What data is provided in the Thomastik-Infeld string catalog and what does it mean?

Our string catalog is split into four instrument categories: violin, viola, cello and bass. You will find our product lines and the associated strings and string sets in alphabetical order in these categories. At the very top, available sizes (full size: 4/4; fractional sizes: 3/4, 1/2, 1/4, 1/8, 1/16) and tensions (light, medium, heavy) of each product line is stated. There is a wealth of further information which we have listed in brief for you:


For which instrument the string should generally be used.

Catalog number 

All catalog numbers refer to medium tension. For light tension, add „W“ (German: weich) to the catalog number (e.g. 135W or S42W). For heavy tension, add „ST“ (German: stark) to the catalog number (e.g. S36ST or VI100ST).


The keynote is the lowest note of a string.

Vibrating string length

The vibrating string length is the distance from the inner edge of the bridge to the inner edge of the nut. To choose the right strings and the correspondingly correct string tensions, you need to know the vibrating string length of your instrument. The vibrating string length is stated in both centimeters and inches in the catalog.

Usable from/to 

There are some strings that can also be used for a varying vibrating string length. The range is stated separately. Please note that the string tension changes in this case: if the length increases, the string tension is squared! 

String tension   

The string tension is the force that must pull on a string in order to generate the desired tone for a specified vibrating string length. The string tension is stated in kilograms and pounds. It always relates to the vibrating string length stated in the catalog.  Conversion: 1 kg = 2.20462 lb

Core material and outer winding  

The Thomastik-Infeld catalog contains information about the core material used and normally the material of the outermost layer, too. A string can consist of up to eight winding layers and high-tech filler materials. We also use simplified terms for the materials in the catalog to make the information more understandable. Thomastik-Infeld uses six different string cores:

  • Carbon steel        
  • Stainless steel
  • Rope Core        
  • Spiral Core
  • Synthetic core     
  • Composite core

Despite the strictest compliance with the most stringent production and quality criteria, traces of materials other than those stated may be found in the string. For detailed information about the materials used, please contact [email protected].   



Tailpiece end 

Thomastik-Infeld offers four different string ends for tailpieces:


The ball ends can be made from the following materials:


Color marking of tailpiece end und peg end

To identify the products, our strings are marked with Thomastik-Infeld’s own silks at the tailpiece and peg end. The following colors are used for this:



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