TWIST DRILL GEOMETRY AND TERMINOLOGY: A REVIEW OF STANDARDS AND COMMON PRACTICES

Language: BGPages: 9–17

Anton Grozev, PhD Student

Dept. of Machine Tools & Manufacturing Department “Angel Kanchev” University of Ruse

ORCID: 0009-0001-0101-3773

E-mail: agrozev@uni-ruse.bg

Assoc. Prof. Aleksandar Ivanov, PhD

Dept. of Machine Tools & Manufacturing Department “Angel Kanchev” University of Ruse

ORCID: 0000-0002-1030-0352

E-mail: akivanov@uni-ruse.bg

Abstract: This article examines two key aspects - the geometry and terminology of twist drills. The first part is devoted to the definition and measurement of the side clearance angle α_f in accordance with ISO 3002-1:1982 and ISO 5419:1982 standards. The relationship among the planes P_f, P_r and P_p is described, along with the limitations of the physical measurement of α_f at the periphery of the tool. The need to use digital methods such as CAD modeling and 3D scanning is emphasized. The second part of the article emphasizes the problems arising from the widespread neglect of the terminology regulated in ISO 5419:1982 in scientific publications. Angle values without clarity about the plane in which they’re measured, the method or the source of the data is often encountered. This leads to difficulties in the interpretation and comparison of results, as well as to limited applicability in engineering practice. In conclusion, the paper highlights the need for stricter adherence to standardized terminology and for greater transparency in defining parameters and their origin.

Keywords: Twist drill geometry, twist drill terminology, ISO 3002-1, ISO 5419, side clearance of the major cutting edge

REFERENCES

DIN 338, 2006. Parallel shank twist drills, jobber series.
DIN 340, 2006. Parallel shank twist drills, long series.
DIN 345, 2006. Morse taper shank twist drills.
DIN 1412, 2001. Special point geometry.
DIN 1414-1, 2006. Technical specifications for twist drills of high-speed steel - Part1: Requirements.
DIN 1414-2, 1998. Technical specifications for twist drills of high-speed steel - Part 2: Inspection.
DIN 1836, 1984. Groups of tool application for chip removal.
DIN 6581, 1985. Terminology of chip removing - reference systems and angles on the cutting part of the tool.
ISO 235, 2016. Parallel shank jobber and stub series drills and Morse taper shank drills.
ISO 3002-1, 1982. Basic quantities in cutting and grinding - Part 1: Geometry of the active part of the cutting tools - General terms, reference systems, tool and working angles, chip breakers.
ISO 3002-2, 1982. Basic quantities in cutting and grinding - Part 2: Geometry of the active part of the cutting tools - General conversion formulae to relate tool and working angles.
ISO 3292, 1995. Extra-long parallel shank twist drills.
ISO 3438, 1975. Subland twist drills with Morse taper shanks for holes Prior to tapping screw threads.
ISO 5419, 1982. Twist drills - Terms, definitions and types.
Nacer, M., Sami, B., Abdelaziz, A., 2023. Contradictory effects of machining conditions on wear in the main cutting zones of the twist drill. https://doi.org/10.21203/rs.3.rs-2592343/v1
Saha, P.P., n.d. REDUCTION OF DRILLING BURR BY EMPLOYING A STEP DRILL OVER USING A TWIST DRILL.
Saputro, R.D.A., Sukardi, T., Wibowo, Y.E., Hardiyanta, R.A.P., 2020. The effect of twist drill angle and spindle speed on surface roughness in S45C steel drilling process. J. Phys. Conf. Ser. 1700, 012024. https://doi.org/10.1088/1742-6596/1700/1/012024

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