# Silver-tin and bismuth-tin alloys, by melting point? **URL:** \ **Category:** Factual Questions\ **Created:** [February 3, 2013, 10:27pm UTC](https://boards.straightdope.com/t/silver-tin-and-bismuth-tin-alloys-by-melting-point/649262 "2013-02-03T22:27:45Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![Napier](https://avatars.discourse-cdn.com/v4/letter/n/ce73a5/32.png) [@Napier](https://boards.straightdope.com/u/Napier)\ **Post date:** [February 3, 2013, 10:27pm UTC](https://boards.straightdope.com/t/silver-tin-and-bismuth-tin-alloys-by-melting-point/649262/1 "2013-02-03T22:27:45Z")
I have a silver and tin alloy that melts at 221 C, and a bismuth and tin alloy that melts at either 140 or 190 C (the digit is a little unclear but probably a “4”). How can I tell the ratio of the metals, from the melt point? Are these eutectics? I hunted around for some web table or program that would give eutectics for various combinations of elemental metals but only found one here, two there, and not these. Is there a good web resource for this? Thanks! ---
**Author:** ![yoyodyne](https://avatars.discourse-cdn.com/v4/letter/y/a9a28c/32.png) [@yoyodyne](https://boards.straightdope.com/u/yoyodyne)\ **Post date:** [February 3, 2013, 11:51pm UTC](https://boards.straightdope.com/t/silver-tin-and-bismuth-tin-alloys-by-melting-point/649262/2 "2013-02-03T23:51:38Z")
Ag-Sn is 3.5% by weight Ag, Bi-Sn is 58% Bi by weight and melts at 138 C. > **[NIST\_LeadfreeSolder\_v4.pdf](https://www.metallurgy.nist.gov/solder/NIST_LeadfreeSolder_v4.pdf)** > > 2.12 MB ---
**Author:** ![Napier](https://avatars.discourse-cdn.com/v4/letter/n/ce73a5/32.png) [@Napier](https://boards.straightdope.com/u/Napier)\ **Post date:** [February 4, 2013, 3:40am UTC](https://boards.straightdope.com/t/silver-tin-and-bismuth-tin-alloys-by-melting-point/649262/3 "2013-02-04T03:40:58Z")
Oh, nicely done, yoyodyne! Thank you!