Intro
The running length is often mentioned in connection with sewing and embroidery thread strength. Officially, the running length is not considered a linear density indicator such as Tex or Nm; however, in practice it is frequently used as one.
The running length indicates how many metres of thread weigh 1 kg. Expressed as m/kg, it is closely related to the fixed-length system Nm (m/g). For this reason, the running length is mainly used in Europe, where linear density is expressed in Nm.
As with all fixed-length systems, the following also applies to running length: the higher the ticket number or effective count of a thread, the finer the thread and the greater the running length per unit of weight.
In order to calculate the approximate running length of a thread, the ticket number is divided by 3 and the result is multiplied by 1,000.
Example:
Saba 120 has an approximate running length of 40,000 m/kg.
(Calculation: 120 ÷ 3 = 40; 40 × 1,000 = 40,000).
The effective count should be used to calculate the exact running length of an article. The following formula applies: effective count divided by the number of plies, multiplied by 1,000.
Example:
Saba 120 has an effective count of 72/2 Nm, which corresponds to a running length of 36,000 m/kg
(Calculation: 72 ÷ 2 = 36, 36 × 1,000 = 36,000)
FAQ
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Running length describes how many meters of thread are contained per kilogram. It is expressed as m/kg.
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No, it is not an official numbering system. However, it is often used in practice.
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Finer threads have a higher running length. Coarser threads have a lower running length.
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It can be estimated using the ticket number or exact count. Formulas are based on length-based systems.
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It helps estimate material consumption. This is important for cost calculations.
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It is mainly used in regions where Nm is common. It is especially relevant in Europe.
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No, it should be used as a complementary value. Official specifications remain Tex or Nm.
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It allows better estimation of thread usage and logistics. This improves efficiency.