Recently I went shopping for more electrical components and on my list was solder wire. I bought one reel of solder wire from an indigenous company called Oswal. It is a 60/40 tin:lead solder wire. The thing that I did not notice was that the label said 'Resin Cored', Rosin cored I know but what is this resin cored solder wire? Googling for answers I found none which detailed it. I searched for Resin which is:

In polymer chemistry and materials science, resin is a "solid or highly viscous substance," which are typically convertible into polymers. Such viscous substances can be plant-derived or synthetic in origin. They are often mixtures of organic compounds.

Now I used this wire to solder a few things and it behaves just like a Rosin core solder wire. So my question: Is this resin core different from Rosin core or is it just a rebranded version? There is one place I found similar wire being sold, if it helps: Resin core solder wire

  • \$\begingroup\$ Rosin/resin = flux \$\endgroup\$ – JIm Dearden May 27 '16 at 18:02
  • \$\begingroup\$ It's the same thing. Rosin = Resin = Soldering Flux. \$\endgroup\$ – DerStrom8 May 27 '16 at 18:04
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    \$\begingroup\$ It's more likely a misspelling or mis-translation than an actual new product. \$\endgroup\$ – W5VO May 27 '16 at 18:04
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    \$\begingroup\$ @AadityaSahay There may be other readers in the future with the same question. I would just leave the question alone. No need to delete it. \$\endgroup\$ – DerStrom8 May 27 '16 at 18:23
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    \$\begingroup\$ Thanks everyone, I thought that it was kiddish and thats why I thought of removing it, I now find that its not that kiddish therefore I shall not delete it. \$\endgroup\$ – Aaditya Sahay May 28 '16 at 6:09

"Rosin" is an organic-sourced subset of what is known as "Resin". It seems most likely that the word "resin" was used as a mis-spelling or mis-translation.

Ref: https://en.wikipedia.org/wiki/Resin#Rosin


Rosin or resin or flux core solder is used when soldering copper that is slightly tarnished. The flux cleans the surface of oils and contaminates and prevents oxidation until it cools off. Many companies wash off the flux with alcohol or toluene or a mixture of the two.

Low level commercial grade products may still have flux on the boards. Acid based fluxes are used for copper pipes and other highly tarnished surfaces. This type of flux should be removed when the work is done, if possible.


As a marine mechanic, resin core leaded solder is the good stuff for wiring in my experience. I couldn't tell you what the difference is between resin and rosin except they are not the same, resin is harder to find for some reason, and resin works a lot better.

  • \$\begingroup\$ If you had read the comments you would know that resin and rosin are the same. Likely they originate from separate countries. \$\endgroup\$ – user105652 Jul 26 '19 at 5:17

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