Again, there is no general headwind limit. There may be a headwind limit for autoland (25 knots in the 747), but no general limit. In practical terms, as has already been pointed out, turbulence and other weather (rain, downdrafts, etc) will make it inadvisable to land when the surface wind is high, and may restrict ground operations before flight ops are restricted. I have landed in 50+ knot wind, but it is not a common practice for most commercial operators.