Drill string elements for hydraulic rock drills

In conditions of high competition in mineral commodity markets of ferrous and non-ferrous metals domestic mining enterprises are constantly taking measures to reduce costs for mining. A high share of costs is made up of expenses for imported drilling tools and spare parts for imported equipment due to a significant increase in the exchange rate of foreign currencies.
Under these conditions, mining enterprises are pursuing an active policy of import substitution to improve the efficiency of spending funds and increase the competitiveness of finished products. Mining enterprises act as a demanding customer and set tasks for domestic manufacturers to produce reliable, highly efficient mining equipment that is not inferior to imported analogues.

Machine-Building Holding JSC (hereinafter referred to as MH JSC) from Yekaterinburg has been implementing this task since 2009 by manufacturing drilling tools equal in quality and reliability to the best world’s manufacturers of such type of equipment. Over the past 10 years, more than 30 large enterprises in Russia, Kazakhstan, Ukraine, Uzbekistan, Kyrgyzstan and other neighboring countries have chosen MH JSC as the main supplier of drilling tools for high quality and timely deliveries. At the same time, there is a constantly growing high interest in the drilling tools of MH JSC from mining companies from far abroad, mainly from the African continent: Angola, South Africa, Zambia and other countries.
Industrial tests carried out in these countries have shown the high efficiency of using drilling equipment produced by MH JSC in comparison with previously used analogues from foreign manufacturers. Since 2015, along with the production of hydraulic hammer drill bits, specialists of MH JSC launched the production of drill string elements, namely connection couplings and shanks for hydraulic rock drills for production and tunneling. To develop these types of products, a comprehensive modernization of several metalworking shops, the heat treatment shop, and the metal science laboratory was carried out, as well as the necessary equipment was purchased and design documentation was developed. The production shops of the enterprise developed and mastered the relevant technological processes and trained the personnel.
We have mastered the production of shanks and couplings for all major models of hydraulic rock drills. The quality of the shanks and couplings manufactured by MH JSC is confirmed by numerous tests, and the key to the stable quality is the serial production of shanks and couplings for 5 years. Shanks and couplings confidently compete with foreign manufacturers in the market of hydraulic rock drilling tools.
In 2017, we started manufacturing of hydraulic rock drill rods for production drilling. This was preceded by a complex process of coordinating steels and pipe sizes with metallurgical enterprises. One of the mechanical sections and the thermal shop were modernized. Once again, the necessary equipment was purchased, design documentation was developed; The production shops developed and mastered the relevant technological processes and trained the personnel.

Today, MH JSC specialists have mastered the serial production of the entire line of hydraulic hammer drill rods for underground mining with threaded connections R32, T38, T45, T51, ST58, ST68 with a length of 915, 1220, 1525,1830 mm.

In the process of developing the market for hydraulic rock drill rods, a significant demand for fishing tools (taps, bells) was identified, since the ability to eliminate emergency situations when the drill string jams in difficult mining and geological conditions and extract the string from the well can significantly reduce the cost of hydraulic rock drill rods. In this regard, MH JSC specialists developed and mastered the production of the entire line of fishing tools for each standard size of hydraulic rock drill rods.

In the process of testing and industrial application of hydraulic rock drill rods produced by MH JSC, specialists from mining enterprises noted their high performance characteristics, such as:

• high resistance to distortion,

• no malfunction of rod elements,

• wear resistance of threaded connections,

• easy disassembling of the drill string.

In 2019, we launched the production of rods for tunneling. As part of the project, technical requirements for hollow hexagons are being coordinated with metallurgical enterprises. The Company's specialists carry out painstaking preparatory work for the next stage of production modernization: selection and acquisition of machining equipment, equipment for the heat treatment shop, and straightening equipment. As soon as the preparatory work for production modernization is finished and all the technological processes are mastered, we will implement the pilot and industrial tests for the tunneling rods under conditions of mining enterprises. The industrial application of tunneling rods manufactured by MH JSC at domestic mining enterprises will make it possible to implement the last missing element in production chain for hydraulic rock drill strings. This will make it possible to carry out complex deliveries of the entire list of drilling tools (shanks, couplings, rods, bits) for tunneling machines.
When mastering these technologies, the MH JSC specialists had to significantly improve their professional competencies, such as:

• determination of critical loads under various operating modes of shanks, couplings and rods,

• study of mechanical properties and selection of various steel grades,

• coordination of Technical Requirements for steels with metallurgical enterprises

• ensuring high pipe accuracy (quality of outer and inner surfaces, wall thickness, eccentricity),

• preparation of the technical process for processing parts to achieve the required accuracy and surface quality,

• selection of friction welding modes,

• selection of heat treatment modes to ensure high strength and wear resistance of products,

• building a quality control system at all stages of production using the latest measuring instruments,
• testing of rods, couplings and shanks in various mining and geological conditions.

Along with large mining companies, MH JSC actively cooperates with organizations that provide contracting services for drilling and blasting operations. These companies are actively involved in the process of selecting the most efficient mining equipment, test and commission new samples of drilling tools together with MH JSC specialists. We attribute such an active position of our partners primarily to their maximum interest in obtaining positive results from joint work.
Many mining enterprises and contracting companies have already been able to appreciate the advantages of working with the equipment manufactured by MH JSC, such as:
• high level of service,
• qualified technical support,
• consistently high quality of equipment and tools,
• short lead times for introducing new products into series production.