This review or guide is mainly for the Chinese made spring assist or assisted opening knives.  These are not $40 and up American made knives, so of course you should not expect the same quality.  The one you receive in the mail will very likely not be very fast opening, and the fit and finish will be sub par.  That said, there are a few adjustments you can make so your knife will be at least acceptable.  And if you lose one of these, no big deal, it's just a cheap Chinese knife.  The ones I bought were all under $10.  They were all slow, if they locked open at all; only one was fast opening out of the box - the one that was painted.  Black painted blade and liner.  The paint reduced the friction, and in an assisted opening knife, friction is the enemy.  The easy way to achieve faster opening is to loosen the screw that the blade pivots on.  But too loose and the blade will wiggle back and forth. Find a happy medium.  You will need an allen wrench or, preferably, a Torx wrench.  My knives all used a size 6 and size 9 torx wrench, and a H1.5 allen wrench.  (Harbor Freight, as well as ebay, has boxed sets with all these sizes.) You may be able to do with an allen wrench that's close.  The quality of the screws is also sub par, so some downward pressure may be necessary to get a good grip.  If you have threadlocker, apply some to the threads, especially the pivot screw thread, otherwise it may become loose over time.  If you want to go further, take the knife apart.  This is where the no. 6 torx will come in handy, for the handle screws.  Remember how you took the knife apart, as you will put everything together in the opposite order.  Use a clean, well lit work table.  Eventually you will uncover the spring, a squiggly shaped piece of wire.  The temptation is to open it up a bit to increase the tension, but I discovered that doesn't do much.  Instead, clean the grease off of it, if any.  Grease causes stiction.  If the spring or the housing it's in is rough, use a dremel tool or fine emery cloth to polish (not sand) it as much as possible.  Afterward, leave it dry, or apply a coating of the lightest, thinnest oil available, like a thread penetrating liquid wrench.  While you have everything apart, take a look at anything else that might be causing friction.  The little dimple at the end of the flat "spring" that locks the knife when it's closed REDUCES friction (after you push past it), contrary to what I stated in the previous update. So don't file it down. The only problem is that it mates to the opposing hole in the blade, and that causes friction.  This is to hold the blade in when the knife is closed, but it's not really necessary for this purpose.  The hole in the blade can be filled in with epoxy.  However, you can use a plier to bend the spring back a little, so it's not exerting so much pressure on the blade.  Sometimes, though, this will cause the blade to not lock properly, causing some play, so some experimentation will be necessary.  Assemble everything like it was before, and adjust the blade pivot screw in as tight as possible, without impeding blade movement.  If it's a bit tight, it will loosen up after a few actuations. Very thin oil, the thread penetrating kind mentioned earlier, will help.  Try to apply it only to the pivot shaft.  Now is a good time to sharpen the knife, it will need it.