Some models share similar carbon types (24-ton, 30-ton, 36-ton, etc.), but while two models may have the same carbon type(s) it does not mean they share the same blank. The rod taper and in some cases the percentages of the carbon blend itself will lead to considerable differences in flex profile.
What does 24/30/36/40T mean?
Tonnage (T) is the world standard for rating graphite. Ultimately, tonnage corresponds to the stiffness of the graphite, with a higher tonnage rating making for a stiffer graphite. Modulus is a term often used in the U.S. market: the higher the tonnage rating, the higher the modulus (both are functionally a density description). A higher tonnage/modulus graphite means that less material is required and corresponds with a higher sensitivity, as vibrations are transmitted more effectively through the material. However, an increase in the tonnage rating also results in an increase in rod brittleness, which must be countered with specialized resins and construction techniques.
What are rod blends?
On our website, you will see some rods listed as a blend of several tonnages (such as 24/30T). The purpose of such a blend is to allow for a lighter, more sensitive rod, while maintaining the strong backbone provided by a lower tonnage. In some cases, this is a full, layered blend from butt to tip; in others, sections of carbon are carefully laid out along the length of the blank before rolling. This form of patchwork can provide additional sensitivity, or add the needed backbone or reinforcement to specialize a blank for a certain action.