Puerto Rican cuatro string tension
A Puerto Rican cuatro carries ten steel strings in five courses, tuned B E A D G. In the D'Addario EJ96 set the top three courses are unison pairs of .011, .014 and .024, and the two bass courses pair a wound string with an octave string: .032 with .014 on E, .042 with .024 on B. D'Addario's figures add up to 210.8 lb (95.6 kg); the calculator gives about 213 lb (96.7 kg) on a 515 mm scale.
Tension of the D'Addario EJ96 set, string by string
Standard B E A D G tuning from the 1st course (G4) on a 515 mm scale, calculated with the unit weights from D'Addario's tension chart; D'Addario's own figures run about 13 % higher on the plain strings and up to 16 % lower on the wound ones.
| String | Note | Gauge | kg | lb |
|---|---|---|---|---|
| 1 | G4 | .011 | 7.9 | 17.5 |
| 2 | G4 | .011 | 7.9 | 17.5 |
| 3 | D4 | .014 | 7.2 | 15.9 |
| 4 | D4 | .014 | 7.2 | 15.9 |
| 5 | A3 | .024w | 10.9 | 24.1 |
| 6 | A3 | .024w | 10.9 | 24.1 |
| 7 | E4 | .014 | 9.1 | 20.1 |
| 8 | E3 | .032w | 11.0 | 24.3 |
| 9 | B3 | .024w | 13.8 | 30.3 |
| 10 | B2 | .042w | 10.8 | 23.8 |
How to use it
- The page opens with the Puerto Rican cuatro, the EJ96 set and standard B E A D G tuning.
- Switch to the La Bella 700C set to compare: same .011 to .042 range, different middle gauges.
- Edit the scale or a gauge and watch the total and the per-string difference.
Help and explanations
The calculator starts from that set on a 515 mm scale. Change any gauge, switch to the La Bella 700C or edit the scale, and every string is recalculated in kg, lb or N.
The EJ96 set, course by course
D'Addario lists 20.2 lb on each .011 (G4), 18.4 lb on each .014 (D4) and 20.7 lb on each .024 wound (A3). On the E course, the .032 wound on E3 carries 21.6 lb and its .014 octave on E4 23.1 lb. On the B course, the .042 on B2 carries 21.4 lb and the .024 on B3 26.1 lb, the highest in the set.
The La Bella 700C uses the same outer gauges, .011 and .042, but a .015 instead of the .014 and .022 instead of the .024, and comes with ball ends.
Why the calculator and the package differ
The calculator uses T = UW × (2 × L × F)² ÷ 386.4 with unit weights from D'Addario's String Tension Specifications. At 515 mm it gives about 13 % less than the package on the plain strings and up to 16 % more on the wound ones: 17.5 lb against 20.2 on the .011, 30.3 against 26.1 on the B3 .024.
No single scale explains both: the plain strings match at about 553 mm, the wound strings at about 481 mm. D'Addario doesn't say whether the B3 .024 is plain or wound, nor what scale it used, and its wound strings are silver-plated copper, which the chart doesn't list: the calculator uses phosphor bronze, the closest alloy. The table below is the calculator's result at 515 mm; the package figures are the ones quoted above.
Tips
- If the B course octave string breaks often, it's working hardest: 26.1 lb on a .024 according to D'Addario, 30.3 lb in the calculator.
- To fit the strings, see how to restring a Puerto Rican cuatro.
- Tune the octave courses string by string with the Puerto Rican cuatro tuner.
Frequently asked questions
What gauge strings does a Puerto Rican cuatro use?
The D'Addario EJ96 uses .011/.011 on G, .014/.014 on D, .024/.024 on A, .032/.014 on E and .042/.024 on B. The La Bella 700C runs .011/.011, .015/.015, .022/.022, .032/.015 and .042/.022.
How many strings are on a Puerto Rican cuatro?
Ten, in five double courses. The B and E courses are octave pairs; the A, D and G courses are unison pairs.
How is a Puerto Rican cuatro tuned?
B E A D G from the lowest course: B2 + B3 (123.47 + 246.94 Hz), E3 + E4 (164.81 + 329.63 Hz), A3 (220.00 Hz), D4 (293.66 Hz) and G4 (392.00 Hz), at A 440 Hz.
What is the total tension of a cuatro set?
About 211 lb (96 kg) for the D'Addario EJ96 by the manufacturer's figures (213 lb in the calculator at 515 mm), more than a steel-string acoustic guitar with 12s (about 163 lb) on a much shorter scale.
Can I use Venezuelan cuatro strings?
No. The Venezuelan cuatro uses four nylon strings, while the Puerto Rican cuatro needs ten steel strings.