In this series, we will look at the various characteristics of tennis string without the tennis racquet!

Racquet Quest evaluates every string we use plus strings submitted from other sources. These evaluations are “No Prep” and “Prep”, which simply means the Prep string has been pre-stretched in the entire length. It has not been through a tennis racquet…yet!

The following images represent a string that has not been “prepped.”  After these plots are fully understood we will do the same string in the”prepped” format to see if there is a difference.

Ultimate Tensile Strength

What we notice immediately is the string is very “soft” as seen in the deflection of 47.8 mm to reach 50 pounds.  Also, the elasticity, the ability to recover to the original length, is fairly low.

The area under the 50-pound and 47.8 mark is the stress/strain curve that shows how the string behaves in three (3) cycles.  The load and number of cycles can be changed.

The long run (linearity) from the 50-pound mark to failure is quite good and suggests consistency.

The UTS, the ultimate tensile strength, of 127.1 pounds is good for this thin string.

The following plot shows the knot strength of this string.

Knot Strength

This plot is overlayed on the previous image so a quick comparison can be made.  It is common for knot strength to be lower than un-knotted string.  Knot strength is primarily important to the person tying the knot.  Knots rarely fail after they are successfully tied.  Pulling a knot too tight or jerking can break a knot.

This plot says to us that this string needs to be handled carefully when it comes to knots!  We would expect a knot strength of at least 80 pounds for typical monofilament strings, however, if this string exhibits extraordinary play characteristics anyone can learn to tie the knots!

Based on this information we would suggest this string for a player looking for extraordinary comfort, power, and relatively short life!