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The ABCs of Deep Hole Drilling Technology

Deep hole drilling is a machining process that generates holes that can be up to 200 times longer than the diameter of the hole. It was invented before world war 1 for making gun barrels. Today this technology finds applications in over 15 different industries with 200+ different applications. Major Applications of deep hole drilling are as shown below.

Conventional drilling can handle Length / Diameter ratios of about 10 effectively. When holes get deeper, several limitations present themselves like Tool life, Surface Finish, Hole Straightness, Roundness, Chip Removal. Once the L/D ratio goes beyond 10 for drilling, deep hole drilling is required.  Major types of deep hole drilling processes are Gun Drilling and BTA Drilling.

Gun Drilling

Gun Drilling is a deep hole drilling process which is used for drilling long holes in diameters from 1 mm to 35 mm in size. Coolant ay high pressure is pumped through the tube and chips are evacuated from a V shaped flute along the length of the tube from the outside.

BTA Drilling

BTA Drilling (also called STS – Single Tube System) is a deep hole drilling process which is used for drilling long holes in diameters from 12 mm to 250 mm in size. Coolant ay high pressure is pumped from the outside of the tube and chips are evacuated from inside of the tube as shown below.

Applications in today’s industry demand drilling in exotic materials or hard super-alloys while maintaining accuracy and productivity. Maintaining straightness of holes with good tolerance and surface finish requires in-depth knowledge, expertise and experience in the process. Machine features, calculation and selection of process parameters, material input condition, tooling, coolant, filtration etc. have a profound impact on output parameters.

There are three different configurations for deep hole drilling as shown below. Selection of the appropriate configuration depends on the application requirements and the accuracies required for the same.

Output parameters for deep hole drilling technology are Hole Straightness, Hole Tolerance and Surface finish. The figure below explains these parameters clearly.

Precihole Machine Tools is a leader in providing hi-precision deep hole drilling and hole finishing technology. Our focus on this niche technology over the last three decades has made us a highly recognized brand with the most complete range of solutions offered in this technology. Our strength is to be creative and customize an engineering solution that is perfectly suited to the needs of the customer. Our business strategy revolves around customer success by combining a state-of-the-art machine tool, application support and excellent service together in our offering.  

Precihole Machine Tools provides complete solutions from A to Z in deep hole drilling technology.  Precihole has prided itself in being successful in every single project that it has undertaken over the past 30 years all over the world. Excellent customer references helped Precihole create a global brand that is admired and trusted by the industry.  Precihole continues to innovate and bring new products to market. Company strategy is to spend time learning new application requirements from customers and to invest in R&D. Precihole works very closely with tooling partners all over the world to ensure that the products keep up with new trends and developments in cutting tool technology. Upcoming pipeline of cutting-edge new products will continue to push the boundaries of this technology and energize the needs of the industry.

Precihole Machine Tools is headquartered in Thane near Mumbai, India and has offices in the United States as well as Europe. The company has three manufacturing facilities with total manufacturing space of over 150,000 sq. ft. Precihole exports its products and services to over 25 countries as more continue to come.