Drill round tools (Mining Industry Magazine, 2015)

V.V. Lyukhanov, Director of Machine-Building Holding JSC,
S.B. Alferov, Sales Director of Machine-Building Holding JSC
The uniqueness of the manufacturing technology of all MH JSC drilling tools lies in the fact that
all processes are systematized and organized using traditional and modern production
management methods. These methods are built in such a way that the influence of the human
factor on the quality of products is minimized. This conclusion was made based on the results
of repeated research and testing of products, including in the conditions of mining enterprises.
For more than 10 years, specialists from Machine-Building Holding JSC (Ekaterinburg) have
been successfully implementing their own developed program for manufacturing of import-
substituting products for the mining industry. MH JSC developments are mainly aimed at
facilitating the work of miners by enhancing productivity, reducing labor intensity, and also
increasing the service life of equipment. Most of the developments have been brought to
industrial operation and are successfully used at many mining enterprises in Russia and the CIS
countries.
Specialists from Machine-Building Holding JSC have mastered the technology of manufacturing
drill round bits for mechanized drilling with threaded connections R32, R35 and R38 of nominal
diameters 43, 45 and 51 mm. The main difficulties in implementing the project were connected
with coordination and approval of the relevant technological regulations in the working groups
of the enterprise and organization of cooperation with MH JSC adjacent and internal structural
divisions.
Housings for drill round bits are manufactured from high-alloy steel grades produced by Russian
metallurgical plants under special agreements that strictly regulate the tolerance for non-
metallic inclusions and harmful impurities. MH JSC employees additionally carry out the
incoming inspection of the steel supplied. It should be noted that for a long time it was believed
that domestic metallurgical enterprises were not capable of producing such steels for
significant alternating loads, and this problem was one of the limiting factors in the
development of many products in various sectors of domestic industry. After numerous
meetings and negotiations, the specialists of MH JSC managed to find mutual understanding
with the employees of metallurgical enterprises and agree on the regulations for the
production and acceptance of the necessary steels.
Machine tool builders developed various technical solutions for re-equipping existing machining
centers and acquiring new ones with special capabilities that take into account the specifics of
the technology for manufacturing drill round bits. For example, machining centers were
equipped with special bar loaders that made it possible to load bars for the entire work shift
with no operator engaged. The main requirement of MH JSC technologists for the processing
equipment was to arrange the possibility of turning the housings of drill round bits with
minimum amount of parts reinstallation. For this, machining centers with the special
configuration for the foundation and the spindle were introduced. This configuration allows to
process parts by turning, milling and drilling operations without removing them from the
machine. Machining centers were also equipped with the additional movable chuck, which,
after processing one side of the part in the stationary chuck without operator intervention, was
able to re-fix the product for processing the other side, etc.
Tool makers equipped machining centers with special cutting fixtures, which allowed to provide
the necessary processing accuracy and performance. MH JSC implements the mechanical
processing of drill round bits housings with the use of modern, high-precision and high-
technology equipment. Heat treatment is carried out using special modes that are developed,
approved and adjusted based on repeated laboratory metallographic studies, as well as the
results of numerous pilot and industrial tests.
Drill round bits housings manufactured by MH JSC are reinforced with carbide inserts with
increased wear resistance. MH JSC specialists select the optimally required configuration of drill
round bits housings as well as carbide tools for them for various mining, geological and
technical conditions.
In addition to manufacturing drill round bits, MH JSC specialists, according to numerous
requests from mining enterprises, managed to master the production of consumables
(couplings and shanks) for foreign hammer drills, the quality of which is significantly superior to
their imported counterparts. Consumables for imported hammer drills manufactured by MH
JSC are the optimal alternative for mining enterprises as part of import substitution. Currently,
measures are being taken to expand the production to increase the quantity and range of these
products.
The uniqueness of the manufacturing technology of all MH JSC drilling tools lies in the fact that
all processes are systematized and organized using traditional and modern production
management methods. These methods are built in such a way that the influence of the human
factor on the quality of products is minimized. This conclusion was made based on the results
of repeated research and testing of products, including in the conditions of mining enterprises.
The first tests of drill round bits KNSH 43-R32.BSр MH711.00 of nominal diameter 43 mm
(10 pcs.), KNSH 45-R32.BSр MH712.00 of nominal diameter 45 mm (10 pcs.) and coupling Т-38
MH780.00 (5 pcs.) manufactured by MH JSC were performed by “Shchit-Stroy” Company
(Ekaterinburg), which provides contracting services for tunneling works at mining enterprises in
the Sverdlovsk region. Similar drill round bits from a Japanese manufacturer and couplings from
a Swedish manufacturer were taken for comparison. The test results were recorded. Based on
the test results, the commission of specialists from “Shchit-Stroy” Company determined that
drill round bits and couplings produced by MH JSC showed higher durability than products from
foreign manufacturers: drill round bits KNSH 43-R32.BSр MH711.00 and KNSH 45-R32.BSр
MH712.00 – by 31 and 38%, respectively; couplings T-38 MH780.00 – by 30%.
Subsequently, industrial tests of drill round bits were carried out at many mining enterprises in
Russia and other CIS countries. The results are fixed in the test reports. All test results show
that the use of drill round bits produced by MH JSC is more effective than the use of similar
samples from foreign manufacturers.