String comparison
Tornado vs V-Square
Signum Pro Tornado against Volkl V-Square: ratings, specs and which one fits your junior.
The short answer
Both are polyester strings. V-Square leads on spin, durability and tension hold. For a junior with arm concerns, V-Square is the safer choice. V-Square costs less per set.
Ratings
Power
Spin
Control
Comfort
Durability
Tension hold
Ratings are on a 1–10 scale. The higher score is in bold when they differ.
Pick Tornado if…
- Best for: spin-oriented advanced juniors
- Best for: players who like a textured, grippy string
Pick V-Square if…
- You want more spin (10 vs 9 out of 10)
- You want more durability (7 vs 6 out of 10)
- You want more tension hold (7 vs 5 out of 10)
- Arm comfort comes first (arm friendliness 3/5 vs 2/5)
- Your player is younger (recommended from age 13 vs 14)
- You want to spend less (from $12 vs $15 a set)
- Best for: maximum spin seekers
- Best for: players with western/semi-western grips
- Best for: those who prioritize spin over everything else
Specs side by side
| Spec | Tornado | V-Square |
|---|---|---|
| Type | Polyester | Polyester |
| Construction | Heptagonal (7-sided) co-polyester with an axial twist, extruded, cooled, then reheated and twisted | Square-shaped co-polyester monofilament with 4 sharp edges |
| Gauges | 16, 17, 18 | 16, 17, 18, 19 |
| Stiffness | Medium high | Medium |
| Set price | $15–15 | $12–15 |
| Reel price | $160–160 | $140–160 |
| Arm friendliness | 2/5 · Low | 3/5 · Moderate |
| Cost to maintain | 3/5 | 4/5 |
| Recommended from | Age 14 | Age 13 |
| Levels | Advanced, Elite | Intermediate, Advanced, Elite |
| Play styles | Baseliner, Big hitter | Baseliner, Big hitter |
| Junior tension | 44-50 lbs for juniors. Signum suggests about 10% lower than usual. | 48-52 lbs for juniors. Square shape maximizes bite so can string lower. |
Tornado in short
Signum Pro Tornado is a seven-sided co-poly with an axial twist, made by extruding a straight string, cooling it, then reheating and twisting it. Signum says the rough surface gives maximum bite on the ball and recommends stringing about 10% lower. Tennis Warehouse customers describe it as stiff and less arm-friendly. The TWU lab measured moderate-to-high stiffness and a fairly high tension loss, so expect it to need regular restrings.
V-Square in short
Volkl V-Square holds the top score for bite (string-on-ball friction) in the Tennis Warehouse University String Lab. The 4-sided square profile with razor-sharp edges creates vicious snapback and maximum spin potential. Made with an exclusive material for improved comfort with minimal tension loss, V-Square sits between Cyclone and Cyclone Tour in terms of overall feel while offering perhaps the best spin potential in the Volkl lineup.
Tornado vs V-Square: quick answers
Which has more spin, Tornado or V-Square?
Volkl V-Square, with a spin rating of 10/10 against 9/10.
Which is more arm-friendly for a junior?
Volkl V-Square scores 3/5 for arm friendliness, against 2/5 for Tornado. It is recommended from age 13.
Which lasts longer?
Volkl V-Square rates 7/10 for durability against 6/10.
Which is cheaper?
Tornado costs about $15–15 a set and V-Square about $12–15, at typical retail.
The short answer and the "pick if" lists are generated from our ratings and junior data only. Data verified 2026-10 (Tornado) and 2025-01 (V-Square).