Catch Bit Info --- Hey folks, I know a few of you mentioned that there's some play in the catch bits, but that should be a non-issue. They're designed that way. The catch bit is designed to make that pocket a bit larger next to the adjacent blade, or to match thicknesses between two non-similar blades. The part you don't see, inside the knife, is cut parallel to the spring that it rides on top of. There has to be a gap between it and the spring that so that it doesn't interfere with the blade-spring relationship. Sometimes the gap may be a bit larger due to gauging the end of the spring, or gauging and dressing (smoothing) the tang.
Now lets look at the spring-blade relationship. When the blade is closed, the end of the tang and the kick are resting against the spring. The spring is actually pressing against the tang end, trying to press the blade further into the well, but the kick is preventing this from happening. This is what keeps that blade closed nice and tight.
OK, so you have a knife with a catch bit that was fitted tightly against the spring rather than with the requisite gap between them. And keep in mind that the catch bits are punched out to the same size, you can't custom fit every one unless you want to add a couple hundred dollars to each knife to cover labor costs. Everything works fine, the spring is pretty much right against the catch bit when the blade is closed. Now you use the knife, and find that after a number of sharpenings your blade tip is sitting a bit proud and you have to take a bit off the kick in order to drop the point back into the well. You take a bit off, close the blade,and to your horror it drops in just fine but isn't tight. It's floppy, easily pulled up about a sixteenth or eight of an inch before the tension starts. What happened? The act of filing the kick changed the geometry of the resting points on the spring. By filing the kick, that part of the tang pivots down farther, resulting in the round end pivoting up higher. In order to accomodate this the spring drops a bit, or moves closer to the pivot point. The only problem is the catch bit stayed right where it was, and the spring, rather than dropping against both contact points on the newly aligned tangs, is stuck against the catch bit, and you wind up with a floppy blade with no fix except to completely dismantle the knife and file some of the bit down to produce the needed gap. This can also happen at any time during production, since it's pretty much impossible to gauge and dress every single blade and spring end the same. Make a spring a hair too long, or wind up having to take a kick down a bit more than the others, and you get the same crummy result; knock the knife apart and hope you don't crack the covers in the process. So you see, that gap is absolutely necessary. Oftentimes the pin will expand in the hole and lock it in place so that the bit doesn't pivot, but more often than not it's to be expected. Hope this makes sense, it was mighty long winded.
Eric
