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Solder - 1/4lb Spool (0.020") Special Blend

We don't want to hype this solder TOO much, but this could possibly be the best solder in the world. There, we've said it. This is a special blend made specifically for us and we love it. It all started as a quest to find the best solder to use in our production process and ended up being the best we've tried. The best part is that it's lead free and has a water-soluble flux core.

This package contains 1/4lb of solder and has a diameter of 0.020" (0.5mm).

**Mix: **96.35% Sn (Tin), 3.0% Ag (Silver), 0.5% Cu (Copper), 0.15% Sb (Antimony).

  • [MSDS](http://cdn.sparkfun.com/datasheets/Tools/Part 4592 4593 - SDS - Indium Corp.pdf)

Solder - 1/4lb Spool (0.020") Special Blend Product Help and Resources

Core Skill: Soldering

This skill defines how difficult the soldering is on a particular product. It might be a couple simple solder joints, or require special reflow tools.

1 Soldering

Skill Level: Noob - Some basic soldering is required, but it is limited to a just a few pins, basic through-hole soldering, and couple (if any) polarized components. A basic soldering iron is all you should need.
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  • Got 0.020" and 0.032" spools today from a local supplier. Are they expected to splatter ? They make a sizzling noise and splatter very fine solder when I try soldering with the tip at 250c. I use SN100C in general and it doesn't splatter at all.

    Doesn't leave a shiny finish like leaded solder but that's expected - not super impressed with the splatter though.

    • That is probably from the flux core. That usually happens if your soldering iron is too hot. Obviously, performance varies with soldering irons and techniques, but I usually set my iron to 650 - 750 F depending on the tip. I do get a little bubbling/splatter, but it is mostly just the flux and not really any solder.

  • I love this solder, but the flux gives my wife an asthma attack. Could another version be made with MG Chemicals 8341 or something similar?

  • What do you guys recommend we set our soldering iron's temperature to when using this? I've been setting mine to 600°F (316°C), but the flux splatters a lot, which is unpleasant. Any useful tips?

  • The Sn/Ag/Cu content seems pretty typical, what's up with the antimony? I've seen that once or twice. Are there any toxicity concerns with it in the solder? CDC indicates that it's dangerous even in low levels.

    • Yeah, I read through these. Scary stuff. I've got some of this solder and I'm probably not going to use it now.
      I sent them an email asking for the MSDS sheets (post them?), however, I bet this, like many things on their site, is sourced from some shady place in asia that is not required to provide safety information.

      Edit: They emailed me and posted it. Props.

  • "according to the ATSDR and EPA, antimony is ranked below zinc, bismuth, copper, and silver (all of which are constituents of lead-free alloys), as well as lead, in terms of its potential threat to human health."

    "Antimony trioxide, used as a fire retardant, is toxic at .5 mg per cubic meter of air. However, antimony trioxide is not formed during soldering or reclamation processes."

    Quoted from A Study of Antimony in Solder

  • Just noticed something on the label; this is RoHS compliant as it contains no peanut butter. (Lead is Pb, not PB!) One tip: brush on some flux before reworking this solder. Great stuff.

  • This is the best lead-free solder that I have ever used, at any price. (You can pay less and struggle more if you wish.) It is also 0.02", which is much easier to use than the more common 0.03" diameters as it is easier to apply small amounts when necessary. I use a 15 Watt fixed wattage iron and it melts just fine (Hakko Dash 15W). Lower silver content solders require higher wattages and can produce more damage and scorch. The washable flux comes off easily, but does tend to blacken on the iron. It wipes off cleanly. The very low antimony content does not concern me - I don't eat the stuff.

