On the sparkfun page it says,
This is for a strip of 20 crimp pins. We regularly use a pair of needle nose pliers and a soldering iron to attach these pins.
If you use this method, you should be able to use a wide range of wire gauges, except as noted,
wire with thick insulation. I almost always use ribbon cable with these pins, so 28 gauge. Also,
like sparkfun indicates, I usually apply a dab of solder to hold the connection firm.
Also, with the non-$350 tools, I find it helps to do a "triple"-crimp. First, use the needle nose
pliers to do initial shaping, then use the wider channel of the crimp tool to shape the overall
crimp, especially useful for forming a nice rounded shape over the insulation part, and then
use the narrow channel to tighten down the final crimp.
Note that some of the crimp tools have a "rib" in one-half of the channel, and that rib should
be positioned over the part of the pin that crimps the wire, not over the insulation part [as I
understand it].