General definitions

  
 

Wire or Steel filament

A steel fiber used as an individual element in a steel strand or cord.

Strand (of steel)

A group of steel filaments twisted together to form a unit product to be processed further. A strand may be considered as a cord if it is the end product for tire reinforcement or it may be an element in a more complex structure.

Cord (of steel)or Steel Cord

A formed structure composed of two or more steel filaments when used as an end product or a combination of filaments and strands.

Core (in steel tyre cord)

A filament, filaments or strand that serves as an extended axis about which other elements can be wound.

Wrap

A filament wound around a steel cord.

 

Lenght of lay

The axial distance required to make a 360 degree revolution of any element in a strand or in a cord, expressed in millimetres.

Direction of lay

The helical disposition of the components of a strand or cord. The strand or cord has an "S" or lefthand lay if, when held vertically, the spiral around the central axis of the strand or cord conform in direction of slope to the central portion of the letter "S"; and "Z" or rightand lay the spirals conform in direction of slope to the central portion of the letter "Z".

 

Direction of lay

The helical disposition of the components of a strand or cord are designated according to the undermentioned generale rules:

• strand used as an end product: S 
• ordinary or regular lay cord:    
• Lang's lay cord (LL): strand and cord S strand S
• Lang's lay cord (LL): strand and cord S cord Z
• spiral wrap: opposite to the direction of the cord lay