Search - Content
Search - People/Events
Search - Forums
Search - Finance/Stocks
Search - Newsfeeds


Welcome, Guest

Armor weight in power cables
(1 viewing) (1) Guest
If you have a question regarding coaxial, telephone, and building wire, power cable, insulation, extrusion, bunching, stranding, braiding, etc. post it here.
  • Page:
  • 1

TOPIC: Armor weight in power cables

Armor weight in power cables 1 year, 7 months ago #1722

Hello everybody...

We work with a power cable manufacturing firm. We use 4mm x 0.8mm Steel strip / steel wire of diameter 1.40mm for armoring the assembled cable cores. Can anybody explain how to calculate the exact weight of steel, used as armor in a particular cable? It varies as and when lay length varies rite? We used the following formulas, but we are unable to standardize the X factor,do exactly.

Strip: (4*0.8*n*density*X) grams / m
Wire: (0.7857*1.40*1.40*n*density*X) grams / m

where n is number of wires / strips. Any idea on the lay length connection to the value of X shall be greatly appreciated.


Re: Armor weight in power cables 1 year, 7 months ago #1723

Hello alwin18,

When dealing with a multitude of very small metallic wires or strips helically wrapped over a relatively large diameter cable with a smooth and reasonably round outer surface and with "100%" coverage, the gaps between the individual wires or strips may indeed become a relevant factor. This might be what is throwing off your calculations. One way to do this would be to determine a constant experimentally. Another way would be to contact a technical expert in braiding manufacturing and see if they have a set of modified equations or algorithm for multi wire spiral winding AKA as helix winding that you could use. The first name that comes to mind is:

Mr. Frank Knobloch
Product Manager Braiding & Winding
Maschinenfabrik Niehoff GmbH & Co KG
F├╝rther Strasse 30
91126 Schwabach
Phone: +49 9122 977-240
E-Mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
Web site:

If Frank doesn't have the answer, perhaps he can refer to you to someone who has this information.

Please let us know what you found out. Thank you.

Peter J. Stewart-Hay
Stewart-Hay Associates
519 641- 3212

Re: Armor weight in power cables 1 year, 7 months ago #1724

To calculate the increase in length due to lay, all you have to do is use Pythagora's theorem i.e. square of actual wire length=square of linear cable length + square of mean diameter of armouring. Mean diameter of armouring= diameter over innersheath+one strip/wire thickness/diameter.

naren kotecha

Re: Armor weight in power cables 1 year, 7 months ago #1725

By length-in both above cases-I meant length of one lay of armour which should give ratio of actual wire length versus cable length

naren kotecha

Re: Armor weight in power cables 1 year, 6 months ago #1757

Hi Peter

thanks for the suggestions...we normally go by the individual wire calculation and not by considering the armour like a metal sheet...
  • Page:
  • 1
Time to create page: 0.45 seconds