Classical string packages use tension classes rather than steel-string gauge conventions. The same normal-tension label can differ between manufacturers because materials, diameters, and construction methods differ.
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Key takeaways
- Classical sets are compared by tension family and construction, not by steel-string gauge labels.
- Nylon, fluorocarbon, composite trebles, and multifilament wound basses require material-specific data.
- Normal and hard are product-family labels; compare the manufacturer’s six per-string tension values when available.
- Never substitute steel strings on a guitar built only for classical or nylon strings.
How to use this: Use these recommendations to compare options, then check the final set against the string maker's specifications and confirm that it suits your instrument.
Low, normal, and high tension
Low-tension sets generally fret and vibrato more easily, with wider string excursion. Normal tension is the broad reference point. High-tension sets resist the right hand more strongly and can support firm attack, but they also increase total load and may expose setup issues.
Mixed-tension sets combine classes—for example, normal trebles with high-tension basses—to change balance without moving the whole instrument in one direction.
| Class | Typical response | Potential tradeoff |
|---|---|---|
| Low | Soft left-hand feel and broad vibration | May need more action clearance |
| Normal | Balanced general-purpose response | Brand-to-brand values still vary |
| High | Firm attack and reduced excursion | Higher load and greater fretting effort |
| Mixed | Targeted treble/bass balance | Requires careful product comparison |
Nylon, fluorocarbon, composite, and bass strings
Clear or rectified nylon trebles differ in surface and consistency. Fluorocarbon trebles are denser, so they can reach pitch at a smaller diameter and often produce a more immediate response. Composite formulations occupy a range between familiar nylon feel and denser modern materials.
Classical basses typically use a multifilament core with metal winding. Their printed diameter does not reveal the core and wrap mass, so manufacturer tension tables are the most reliable source.
Worked example: one published hard-tension set
D’Addario publishes individual values for its EJ46TT Dynacore hard-tension set. The figures below show why a package label is not a target for six identical tensions.
The values are product-specific, measured in pounds-force, and should not be transferred to another material or brand.
| Pitch | Published tension | Role in the set |
|---|---|---|
| E4 | 17.0 lbf | First-string treble |
| B3 | 12.6 lbf | Second-string treble |
| G3 | 12.4 lbf | Third-string treble |
| D3 | 15.3 lbf | Fourth-string wound bass |
| A2 | 17.0 lbf | Fifth-string wound bass |
| E2 | 16.4 lbf | Sixth-string wound bass |
Source: D’Addario EJ46TT product tension chart. Values are reproduced as technical reference data for this named set.
Classical, flamenco, and crossover guitars
A lightly built classical guitar may respond best with normal or low tension, while a flamenco setup may pair firm strings with low action and a controlled right hand. Crossover instruments vary widely. Follow the maker’s stated range and judge the complete setup rather than a single label.
Why the steel-string calculator is not used here
The main Guitar String Tension Calculator model estimates plain steel and steel-core wound strings. Nylon, fluorocarbon, multifilament cores, and classical bass constructions need different density and unit-weight data, so the steel model is not used for those strings.
For exact comparisons, use the tension figures published for the specific classical set. Compare all six strings and the total, then evaluate action, relief, and bridge condition after installation.
Reference material
Technical references
Use these manufacturer references when you need product-specific tension or setup information. They were last reviewed on ; the gauge suggestions on this page remain starting points because strings and instruments vary.
Before you change strings
Save your current setup, change one variable at a time, and recheck tuning, neck relief, action, and intonation after the new strings settle. If a result looks inconsistent with your instrument or a manufacturer's data, send the setup details through the contact page.