Soldering - which is better - 60/40 or 63/37 ?

I usually use 60/40.

Any preference for 63/37 and if so why? 63/37 has a bit more TIN in the mix, I think that raises the melting point a bit....no lead is safer for the environment, but I find lead free solder much harder to flow.

Thanks

As someone with 'all the gear but no idea', I had an awful time with some 63/37 "Model B-1"? Solder I bought from banggood. Consistent dry joints, "lumpy" finish (if that's even a thing), just frustrating to get it to go where I wanted.

Changed to Henknel/Loctite Savbit No.1 (Sn50% Pb49% 1%Cu) and had no problems ever since - it was much more expensive but I guess you get what you pay for!

Interested to see what others use, though

Edit to add: I keep most parts in a 'box of bits' to keep lead from going to landfill. Solder blobs etc get recycled to divert them from land-fill.

The reason for 63/37 tin/lead solder is that this ratio is very close to the eutectic, or minimum melting point of tin/lead alloy. It has minimal solid/liquid phase change at this point, and if your soldering tool and technique is good, you should get a cleaner, better solder joint.

The practical side is that 60/40 is so close it has little practical difference for most home users, so either should be fine. I stick to quality vendors Kester or Ersin electronic solder in wire form. Pastes for surface mount may be a different matter.

I find RoHS non-lead solder to be harder to work with, requiring higher temperatures generally, and a history of less reliability. As long as it's available, I prefer to work with tin/lead in my hobbyist quantities, and wash my hands. I don't have any experience with other alloys with silver, copper and other trace metals.

I use Kester 63/37 solder. Always use flux for a good joint. Old or cheap solder does not work for me. 63/37 solder changes from liquid to solid very quickly so there is little time for the joint to move while cooling. Lead-free solder is hard to use, requires special soldering tips (it is hard on a tip made for lead solder), and just does not stick when needed.

I put my Elekit TU8200 HiFi valve amp together with Kester 63/37. Beautiful stuff to work with, even for solder bridges. Forget lead free stuff, as others have said, inconsistent and difficult to use. Good quality 60/40 is ok as well. Unless you are chewing on it, I don't know that the lead content of either is a major health hazard, especially if you have a good fume extractor.

:tinfoil:

Lead free solder is not good for your health, but good for the environment.
For a hobbyist I would strongly advice against lead free solder. The flux in lead-free is more agressive (because it is harder to use than lead containing solder) and very bad for your lungs. Lead containing solder is fairly harmless for your health, as the lead does not evaporate. It also gives stronger and more reliable solder connections.

Personally I use 62-36-2 (Sn, Pb, Ag) solder because of the low melting temperature and nice shiny finish. Works great with SMD components and sensitive devices.

HotWire said:

I use Kester 63/37 solder. Always use flux for a good joint. Old or cheap solder does not work for me. 63/37 solder changes from liquid to solid very quickly so there is little time for the joint to move while cooling. Lead-free solder is hard to use, requires special soldering tips (it is hard on a tip made for lead solder), and just does not stick when needed.

Click to expand...

This is what I use, Kester is good stuff.

Hello OP, is your question related to flashlights or other lighting. If not I will probably move it to the non flashlight electronics forum.

Bill