The performance of an explosive cannot be expressed by means of a single characteristic parameter. Brisance is the destructive fragmentation effect of a charge on its immediate vicinity. The relevant parameters are the detonation rate and the loading density (compactness) of the explosive, as well as the gas yield and the heat of explosion. The higher the loading density of the explosive (moulding or pressing density), the higher its performance concentration per unit volume; also, the faster the reaction rate, the stronger the impact effect of the detonation.

Moreover, an increase in density is accompanied by an increase in the detonation rate of the explosive, while the shock wave pressure in the detonation front varies with the square of the detonation rate. Thus it is important to have the loading density as high as possible. This is particularly true for Shaped charges.

Kast introduced the concept of 'brisance value', which is the product of loading density, specific energy and detonation rate. Brisance tests are upsetting tests according to Kast and HeB; the compression of a copper cylinder is determined by actuating a piston instrument; alternatively, a free-standing lead cylinder is compressed by the application of a definite cylindrical load of the explosive being tested.