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Signum Pro

Tornado 18 (1.17)

Polyester Gauge 18 1.40 mm In production

Lab measurements for Signum Pro Tornado 18 (1.17), ranked against all 789 strings in the database. Every figure below is a testing-machine result at a fixed reference tension, not a playtest opinion.

Measured values

Stiffness

167lb/in

lower = softer, kinder on the arm

Tension loss

39%

lower = stays where you strung it

Energy return

86%

higher = livelier, more free power

Spin potential

5.9

higher = more spin off the string bed

Ball bite

0.546COF

higher = grabs the ball harder

Snapback

0.092COF

lower = strings slide and snap back

How it ranks against all 789 strings

Stiffness 167 lb/in · 36th pct

Stiffer than 36% of strings tested.

Tension loss 39 % · 66th pct

Sheds more tension than 66% of strings tested.

Energy return 86 % · 29th pct

Livelier than 29% of strings tested.

Spin potential 5.9 · 78th pct

More spin potential than 78% of strings tested.

Ball bite 0.546 COF · 90th pct

Grips the ball harder than 90% of strings tested.

Snapback 0.092 COF · 50th pct

More string-on-string friction than 50% of strings tested.

Strings that play like this

Closest matches across stiffness, tension loss, energy return and spin potential.

Tourna Big Hitter Black 7 17 94% match Gosen Poly Professional 17 (1.24) 94% match LaserFibre Vorso 17 (1.23) 93% match Signum Pro Hyperion 18 (1.18) 92% match Head Lynx 18 (1.20) 92% match Solinco Barb Wire 16L (1.25) 90% match

More from Signum Pro

What these numbers mean

Stiffness · lb/in

How much the string bed resists deflection. Higher plays firmer and more controlled; lower plays softer and easier on the arm.

Tension loss · %

Share of the reference tension the string sheds under a fixed test protocol. Lower means the bed stays where you strung it for longer.

Energy return · %

Share of impact energy handed back to the ball. Higher plays livelier and more powerful.

Spin potential

Ball friction divided by string-on-string friction. Higher means better bite with a cleaner snapback, so more spin.

Ball bite · COF

String-on-ball friction. Higher grabs the ball harder through the brush.

Snapback · COF

String-on-string friction. Lower lets the mains slide and snap back into place after impact.

Compare Tornado 18 (1.17) against 789 strings Find the right string for me