prefered composition or brand of solder?

I need to get some lead free solder at work, i was wondering what you guys like as your prefered composition or brand

At digikey (where i buy everything) i ahve the choice of compositions of 96.5/3/.5 or 99.3/.7

What are you going to be soldering? Is there a chance that you would not know if tin/lead was used?

Sorry to say, but my favorite lead-free solder is nothing. I use good old 60/40 lead solder and love it. Hate that RoHS stuff!

Sn100E: https://www.electro-tech-online.com/custompdfs/2011/07/sn100e_pastefluxwire_rev1.pdf

nope i have to use un-leaded, otherwise it might contaminate the whole company!!! kidding but that is the fear.

you are all very opposed to the lead-free i see.

If you must, use the 96.5/3/.5. The silver will help prevent deplating of any component leads that have silver in their plating. The copper performs a similar function in both alloys while also reducing the melting point. You can read all about it at the Kester site.

https://www.kester.com/SideMenu/LeadFreeSolutions/tabid/145/Default.aspx

I prefer a SnPbAg alloy myself. Higher lead free soldering temperatures and extra nasty fluxes tear the plating off iron tips faster than you'd believe. Get serious about fume evacuation with that stuff too.

Yep. Opposed to lead free except for plumbing applications. 60/40 has been very common, but 63/37 is great for SMT work because the solidus and liquidus points are the same.