Guide to Crimping Fine Stranded Conductor 

CABAC recommends that where possible the normal lug and die format is used, and there is NO necessity to use a different lug or die if the conductor strands will fit into the lug. CABAC laboratory has tested the resultant crimp and test certificates can be issued on request.

The most important point to remember is that with fine strands more force than normal is required to complete the crimp. Fine stranded cables have differing numbers of strands from different manufacturers, and the lay of those strands also differs from a “rope lay” to “flat lay” making it difficult to predict whether a conductor will fit in a lug. Generally, use bell mouth lugs when crimping fine strand cable as this will assist when inserting the conductor into the barrel.

Small cables approximately 16 sq. mm and less: in this case simply use a normal lug since the stranded conductor fits, and crimp normally. 

Mid range cables approximately 25 sq. mm to the 185 to 240 sq. mm range: in this case use a standard bell mouth lug for that cable size. At the cut end, the conductors splay out more and the conductors get relatively larger in diameter. Defining the point at which a conductor will not fit into a lug can only be done by actual trial, but in general it is in the 185 to 240 sq. mm area. Crimp the normal way using normal tooling, however using a 13 tonne HT131-C tool to 120 sq. mm and an ECW-H3D (23 tonne) tool for 150 sq. mm and above. 

Large fine stranded cables from approximately 185 to 240 sq. mm and above: where the conductor will not fit into the lug, we recommend using a lug one size up. To crimp these there are two acceptable methods:

First crimp the lug with its normal die, and then re-crimp the lug with half a lug size die and half a cable size die. Use an ECW-H3D tool and make sure that the dies close. A 12/13 tonne tool will not produce enough force to achieve a good crimp. To achieve the minimum resistance, the full length of the barrel should be crimped, and match and line up the dies on previous crimps for the best results.To explain in easier terms, say I have a 240 sq. mm conductor that will not fit into a 240 sq. mm bell mouth lug, I then use a 300 sq. mm lug (CAL300). I then crimp the entire lug with a 300 sq. mmdie, and then replace one half of dies with a 240 sq. mm die and re-crimp the lug.

CABAC can calculate the required across the flat measurement (AF) and recommend an alternative die.If you have any reservations or require assistance, please contact your CABAC sales representative or CABAC laboratory. CABAC can confirm or suggest an alternative lug or die to suit your specific conductor.