CNC Spring Coiling Machine Selection by Type and Diameter

Start with the spring drawing

Specify wire diameter, material grade and condition, outside or inside diameter, free length, coil count, pitch and end configuration. Add tolerances and identify the dimensions that control assembly. For springs defined by performance, provide load at specified lengths or torque at specified angles as applicable.

Jinchun's existing spring-making machine selection guide introduces equipment selection. This article adds drawing-level checks and finished-spring verification so a quotation can be tied to actual parts rather than a broad machine category.

Compression extension and torsion springs

Compression springs need control of coil geometry, pitch and end condition. Extension springs introduce hooks or loops and may have an initial-tension requirement. Torsion springs require controlled leg geometry and angular relationships as well as a suitable coil body.

Ask which operations are completed in the proposed machine and which require separate equipment. A machine that forms a coil body may still need additional tooling or another process for hooks, end grinding or special legs. Demonstrate the complete spring rather than an unfinished coil.

Wire diameter and material strength

Provide the material specification and condition for each diameter. Different wire strengths and surface conditions can change forming load, tool wear and feeding behavior. A nominal maximum diameter should therefore be confirmed for the material actually purchased.

Do not combine the most favorable numbers from different product tables. For each candidate, request one current configuration sheet listing the material-specific range, tooling, control functions and demonstrated spring examples. Keep that sheet attached to the quotation and trial report.

Spring outside diameter and spring index

For a round-wire helical spring, mean coil diameter equals outside diameter minus wire diameter. Spring index is mean coil diameter divided by wire diameter. It describes how tightly the wire is coiled relative to its thickness; it is not a machine capability rating on its own.

For example, a hypothetical 2 mm wire spring with 16 mm outside diameter has 14 mm mean diameter and an index of 7. This is a geometry example, not a recommended design or Jinchun capacity claim. The supplier still needs to assess material, tooling access, ends and tolerances.

Number of axes and tooling

Axis count indicates the number of controlled movements in a particular design, but a higher count alone does not prove suitability. Ask the supplier to map the required spring features to the machine's actual movements and tooling. Look for interference during forming and release.

Jinchun's CNC versatile spring coiling machine is a candidate for a drawing-based equipment review. Request a confirmed configuration before committing to a wire range or spring family.

Feeding accuracy and pitch control

Feed consistency influences how much wire reaches the tooling, while pitch control establishes the spacing between coils. Incoming wire variation, payoff behavior and tool condition can still affect the result. Inspect finished springs instead of treating a feed-accuracy claim as the tolerance of every spring feature.

Left hand and right hand coiling

State the required winding direction on the drawing and verify it against the assembly. Ask whether a direction change needs a program change, tool repositioning or different tooling. Do not assume that a controller setting alone provides both configurations.

If both winding directions are needed, include them in the acceptance plan. Check end geometry and release behavior in each direction, because a successful coil body does not establish that the complete part can be produced.

Changeover and program storage

A saved program should be accompanied by tooling identification, setup dimensions and material information. Record the approved drawing revision and inspection results with the setup. This makes it possible to reproduce the process after a tool change or a different operator takes over.

Ask the supplier to change to a second spring and then restore the first. Measure the time to the first accepted part and record startup scrap. Program capacity is less useful than a demonstrated, repeatable changeover on the actual product mix.

Sample trial and measurement

Use representative production wire and agreed measurement methods. Test springs from startup and stable running, then repeat checks after a controlled restart. Where stress relief, grinding or another operation forms part of the production route, inspect the final spring after that operation as well.

Jinchun's first-article trial checklist for wire forming provides a useful approach to recording material, setup and sample results. It is written for 3D wire bending; adapt that documentation approach and add spring-specific force, torque and end-geometry tests.

Information required for a quotation

Provide drawings for the representative part family, wire specifications, coil supply details, batch sizes, output requirements and finished-spring tests. List the processes expected within the quoted scope, including any inspection or downstream treatment equipment.

Ask Jinchun to assess the spring drawings and identify the required tooling, test method and exclusions in writing. A useful proposal shows how each representative spring will be made and accepted, including the difficult part rather than only the easiest sample.

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