A Scalpel is a very sharp surgical instrument used to make incisions (cuts) in the skin or other bodily tissues. Scalpels are used in the body modification world for many different procedures, such as Scarification, Stretching, correcting placement of a Piercing, as well as for some of the more, such as Amputation.
Scalpels are used for a multitude of different applications and come in a great number of different shapes, a wide range of which is considered 'standard', and a further range of which are specialized for procedures ranging from eye and neurosurgery to dissection and autopsies.
Scalpel blades are most commonly made from Stainless Steel or Carbon Steel, but there are other, sharper alternatives to these widely used blades. Obsidian scalpel blades are being used with increasing frequency amongst surgeons. These stone blades are recognized as the sharpest blades in existence, producing a cutting edge of one molecule and are reportedly 500 times sharper than conventional Stainless Steel blades.
Disposable sterile scalpels with handles are very inexpensive (typically $1-2). Sterile scalpels without handles (you buy a handle separately) are so inexpensive that they may be disposed of after only one cut. Changing blades often for a lengthy scarification procedure may help minimize pain.
BMEShop, farm supply stores and certain websites (typically medical supply distributors on auction sites and comprehensive first aid kits on sportsman goods sites) may sell scalpels without question. Booths at BDSM fairs specializing in medical fetish equipment may have scalpels, as well.