WHEN AND WHERE TO USE TINNING

Improving Wire’s Performance application of a wire coating, the most popular of which is tinning. How do you determine Electrical wiring serves one purpose — it whether or not to specify tinned wire for your conducts an electrical current from one point to application? Let’s take a closer look at when another. The wire’s ability to conduct electricity and where to use tinning. is affected by several factors, including the primary material of the wire, the operating temperature in which the wire will be used, and Choose Wire Type how much mechanical stress (twisting, stripping, Wire is chosen based on the properties soldering, etc.) the wire will be required to required for the application for which and the endure. environment in which it will be used. Common uncoated electrical wire types and some of their Wire performance can be improved with the properties are compared in the following table.

Properties of Uncoated Wire by Type WHEN AND WHERE TO USE TINNING

Why Coat Wire? purpose is to extend the and silver-coated wire has Similarly, wire coatings operating temperature exceptional solder properties. are chosen based on the range of affordable bare properties they impart to the wire, taking it to 450°C Unfortunately, these desirable base wire. or higher, depending on properties come at a price. coating thickness. It remains Silver coating can be Tinning provides an stable over time or with extremely expensive due to improvement in the operating small changes in operating the raw material costs and to temperature range, water temperature. Like tinning, the electroplating and drawing resistance, and mechanical nickel coating’s crimp process required to coat the strength of bare copper terminability is initially good, wire. wire. In addition, tinning is but contact resistance considered a soldering aid. deteriorates with time. Why Choose Tinning? Note that solderability and As discussed, tinning copper conductivity do degrade over Unfortunately, nickel coating wire imparts desirable time and/or rise in temperature has only 25% of copper’s characteristics to bare copper because of the migration of tin electrical conductivity and, in wire: and copper and tin oxidation. most cases, reduces a wire’s Crimp terminability is initially overall conductivity. In addition, • Soldering improvement quite good, but contact unlike other coatings, nickel resistance increases with time. coating requires active flux • Operating temperature range during solder. improvement Despite its shortcomings, tinning is an extremely Silver coating can greatly • Water and general corrosion affordable coating that, if improve the conductivity of resistance worked shortly after coating wire materials other than and allowed to age without copper and also improves • Good crimp terminability changes, is an extremely the operating temperature affordable solution for the range of bare wire. Its • Affordability improvements it imparts to conductivity remains stable bare wire. and its solderability is good Historically, tinning was used over the life of the wire. to protect bare wire from Nickel coating’s primary Contact resistance stays low, the corrosion caused by the WHEN AND WHERE TO USE TINNING

make-up of the wire itself — copper chemically such as water or pulp treatment operations. reacted with the freed sulfur ions released In fact, tinned conductors can extend wire from wiring insulation. Modern chemistry has life by ten times compared to bare wire. Its since created more stable wiring insulation, and affordability makes it extremely cost effective tinning is usually not required just to prevent in nearly any application for which corrosion corrosion from within. However, while not as resistance and higher operating temperatures commonly used, sulfur-bearing power-cable are required. insulations or chlorosulfonated polyethylene (CPSE) still require tinning to protect copper Choose Tinning Type wire from sulfur-caused (i.e., copper sulfide) corrosion. When specifying tinning, it is just as important to specify tinning type. Consider the requirements Tinning, today, is considered one of the of tinned copper for your particular application. best choices for wire that will be exposed to The most common tinning types, their makeup, corrosive or harsh environments, including and characteristics are described in the marine environments or industrial environments following table.

Tinning Types WHEN AND WHERE TO USE TINNING

Questions: Contact CMA If you have questions or are interested in speaking with us about a custom cable assembly, we are happy to help. Please contact us by email or phone.

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