If the pattern design you have chosen calls for jointing, there are several different methods you may choose from. Usually, the pattern will state which method is recommended; but, since you are the one making the bear, you may choose whichever method you are most comfortable with.
String Jointing
A method used mostly with small miniature bears. All the parts of the bear are first sewn and stuffed. The limbs are joined to the body of the bear by running a strong thread from one limb, through the body and through the other limb. The thread is run back and forth this way until secure. The most common problem with this method would that if you swing the arms or legs around repeatedly in the same direction (which children tend to do!) will twist and tighten the jointing thread causing it to eventually break. This method is probably the simplest method of jointing.
The pop rivet is inserted through the joint discs using a special gun. Mostly used in manufacturing since once the rivet is in place, it cannot be removed. It is quick and permanent. Most bear makers prefer a more forgiving method.
Some more complex bears use more complex jointing systems and tools such as swivel neck joints (allows the neck to swivel and rotate), Loc-Line®, Flexlimb® (2 methods of allowing the limbs and body to bend and pose) or just have multiple joints at the neck or wrists or knees etc. These methods are wonderful to experiment with after youšve made a couple of bears. Most bears are jointed using hardboard discs, metal washers and one of three methods: cotter pins, tap bolts or setscrews.
Preparing Your Joints
In general, one of these 3 types of fastener (cotterpin, tapbolt or setscrew) is pushed through a metal washer and then a hardboard disc and then inserted into an arm or leg so that the end of the fastener is sticking out at the joint hole of the limb. The end is then pushed into the body at the correct joint placement hole. Another hardboard disc and then another metal washer are placed onto the end of the fastener inside the body, and the fastener is then tightened down.
Cotter Pins
The cotter pin is tightened by turning down each leg of the cotter pin into a coil (like opening a sardine can) using either a needle nose pliers or a special tool called a cotter key. Each leg of the cotter pin is turned away from the other.
Tap Bolts
Tap bolts are tightened by using a nut driver to hold the head of the tap bolt (so it doesnšt turn while you are tightening the nut onto it) while tightening a locknut onto the other end with a ratchet wrench.
Setscrew
A setscrew is a screw with no head on the end. One end has a hole in it and the other end is solid. Insert an allen key into the hole in the setscrew to hold it tight while using a ratchet wrench to tighten a locknut onto the other end. Now you can prepare your joint as described above and then fasten the second bolt onto the setscrew by tightening a locknut onto the end with the hole with a ratchet wrench while holding the setscrew tight by inserting the allen key into the hole.
The main advantages to using setscrews or tap bolts are the strength and tightness of the joints and the ability to tighten or loosen the joints without weakening the joint.
The main advantages to using setscrews or cotter pins is that you only need to have access to one end of the joint in order to tighten or loosen them. Putting a tap bolt in the head means having to leave an extra seam open to access the head of the bolt to tighten it. Similarly, if your bear's joints loosen with age, you need only to open the back of your bear and tighten all joints at once.