Political power grows out of the barrel of a gun, said Mao Zedong, and then proceeded to demonstrate how! Well, be it power or a projectile, the barrel of a gun needs to be drilled for anything to grow, and hence, the concept of a Gun Drill or a deep hole drilling machine. In fact, before the advent of gun drilling, gun barrels were hand forged (later roll forged) over a mandrel to form the 'tube'. But as the gun powder started evolving into more powerful avatars, this process was found wanting and against this background, gun drilling was first developed in Europe in the late 19th century, which makes it a work in progress for almost 150 years.

A "Deep Hole"is defined as one that is a minimum of 4 to 5 times its diameter in depth. As the Wikipedia describes: "Gun drills are straight fluted drills which allow cutting fluid (either compressed air or a suitable liquid) to be injected through the drill's hollow body to the cutting face. They are used for deep drilling - a depth-to-diameter ratio of 300:1 or more is possible. Gun barrels are the obvious example; hence the name". Precihole Machine Tools Pvt Ltd is one of the very few companies in India, and also the world, specialising in the design and manufacture of deep hole drilling machines - the complete range and the works. In fact in an age when companies describe themselves as total solutions providers, Precihole sticks to its core competency and proudly proclaims itself as the (w)hole solution provider!

Drilling & Finishing Techniques

There are four basic types of deep hole drilling techniques:

Gun Drilling - It consists of a carbide lug brazed to a kidney shaped tube and a driver at the other end. High pressure coolant is supplied through the tube to the drilling point and chips are evacuated from the hole through V shape single straight flute. This system is used for smaller holes, generally up to