Prong

Prong set­ting is the sim­plest and most com­mon type of set­ting, largely because it uses the least amount of metal to hold the stone, thus show­ing it off to its best advantage.

Gen­er­ally it is sim­ply some num­ber of wires, called prongs, which are of a cer­tain size and shape, arranged in a shape and size to hold the given stone, and fixed at the base. Then a burr of the proper size, is used to cut what is known as a “bear­ing”, which is a notch that cor­re­sponds to the angles of the stone.

The burr most often used is called a “hart bur” that is angled and sized for the job of set­ting dia­monds. That bear­ing is cut equally into all of the prongs and at the same height above the base.

Then the stone is inserted so that it goes into all of the bear­ings, pli­ers or a pusher are used to bend the prongs gen­tly over the crown of the stone, and the tops of the prongs are clipped off with snips, filed to an even height above the stone, and finished.

Usu­ally a “cup burr” is used to give the prong a nice round tip. A cup burr is in the shape of a hemi­sphere with teeth on the inside, for mak­ing rounded tips on wires and prongs.

There are as many vari­a­tions of prong set­tings as there are stars in the sky — 2 prongs up to 24 or more, many vari­a­tions involv­ing dec­o­ra­tion, size and shapes of the prongs them­selves, and how they are fixed or used in jew­elry. But the method of set­ting is gen­er­ally the same for all of them.