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Wilson

NXT Duramax 15 (1.40)

Nylon Gauge 15 1.40 mm In production

Lab measurements for Wilson NXT Duramax 15 (1.40), 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

162lb/in

lower = softer, kinder on the arm

Tension loss

18%

lower = stays where you strung it

Energy return

92%

higher = livelier, more free power

Spin potential

4.5

higher = more spin off the string bed

Ball bite

0.398COF

higher = grabs the ball harder

Snapback

0.089COF

lower = strings slide and snap back

How it ranks against all 789 strings

Stiffness 162 lb/in · 28th pct

Stiffer than 28% of strings tested.

Tension loss 18 % · 10th pct

Sheds more tension than 10% of strings tested — outstanding tension maintenance.

Energy return 92 % · 72nd pct

Livelier than 72% of strings tested.

Spin potential 4.5 · 43rd pct

More spin potential than 43% of strings tested.

Ball bite 0.398 COF · 22nd pct

Grips the ball harder than 22% of strings tested.

Snapback 0.089 COF · 44th pct

More string-on-string friction than 44% of strings tested.

Strings that play like this

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

Prince Perfection 16 (1.30) 96% match Klip Scorcher 17 (1.27) 95% match Toalson Leoina 77 (1.30) 95% match Gosen AK Pro 17 94% match Gamma TNT2 Tour 17 (1.27) 94% match Babolat SG SpiralTek 16 93% match

More from Wilson

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 NXT Duramax 15 (1.40) against 789 strings Find the right string for me