Soldering terminology

It is a known fact that the addition of antimony (Sb) to a Sn -Pb alloy increases its mechanical strength. However, this effect works only to a certain level of Sb content. In Sn-Pb alloys, the strength of the solder increases up to an antimony content of 6% of the tin content, especially against creep deformation. For example, a solder alloy of 60Sn - 40Pb corresponds to 60 x 0,06 or 3.5% antimony content . This is known as antimony effect.