Lancing is a cutting process which uses oxygen supplied through a consumable steel pipe to pierce holes in metallic and mineral workpieces.
The process is based on the principle that the iron pipe burns at approx. 1200 to 2700 °C dependent on the burning iron-to-oxygen ratio. The burning iron pipe is then used to cut the metal using a gauging process.
The most important factor for process economy is a proper oxygen-to-lance material ratio. Since this process is dependent on burning of steel in another process called thermic lancing, a lance has a few steel wires running through the steel lance. Apart from creating economy these wires also facilitate reliable lighting of the lance
In most cases lancing is performed in a position perpendicular to the plate. In this case, particular attention has to be paid to slag removal. The ejected slag, therefore, has to be blown off continuously. Slag sticking firmly around the pierced hole can be easily removed by using a hammer and chisel or appropriate tools. Also to prevent slag from flowing back into the oxygen cylinder and causing a blast a slag back flow arrestor is used.
