Pen spring
Micro compression springs for retractable pens and click mechanisms. Design the exact wire diameter and length and quote instantly.
Recommended type and material
Pens need fine-wire stainless 302 springs, which resist handling corrosion and hold a stable click force over thousands of cycles. The ground end seats flat in the pen body.
Reference specification
| Type | Compression |
|---|---|
| Material | Stainless 302 |
| Wire diameter | 0.35 mm |
| Outer diameter | 3 mm |
| Length | 18 mm |
| Spring rate | 0.87 N/mm |
| Max safe load | 4 N |
| Solid height | 3.5 mm |
| Spring index | 7.6 |
Values calculated for the reference example; adjust everything in the designer.
Things to consider
- Fine wire (0.3–0.5 mm) with tight force tolerance.
- Stainless 302 avoids corrosion from hand contact.
- High production cadence with very low unit cost.
Design your spring for this application
Open the example in the designer, adjust the dimensions and get an instant quote.
Design & quoteFrequently asked questions
What is the typical wire diameter?
Between 0.3 and 0.5 mm depending on the desired click force.
Which material is recommended?
Stainless 302, for corrosion resistance and stable force over cycles.