check minimum bend radius, wear and assembly (open vs. closed curl).
- Client view: closing movement pulls parts together and preloads a seal or joint.
- Engineering view: cam angle controls force amplification and closing effort.
- Client view: joint blocks movement in several directions at once.
- Engineering view: used where safety or vibration require redundancy in the lock.
Joint variants with categories and design intent
Use the filters or click a category tile above to show only a certain family of joints. Categories are indicative and several joints can fit more than one category.
| No. | Short name | Category | Function & notes |
|---|---|---|---|
| 1 | Simple hook tab | Hookone-way snap | Primary lock in vertical pull-off direction. Short hook under a shoulder; easy to mold and form. Best for light to medium loads, plastic housings or thin sheet. |
| 2 | Deep hook tab | Hookincreased retention | Longer vertical leg increases engagement length and pull-off strength. Use where the joint must not release unintentionally but tool access is limited. |
| 3 | Multi-step hook | HookComplex | Z-shaped hook with several steps; difficult to disengage without deformation. Near-permanent joint; good where tamper resistance is required. |
| 4 | Straight V-wedge | Clamp | V-shaped wedge that centers and clamps the mating edge. Self-locating; loads mainly compressive. |
| 5 | Long lever hook | Hookflexible arm | Long arm provides elastic travel and controlled snap-in. For covers that need to be opened repeatedly without tools. |
| 6 | Wave spring latch | Cam / spring | Wavy contact at the base works as an integrated spring. Provides soft tactile feedback and tolerance compensation. |
Application notes
The profiles shown are concept sketches. Before releasing a production design, each joint is adapted to:
- material (steel, aluminum, stainless, ABS, PC/ABS, etc.),
- thickness and forming process (stamping, laser + forming, molding),
- required load and safety margin,
- tolerances, assembly method and tool access.
We can review your 3D models or sketches and recommend the most suitable joint variant from this library – or a combination of them – tailored to your application.
- Covers & doors
- Electronics housings
- HVAC & ducting
- Automotive trim
- Enclosure hinges
- Tool-free assembly