Steel Drill Rods Alleviated (SDRA)
ТC 3668-707-01423949-03
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Steel Drill Rods Alleviated with Weld-on Tool Joints is used for drilling search and shallow exploration wells (up to 300 m).
These drill rods are the analogues of SUDR with Weld-on Tool Joints and differ from them that they have less weight owing to using the special thread (Sp.К) and the reduced wall thickness.
Having the reduced weight as compared with the Light Alloyed Drill Rods (LADR) and owing to the exposed hardening of the body SDRA combine in themselves advantages of drill rods SUDR and LADR and unlike the last ones can be successfully used in complex geological-technical conditions, especially during drilling in soils of increased abrasiveness.
Drill rods are made of steel 45, tool joints are made of steel 40XH (according to the coordination with the customer tool joints can be made of steel 40Х).
Production technology of SDRA is the same as the production technology of SUDR: the body of the rod passes the exposed quenching with High Frequency Currents (HFC) (except SDRA with diameter 24mm), weld-on tool joints are undergone to the volumetric heat treatment, chemical thermal treatment (carbonitration) and the following quenching with HFC.
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Drawing 2 – Steel Drill Rods Alleviated (SDRA)
Table 4 – Technical characteristics of SDRA
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Marking-off
standard size
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Basic dimensions, mm
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Special tapered thread
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Length of the rod in the assembly L, m
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Calculated mass of the rod, kg
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Moment of the threading joint’s balk, Newton ´ meter (±5%)
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Body of the rod
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Tool joint
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Outside diameter D, mm
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Wall thickness S, mm
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Outside diameter D1 , mm
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Inside diameter d, mm
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SDRA - 24
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24
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2.5
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24.5
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9
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Sp.К-18
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0.83
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1.42
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100
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SDRA - 34
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34
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3.5
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34.5
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16
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Sp.К-27
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1
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3.29
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500
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SDRA - 43
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43
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3.5
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43.5
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22
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Sp.К-34
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1
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4.18
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1000
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1.5
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5.88
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3
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11.0
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SDRA - 55
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55
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3.5
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55.5
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32
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Sp.К-45
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1
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5.95
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1800
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1.5
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8.17
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4.5
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3
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14.83
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1800
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Table 5 – Mechanical properties of the drill rod’s body and the tool joint
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Meanings of parameters
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The body of the drill rod
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Details of the tool joint
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group of durability D (steel 45)
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Steel – 40XН
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Temporary resistance σtemp, Mega Paskal
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539(55)
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882 (90)
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Yielding (fluidity) σyielding, Mega Paskal
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323 (33)
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686 (70)
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Relative elongation, %
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12
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15
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Hardness of the core, HRC
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-
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26
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Note:
1. Mechanical properties of the material of the drill rod’s body are shown after the normalization and it is spread
for the weld-on seam.
2. Mechanical properties of the details’ material of tool joints are shown after the valuable thermal treatment
(increasing).
3. Exposed hardness after the quenching with High Frequency Currents(HFC):
Body of the rod –min 40 HRC
Tool joint’s details- min 55 HRC
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