  • I have done soldering since childhood but have only recently started to experiment with lead-free. It has been frustrating. I've been using a Sn/Cu mix from Radio Shack, and had some issues with the higher melting point, and a tendency to carbonize my tips. I got this in the hopes that it would be easier to use. I am not sure what I'm doing wrong, but it is much worse. The flux in this stuff is extremely acrid (much nastier to breathe at the same temperature) as the Radio Shack mix. It flows poorly and wets poorly, forming very high, peaked "beads" on my PCB solder pads. The frozen joints look much worse than the Radio Shack lead-free: they look like cold joints. Worst of all, the flux carbonizes on my iron tip instantly -- just one bit, and it has crusty black stains on it and its heat conductivity quickly plummets until after just a few joints it is unusable. That's starting after a thorough cleaning, and the black gunk is extremely difficult to get off -- wet sponge won't do it, dry sponge won't do it. I'm really disappointed. I'm experimenting with a temperature-controlled iron at temperatures in the range of about 700-800 F. The Radio Shack lead-free seems to work really well at about 740, allowing me to complete a connection in under ten seconds. This... doesn't. I'm cranking it up, and lifting pads, with the same iron. Am I supposed to need to douse everything with more flux? I haven't had to, working on these kits with other lead-free solders.

    I am planning to get myself a new Hakko soldering station after Christmas, and I'll see if those tips work better, but so far -- really disappointed and can't recommend. What is supposedly "better" about this solder?

    • I decided to stick it out and play with some different temps until finding something that didn't scorch so easily. Seems like the 600°F is pretty close to the sweet spot for this, where you can get some decent flow and not burn the stuff.

    • I have the same problems with this stuff that you're describing. I have a Hakko soldering iron, and at the default 750°F it just scorches the flux. This makes for some crappy joints, some bad fumes (I'm sure), and some nice black marks on my iron's tip that don't appear to come off.

      And, just like this member above, I'm sticking with the Radio Shack version. Perhaps I'll try playing with some different temperature settings, but in my opinion that should be part of the product description. I am personally very unsatisfied with this solder, or any solder that will burn and ruin my iron tips.

  • Does the antimony make it much easier to work with? I'd never heard of it, but the links pstemari posted two years ago make it look like pretty unpleasant stuff. If I wanted dangerous solder, wouldn't it be better just to stay with regular 60/40 leaded solder or the stuff you guys include in all the beginner kits? I've been using that well for nine months and find it very easy to work with, and I don't care about being RoHS compliant since I'm only making things for me, but I do have a one year old daughter, so I'd like to use something safer. Am I better off getting the ChipQuik solder that has the same Tin/SIlver/Copper ratio as this stuff but without the antimony?

  • Yeah this solder works great, with flux. Definitely clean your pcb "thoroughly" after. Using hot water scrub with short/stiff acid brush (to clean solder residue) then same with Isopropyl == 99% using a different acid brush (to clean flux). Wash hands before eating any food as solder and or flux can transfer into mouth causing irritable nausea syndrome convincing your wife that her cooking is as good as her aunts left foot. Take out the trash when your finished. (Timmy face) Ventilation should be required, as simple as soldering next to a window fan blowing out.

  • A word of caution about water soluble flux. If not cleaned off with water (preferably hot) it will leave residue on your PCB that can eat away at the copper and cause trace and component faults. It is even more noticeable on fine pitch SMT components. When I used it in the past we always ran boards through a dishwasher but you can't have non sealed parts on the boards like pots etc.

  • I started out soldering with cheap RadioCrack Pb-free solder, which I hated, then switched to 60/40 rosin-core, and from there to Ag-bearing, which I loved. I was skeptical about trying Pb-free again, but this solder is pretty damn good! I cranked the temp up to 800 °F on my Hakko, and it was relatively easy to work with. It doesn't seem to suck through holes as much as the leaded stuff (capillary action), and sometimes doesn't immediately wet the iron tip. With a little practice, however, your joints will turn out fine. The flux-residue cleans off nicely with distilled water and cotton swabs (no propan-2-ol, as others suggest, is necessary), for a beautifully shiny finished project. I would recommend this solder to others. For anyone who is unsure, try it out in the smaller quantity: https://www.sparkfun.com/products/10240

