O.K. The AMP crimpers for P.I.D.G. (Pre Insulated Diamond Grip) terminals have two crimping areas. That for the electrical connection is like this "()" (except that one side of the die is closed on one half, and the other closed along the other half, so the dies open look like this (view with a fixed pitch font like Courier to avoid distortion and confusion): _ _______ |__ |__ (__ )__ _______| |_
so the wire part is crimped between the parens, and the sides keep the insulation from squishing out the sides.
And -- the insulation grip part is crimped with a section more like this (different scale to allow drawing it with ASCII graphics -- again use a fixed pitch font) _________ |___ |__ / \ \___ /___ _______| |_
which produces a diamond-shaped crimp on the insulation grip only.
There are pins holding the halves of the dies with three sets of mis-aligned holes -- your choice of a hole selects which size of insulation the grip will hold properly. Set it too tight, and it squishes out the larger diameter insulations. Set it too loose and it does not firmly grip the insulation
And of course -- this is only barrel style terminals. There are also (uninsulated) "flag" style terminals, in which the flags are bent into 'U's and the ends of the flags dig into the stranded wire. The crimp looks somewhat like this: _ / ) \_)
with the left hand side actually being a continuous curve, but I don't have oversized parens in the ASCII character set. :-)
These flag type crimp terminals are most often used in pins which crimp to the wire and then insert into the connector shell. Perhaps the most common ones are the pins for the DB-25 serial port connectors for RS-232, but there are larger ones for other different connectors, including the Molex ones, and AMPs own design of similar molded connectors. The crimpers from AMP for these various sizes will all say "Type F" rather than "P.I.D.G." or something similar.
The better ones have two sets of flags -- one for the wire connection and another for insulation strain relief -- and the insulation strain relief usually closes to close to a circle instead of the "flag ends in" pattern used for the connection part.
Note that *all* of the above are for *stranded* wire. Solid wire needs a different crimp style to make a reliable connection. And I normally don't use solid wire in combination with crimp terminals.
*That* is where the ratchet controlled crimpers win. You *can't* either mangle the right size terminal or crimp it too lightly. (Well, you *can* mangle it if you don't set it deep enough into the crimper so the connection crimp part misses the connection barrel. :-)And this is not the best style for insulated crimp terminals.
BTW When you are using crimp terminals, you want the insulation stripped just the right length. With the insulation fully bottomed in the terminal, there should be just the very end of the wire extending out the flag or ring end of the terminal. If it is back inside the crimped terminal a bit, it is not properly crimped.
Yes -- there are places were crimp terminals can't be used, and solder is the right way to go.
And when stripping the insulation, a trick to avoid the ends of the wires fraying out is to just start the insulation off the wire, then note which direction the wire twists (yes, each batch is likely to be different from the previous batch), and twist the insulation in that direction as you pull it off. This causes the strands to lay tight, which is an assistance when putting the wire into a crimp terminal (having a strand point back beside the insulation is the same as crimping an undersized wire), as well as the ability to solder the tip together to prevent fraying under a terminal screw.
Or -- if you use anti-wicking tweezers you can keep just enough length unsoldered, and have the rest tinned, where you can then form the tinned section into a hook, hook it through a terminal eye (e.g. on a tube socket) squeeze it with needle noses for a good firm grip, and then flow solder once you have all the wires on that terminal.
For solid wire, not for stranded, IIRC.
Note that this design is intended to be a field repair tool, not a production assembly tool.
And aside from the ones which have the notched blades for each size of wire, for smaller wire this a similar one called the "Nickless", which has semi-soft plastic jaws which form around the wire and strip without nicking the wire. (Nicks are likely to make the wire more likely to break with vibration.)
Those temperature-controlled irons are particularly nice when dealing with soldering transistors or IC (to avoid over-heating), or when soldering to printed circuit traces, because too much heat will float the traces free of the board -- especially with the older (and cheaper) phenolic boards. G-10 glass epoxy is a lot better with heat, of course.
What about a solder pot for tinning a bunch of just-stripped wire ends at once?
Enjoy, DoN.