Applications
Where this spring style fits
Review best-fit uses, assembly constraints and situations where another spring style may be a better choice.
View application guidance →Compression Springs
Custom Convex Compression Springs
Barrel-shaped compression springs with a wider middle and smaller end coils, reviewed against seat dimensions, housing clearance and working loads.
- Specification
- Drawing and working requirement
- Dimensions
- Confirmed for the assembly
- Performance
- Specified at working positions
- Quotation
- Submit dimensions and quantity
About Custom Convex Compression Springs
A convex or barrel-shaped compression spring increases in coil diameter toward its middle. Its widest section defines the housing envelope, while the smaller end coils define seating. The diameter transition is part of the design and should be shown in a side view. Any benefit in seating, travel or stability needs to be evaluated for the actual geometry and mounting conditions.
Key Design Characteristics
- Specify maximum middle diameter separately from the two end diameters.
- Show the seat or pilot that locates each end coil.
- Review coil contact and body clearance at the shortest working height.
Choosing Between Related Designs
This page covers an enlarged middle, rather than the reduced middle of an hourglass spring. A standard cylindrical coil has approximately constant body diameter. Compare installation clearance before choosing a different body shape.
Specification and Inspection Review
Request dimensional checks on the maximum body envelope and end seats, together with load checks at the agreed heights. State whether the assembly includes a guide and whether coil contact is permitted during normal use.
Product Specification
What to Define for This Spring
Use these product-specific inputs to describe your requirement. Final dimensions, material and performance are confirmed against the drawing and operating conditions.
| Specification item | What to define |
|---|---|
| Body profile | Maximum diameter, end diameters and transition locations. |
| Assembly seats | Seat diameters, locating pilots and permissible end movement. |
| Working heights | Free height and the installed height range. |
| Axial force | Load and acceptance tolerance at stated heights. |
| Material and ends | Wire size, material, end shape and surface condition. |
Next Design Decisions
Next Steps for Your Spring Design
Once the spring style is selected, confirm how it works in the assembly, which material suits the environment, how it will be manufactured and which dimensions and performance points should be controlled on the drawing.
Materials
Choose the material for the environment
Select material using load, environment and forming requirements; a barrel shape does not identify an alloy or a heat-treatment condition.
Compare spring materials →Manufacturing
Plan prototype and production
Review forming, heat treatment, secondary operations, inspection and the path from first samples to repeat production.
View manufacturing capabilities →Engineering Data
Use the engineering guide for design support
Use the engineering library to review materials, sizing considerations and applicable standards for the custom design.
Open Spring Engineering Guide →Material Direction
Common Material Families to Review
The links below are selection guides, not a claim that every grade is suitable for every size or load.
Related Spring Design Guides
Review the design and measurement requirements for this spring family.
Compare Designs
Related Spring Products
Use these alternatives when the available space, connection style, travel or force direction changes.
Compression Springs
Hourglass / Concave Compression Springs
Compression springs with a narrower waist and wider end coils, specified by the full diameter profile, working heights and required axial loads.
Compression Springs
Conical Compression Springs
A tapered compression spring for assemblies that need a changing diameter, improved stability, or a lower compressed package than a conventional straight coil can provide.
Compression Springs
Continuous-Length Compression Coils
Long compression coils for cut-to-length requirements, with the finished section, end condition and working load specified separately.
Product Questions
Convex Compression Springs FAQ
Is a convex spring the same as a conical spring?
No. A convex body widens toward its middle and narrows toward both ends. A conical body generally changes diameter from one end to the other.
Can it replace a cylindrical spring without changing the housing?
Check the widest body diameter, both seat interfaces and the full working-height range first. Similar free height does not establish interchangeability.
RFQ
Send the Working Requirement
A drawing is ideal. If you do not have one yet, provide the dimensions, load or torque, travel, environment and expected quantity that matter in the assembly.
CustomSprings Engineering Catalog
Request This Spring
Send your dimensions, quantity and drawing for engineering review.