  • Got way more expensive than the last time I got it.. :(

  • How about a solder which is easy to clean but also uses a high resistance flux, so that thorough cleaning is not absolutely critical. It's just not feasible at times. Add to those specs "no clean" and you're making miracles happen :)

  • yep, great stuff. I have been getting excellent results and I'm no pro

  • Just wanted to check in and say that I can definitely vouch for this solder. I use it with the water-wash flux pen, which is a must if you're going to use this solder. I solder it at about 350 Celsius and plenty of the flux. Just gotta clean off your soldering iron frequently, or the flux burns up and leaves some black carbony stuff on the iron. It's easy to clean off, though, so no worries.

  • Coming from someone who's worked both with electronics and stained glass, I can honestly say that a eutectic leaded solder is the best to work with. While I haven't tried this specific solder, I have tried about every other lead-free solder and I always go back to leaded - it flows better, wets better and melts more uniformly. So despite a small environmental concern, I will continue to use and appreciate good leaded solder. Plus, I have no plans on throwing out my projects anytime soon and I always vacuum reclaim used solder.

    • I use a fluxless 96% tin / 4% silver solder and it wets the same as 60/40 Tin/Lead. I prefer not to use flux as it can leave a mess (and clean parts usually solder just fine without it).

      • From my training in the Navy as a 2M (Miniature/Microminiature) Tech I can tell you that 60/40 is not what he is talking about. He is talking about 63/37. With Eutetic Solder when it drops 1 degree it goes from liquid to solid. With 60/40 it has what we call a "plastic" stage where it is malleable and can turn into a problem.

  • I've used this type of solder before from a local supplier and I can confirm that it is indeed the best solder in the world!! Can't wait to get some, the local guys stopped selling it about 4 years ago.

  • It's nice to finally see a smaller size of this stuff, more affordable for us starving students. Thanks for the great offering guys! Also, the cool SparkFun logo adds to the street-cred, making it that much more desirable.

Customer Reviews

4.5 out of 5

Based on 8 ratings:

Currently viewing all customer reviews.

1 of 1 found this helpful:

Great lead-free choice

This solder melts easily, but holds a firm grip. Even with mediocre soldeing skills, some of my classmates' cold joints made using this solder have held in mechanical connections. Yet, it is still very workable and flows with ease compared to a 60/40 solder I used to use.

1 of 1 found this helpful:

Best lead free solder anywhere

I highly recommend this solder. It is the easiest melting, best flowing lead free solder that I have ever used. I especially like the 0.020" diameter, which makes flow control much easier. I used to introduce my students to soldering with 60/40 lead and felt bad about starting them out on the wrong environmental "foot". We regularly use this solder now with no more beginner's problems than we had with lead. I have also been able to use a cooler iron with this solder. (I have to be honest - any soldering has beginners' issues. Our students regularly burn the tips of their soldering irons. This solder's flux also scorches, but I'm not sure it is any more prone to this than any other.) Buy it!

1 of 1 found this helpful:

Great solder, but thinner would be great too!

This is excellent lead free solder, but I wish Sparkfun would also sell a smaller diameter version. When working on small pitch parts, I find it's hard to limit the amount of solder deposited. I'd love 0.010" and 0.015" diameter versions of this solder.

good product, gets the job done

not sure what else there is to say. flows pretty good for a lead-free solder.


Fantastic solder, I think it's the best I've ever used, the thickness(0.5mm) is perfect and it's so easy to use, it melts and flows easily, highly recommend. I've heard some bad things about lead-free solder, but this one is just AMAZING! I got it right the first time I used it, I think it will be a great option for starters, and for any one actually.

0 of 2 found this helpful:

better than most lead-free, but...

... it's still cumbersome to solder with it (for beginners, especially) as it doesn't flow with the same ease as tin-lead alloys.