Engineering steel merchant and value-added processing company Special Steels has announced that it has acquired Micron Technologies’ gun-drilling division to expand the capacity of its existing drilling division. Through the acquisition Special Steels will add two drilling machines, one being a HTT gun drill and the other a HTT BTA deep hole drill. The machines have been manufactured to German specifications, where the IP originated from, and come equipped for precision drilling with counter rotating tailstocks. Other high-end components and controls like the Siemens controls are standard.
“The acquisition of the gun drill enables Special Steels to offer precision drilling in the 10mm to 50mm hole size range over a maximum length of 2.3 metres, with these counter rotating machines,” explained Byron Ferguson, MD of Special Steels. Gun Drilling Tools
“Drilling of deep holes is increasingly in demand for numerous precision applications these days. In most cases it is not long production runs that are required but rather small to medium batches of 10 to 10 parts. The majority of machine shops will not have the capabilities to perform the task and invariably will have no idea as to where go to get the operation done.”
The HTT gun drilling machine that Special Steels has acquired
“Gun drilling is a very old process of drilling long or deep holes, first used in the making of gun barrels more than 100 years ago. Today’s technology with refined machinery and tool design has made gun drilling a reliable high production method for drilling short holes as well as deep holes. The gun drill consists of a hollow tube with a “V” shaped groove or flute along its length, and a carbide cutting tip designed in such a way as to produce its own guide bushing as it drills the hole. High-pressure coolant is introduced into the centre of the drill tube through the spindle of the gun drilling machine to help break and evacuate the chips along the “V” groove of the tool and out of the hole. Gun drilling provides very close tolerance straight holes with excellent surface finish. Gun drilling is able to produce holes as small as 0.78mm. On our machines the drill minimum is 8mm but at the moment we only have a 10mm drill so this is why we are operating in the range of 10mm to 50mm hole size.”
“Drilling deep holes is a discipline apart from drilling as most shops understand it. Holes that are characterised by the largest ratios of length to diameter require not only unusual machine tools, but also unusual allowances that more shallow holes don’t require. There are reasons, for example, why deep-hole drilling generally must be one of the earlier operations in any production process.”
“With conventional drills such as twist drills several cycles or pecks would be required to clear chips from the flutes of the drill. With a dedicated deep hole drilling machine and proper tooling and fixturing the hole can be produced in one pass. Depth to diameter ratios of up to 300:1 can be achieved and a good surface finish and hole size may eliminate secondary reaming, or honing operations.”
The machines have been manufactured to German specifications, where the IP originated from, and come equipped for precision drilling with counter rotating tailstocks. Other high-end components and controls like the Siemens controls are standard
“BTA drilling is a deep hole drilling process that uses a specialised drilling tool on a long drill tube to produce deep holes in metal, from holes with a diameter of 20mm and larger, up to depth-to-diameter ratios of 400:1. BTA drilling is the most effective method of drilling deep holes, as it is a cleaner, more reliable and capable process than conventional twist drills, and can achieve larger diameters and higher feed rates than the alternative gun drilling.”
“As mentioned before rifle barrels are an obvious component however long spindles, oil holes in shafts, bearings and connecting rods are other components that require deep hole or gun drilling.”
“Others are companies that supply pipes for various drilling projects in construction, geothermal engineering, water wells, mining and other sectors.”
“The machines can drill most materials and even drill surgical grade materials of titanium and stainless steel used in the medical industry. Other uses include mould making, die making, and the manufacture of combustion engine parts such as crankshafts and cylinder heads and woodwind musical instruments such as uilleann pipes.”
“Generally, a client will supply cut-to-length shafts or rods but there is also the possibility of gun drilling first and then cutting-to-length. It all depends on the customers’ requirements.”
The acquisition of the gun drill enables Special Steels to offer precision drilling in the 10mm to 25mm hole size range over a maximum length of 2.3 metres
“However, with our philosophy to transcend the essential ‘buy-cut-sell’ process, offered by many, we decided to rather explore the possibility of offering value-added services and minimising downtime over and above the required cut-to-size requirements. These benefits include machining preparation work to be done on the steel, reducing machine setup times, minimising material wastage and offering consistent dimensional tolerances for high-volume production. These processes would ultimately free up valuable time on our clients’ high-end machinery and allow them to perform the more complex machining operations that would add value to their manufacturing capabilities.”
“We decided to develop and invest in the tailor-made solutions and this has now resulted in Special Steels offering CNC machining services such as normal and deep-hole drilling, facing and centring, normal and robotic welding, laser, plasma and oxy-fuel cutting, tapping and bevelling, as well as hardness testing, ultrasonic testing, heat treatment, lab services and logistics.”
“The two machines we acquired are both manufactured by HTT, a company that has been dedicated to deep hole drilling technology since 1997. They have factories established in both Germany and China.”
“We are operating in a very niche area of the market and offer our clients the benefit of reduced setup time, better inventory management and fewer bottlenecks.”
Application Of Drilling Machine For further details contact Special Steels on TEL: 011 865 4939 or visit www.specialsteels.co.za