Blue Die Springs, 65Mn Rectangular Wire — TL/SWL Light Load — Pack of 2
Standard-part returns: request authorization within 14 days after delivery; item must be unused, uninstalled, undamaged and in original packaging. Review the full return policy.
Need a non-standard size? Request a Quote →Blue rectangular-wire die springs in 65Mn spring steel, electrophoretic-coated, for mold and die maintenance or replacement. Sold in packs of 2. Sizes are given as outside diameter × free length in millimetres.
Load class — read this before ordering
These springs follow the JIS-style colour system, where blue is TL — light load. It is the general-purpose middle of the three classes we stock.
This is not the same as ISO 10243, where blue means medium load. If your drawing or your existing tool calls out an ISO blue spring, these are softer than what you are expecting. When in doubt, work from the load values below rather than from the colour.
Maximum compression depends on the life you need
Compression limits are quoted against a cycle count, and confusing the two figures is the commonest reason die springs fail early. For blue TL:
| Cycle life | Max compression (% of free length) |
|---|---|
| 300,000 cycles | 40% |
| 500,000 cycles | 36% |
| 1,000,000 cycles | 32% |
| Solid (reference only) | 43% |
Design a long-run production tool against the 32% figure and treat 40% as a short-life limit rather than as headroom. The solid figure is a reference for clearance calculations, not an operating condition. A spring that comes back out shorter than its original free length has already been over-compressed and will not recover.
Maximum compression load by outside diameter
Blue TL, at 40% compression — the 300,000-cycle basis. These values depend on outside diameter alone: an 8 × 60 spring has the same limit load as an 8 × 20. Free length changes the available stroke, not the peak force. For the one-million-cycle basis (32%), multiply by 0.8.
| OD (mm) | ID (mm) | Max load (kgf) | Max load (N) | Max load (lbf) |
|---|---|---|---|---|
| 6 | 3 | 8 | 78 | 17.6 |
| 8 | 4 | 10 | 98.1 | 22.0 |
| 10 | 5 | 14.5 | 142.2 | 32.0 |
| 12 | 6 | 21 | 206 | 46.3 |
| 14 | 7 | 28 | 275 | 61.7 |
| 16 | 8 | 35 | 343 | 77.2 |
| 18 | 9 | 43 | 422 | 94.8 |
| 20 | 10 | 54 | 530 | 119.0 |
| 22 | 11 | 67 | 657 | 147.7 |
| 25 | 12.5 | 84 | 824 | 185.2 |
| 27 | 13.5 | 100 | 981 | 220.5 |
These are limit values. For a design you intend to run production on, keep normal working compression well below the maximum; running at the limit shortens fatigue life sharply.
Same size, different load class
All three colours share outside diameters and free lengths, so they are dimensionally interchangeable at the same OD. What changes is the force and the usable stroke. At Ø25, for comparison: yellow gives 50 kgf at 50% compression, blue 84 kgf at 40%, red 125 kgf at 32%. More force, less travel, in that order.
- Yellow — TF, extra light. Less force than blue, but tolerates more compression for the same cycle life. The right answer when you need travel in a shallow pocket. Note its inside diameter is larger at Ø20 and Ø25 (11 and 13.5 mm against blue's 10 and 12.5) because the wire is thinner.
- Blue — TL, light (this page). Roughly 1.4 to 1.7 times the yellow load at the same outside diameter.
- Red — TM, medium. About 1.5 times blue again, with less stroke. Ø20 and above only.
Specifications
| Material | 65Mn spring steel |
| Wire section | Rectangular |
| Surface | Electrophoretic coating |
| Service temperature | −30 °C to +150 °C |
| Colour / code | Blue, TL |
| Load class | Light (JIS-style system) |
| Sizes available | Ø8, Ø10, Ø12, Ø16, Ø20, Ø25 × 20–100 mm free length |
| Pack quantity | 2 pieces |
| Origin | Danyang, Jiangsu, China |
Choosing a size
Check outside diameter against your bore, inside diameter against any pin the spring sits over, free length against your installed height, and confirm the working compression your application needs falls inside the limit for the cycle life you are designing to. If you are replacing an existing spring, matching outside diameter, free length and colour is usually enough.
Need something else?
Ø6, Ø14, Ø18, Ø22 and Ø27, free lengths to 300 mm, and heavier classes are available. Request a quote with your size and required load, and we will come back within one business day.
Shipping
International freight is calculated on packed chargeable weight. See Shipping & Delivery for destinations and transit times.
Packaging images are illustrative. Actual protective materials and carton format vary with size, quantity and shipping route.
- Material grade
- 65Mn spring steel
- Hardness / load grade
- TL / SWL light-load class (JIS-style colour system)
- Surface treatment
- Blue electrophoretic coating
- Key tolerance
- Confirm controlling dimensions before ordering
- Metric specification
- Outside diameter × free length (mm)
- Package quantity
- 2 pieces per pack
- Single-piece weight
- To be confirmed
- Package weight
- To be confirmed
- Country of origin
- Danyang, Jiangsu, China
- Processing time
- Varies by specification; confirm before ordering when timing is critical
- International freight
- Quoted from packed chargeable weight; carrier transit time is estimated separately
- Typical application
- Mold and die return, preload and compression applications
- How to select
- Match load class, outside diameter, free length and working compression.
- Check before ordering
- Outside diameter, inside clearance, free length, installed height and working stroke
- Non-standard dimensions
- Submit an RFQ with a drawing, photo or measured dimensions