This standard specifies the technical requirements, test methods, inspection rules, marking, packaging, transportation and storage of two drill bits (hereinafter collectively referred to as "drill bits") for hydraulic rock drills in coal mines, namely, cross drill bits with corrugated threads (hereinafter referred to as "cross drill bits") and ball-tooth drill bits with corrugated threads (hereinafter referred to as "ball-tooth drill bits"). This standard applies to drill bits for drill tools used in hydraulic rock drills in coal mines. MT/T 516.2-1995 Drill bits for drill tools used in hydraulic rock drills in coal mines MT/T516.2-1995 Standard download decompression password: www.bzxz.net

Coal Industry Standard of the People's Republic of China
Drilling Tools for Hydraulic Rock Drills in Coal Mines
1 Subject Content and Scope of Application
MT/T 516.21995
This standard specifies the technical requirements, test methods, inspection rules, marking, packaging, transportation and storage of two types of drill bits (hereinafter collectively referred to as "drill bits") for hydraulic rock drills in coal mines, namely, cross drill bits with corrugated threads (hereinafter referred to as "cross drill bits") and ball-tooth drill bits with corrugated threads (hereinafter referred to as "ball-tooth drill bits").
This standard applies to drill bits for hydraulic rock drills in coal mines. 2 Reference standards
Terminology of rock drilling machinery and pneumatic tools
GB 6427
Carbide drill bits for rock drilling
GB6480
MT198 General technical conditions for hydraulic rock drills for coal mines MT/T516.1 Waveform thread of drill bits for hydraulic rock drills for coal mines 3 Terms
Drill bit life
The cumulative length of drilling holes from the start of drilling to the failure of the drill bit under the field or laboratory conditions specified in the standard (m). Full grinding life
Drill bit life measured by repeatedly grinding the carbide teeth (segments) until there is no residual residue when testing the drill bit life. Ungrinded life
Drill bit life measured by not grinding the carbide teeth (segments) when testing the drill bit life. 4 Technical requirements
4.1 The drill bit shall comply with the provisions of this standard and be manufactured according to the drawings and technical documents approved by the prescribed procedures. Drill bits with the same connection size shall be interchangeable.
4.2 The wave thread of the drill bit shall comply with the requirements of MT/T516.1. 4.3 The dimensions of the drill bit shall comply with the provisions of Figure 1, Figure 2 and Table 1. Approved by the Ministry of Coal Industry of the People's Republic of China on December 28, 1995 232
Implementation on May 1, 1996
Chamfering or chamfering
Figure 1 Schematic diagram of a cross needle
Drill bit type
Basic dimensions
4.4 The hardness of the drill bit body HRC35~55.
MT/T516.2—1995
To round or chamfer
Schematic diagram of ball-tooth drill bit
Allowable deviation
25 or 28
4.5The allowable weld defect at the root of the drill bit alloy sheet is less than 2mm, and the allowable weld defect at the side and top weld is less than 3mm; the cumulative allowable weld defect is less than 5% of the total weld length.
4.6The appearance of the drill bit is not allowed to have defects such as cracks, burrs, and corner loss. 4.7Under normal use conditions, the full grinding life of the cross drill bit should not be less than 200m, and the non-grinding life of the ball-tooth drill bit should not be less than 150m. 4.7.1 The cross drill bit is considered to be in failure when one of the following conditions occurs: a. The drill bit diameter is worn 2.5mm on one side;
b. The needle drill bit is partially peeled off or the trousers are cracked. 4.7.2 The ball-tooth drill bit shall be deemed to have failed when any of the following conditions occur: a.
Two teeth of the entire drill bit are broken or fallen off,
The diameter of the needle tip is worn 2.5mm on one side,
The drill body has cracks.
5 Test method
5.1 Visual inspection of the drill bit appearance and weld quality. MT/T 516.2—1995
5.2 The geometric dimensions of the drill bit shall be measured with measuring tools, standard templates, and special screw gauges. 5.3 The surface hardness of the drill bit body shall be tested in accordance with the provisions of GB6480. 5.4 Drill bit life test:
5.4.1 The test shall be carried out by continuous drilling on the coal mine rock tunnel excavation working face with a rock uniaxial compressive strength of 70 to 120 MPa or on a test bench with similar rock conditions.
5.4.2 The rock drill used shall comply with the provisions of MT198. 5.4.3 When inspecting the life of the drill bit, the hydraulic rock drill should be operated under rated working conditions. 6 Inspection rules
6.1 The inspection of the drill bit is divided into factory inspection and type inspection. The factory inspection is carried out by the quality inspection department of the manufacturer, and the type inspection is carried out by the product quality supervision and inspection agency.
6.2 Each batch of drill bits should be inspected before delivery and accompanied by a product quality inspection certificate. 6.3 Product type inspection should be carried out in any of the following cases: a.
Trial products of new products or old products transferred from the factory, when the product has major changes in structure, materials, and processes that may affect product performance, and when the products in normal production are sampled once a year, when the product has been discontinued for more than three years and resumed production; d. Www.bzxZ.net
When the national quality supervision agency puts forward type inspection requirements; when the factory inspection results are significantly different from the previous type inspection results. 6.4 The factory inspection and type inspection items of the product are shown in Table 2. Table 2
Inspection items
Technical requirements
Inspection methods
Inspection categories
6.5 Type inspection Each batch shall not be less than 3 pieces. The service life shall be the average of the service life of each sample under inspection. During factory inspection, the hardness test shall be sampled at 1% of the batch, but each batch shall not be less than 3 pieces. If there are unqualified products, double the sampling. If there are unqualified products again, double the sampling again. If there are still unqualified products after the second double sampling, the batch of products shall be judged as unqualified. Other items shall be inspected one by one. 7 Marking, packaging, transportation, storage
7.1 The outer surface of the drill bit shall be marked with the product trademark and model. 7.2 The drill bits of the same specification and model and the same material shall be packed in boxes, and the total weight of each box shall not exceed 30kg. The packaging box shall be sturdy and reliable. 7.3 The packaging box should be marked with:
manufacturing unit,
b, product name;
specification model;
quantity,
date of manufacture.
MT/T516.2—1995
7.4 The box should contain a product quality certificate. Indicate: a.
manufacturing unit;
product name,
specification model,
quantity;
date of factory inspection,
type inspection unit and inspection report number. 5. The drill bit should be treated with anti-rust treatment, such as copper plating, galvanizing, painting, etc. And it should be protected from moisture during storage and transportation. 7.5
Additional instructions:
This standard is proposed by the Technical Committee for Standardization of Coal Mine Special Equipment of the Ministry of Coal Industry. This standard is under the jurisdiction of the Mine Equipment Branch of the Coal Mine Special Equipment Standardization Technical Committee of the Ministry of Coal Industry. This standard was jointly drafted by the Beijing Mine Construction Research Institute of the China Coal Research Institute, the Hubei Wuxue Changjiang Tool Factory, and the Hubei Weining Mining Machinery Factory.
The main drafters of this standard are Xing Qinggui, Guo Xiaoxian, Wang Weihua, Peng Fuhua, and Feng Zhiyong. This standard is entrusted to the Beijing Mine Construction Research Institute of the China Coal Research Institute for interpretation. 235
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