What Is Tinned Copper Wire Braid?

A tinned copper wire braid is a form of electrical cable made by braiding fine tinned copper wires. Copper braided wire is extremely flexible, strong, and resistant to vibration. It has excellent shielding properties. Tinned copper wire has better oxidation and corrosion resistance properties than pure copper. Many types comply with MIL-Spec AA59569.

Types of Tinned Copper Wire Braid

The two main types of wire braid are tubular and flat.

Tubular Braid

All braid starts as a tubular braid manufactured on complex braiding machines. The machine feeds strands of tinned copper wire onto multiple carriers that rotate around a mandrel, weaving the wires into a tightly wound circular braid.

Flat Braid

To make a flat braid, manufacturers run tubular braid through powerful pressure rollers. This flattens the tube to create a broad, flexible braid with good surface area and exceptional electrical and mechanical properties.

Insulated Braid

An uninsulated braid is used for grounding, screening, and making electrical connections in the air. It's also possible to insulate tubular and flat braid to form an insulated cable that has excellent high-frequency properties.

Braid Construction Identification

The industry has a standard nomenclature for identifying braided wires with the format XX-YY-ZZ:

  • The first digits, XX, refer to the number of carriers or strands
  • The next two digits, YY, refer to the number of wires per strand
  • The last digits, ZZ, refer to the diameter of the individual wires

In the United States, it's usual to measure wire sizes using the American wire gauge, whereas European companies measure wire diameter in millimeters. A 48-32-30 braid has 48 strands, each made up of 32 wires of 30 AWG wire.

Braid Size

The overall size of the braid is the equivalent AWG size or equivalent circular mils. In the example above, the equivalent size is 3/0 AWG.

Current Rating

For simplicity, AWC provides the current rating of the wire at normal temperatures, measured in amps.

Measuring Braid

You measure the size of tubular braid by its nominal internal diameter. For flat braid, you use the nominal width and thickness. Braids are flexible, so these dimensions vary slightly, especially if the braid is under tension.

AA59569 Military Specification Braids

AA59569 is the Commercial Item Description (CID) used to define certain copper wire braids. It's used by the military and Federal government departments. Braids manufactured in terms of this specification use a part identification number (PIN) that’s made up as follows:

  • The CID specification number, AA59569
  • The letter R for tubular braid or F for a flat braid
  • The size in AWG of the individual wire strands
  • The letter T indicates tin-coated copper or S for silver-plated copper
  • The nominal inside diameter in mils

For example, the following PIN, AA59569R36T0062 refers to a 19 AWG tubular braid made from 36 AWG tin-plated copper wire strands with a nominal internal diameter of 62 mils (0.0062 inches).

Applications for Copper Wire Braid

The compact dimensions of tubular braids make them ideal for fitting into machinery and electrical panels. Another common application is sleeving for screening electrical cables from electromagnetic interference. You can use flat braids as flexible connections, earthing cables, electrical switchgear, and aerospace applications. Their ability to withstand vibration makes them a good choice where there's a high risk of metal fatigue, such as in marine and land vehicles. Their ability to flex and stretch makes them a good solution for moving electrical contacts in switchgear and accommodating expansion and contraction in high-temperature furnaces.

Contact us for further information on selecting flat or tubular wire braids or for custom cables such as stainless steel or silver-plated copper wire braid.