Drill Feed Research Articles

Interaction of Mechanical Characteristics in Workpiece Subsurface Layers with Drilling Process Energy Characteristics

The performance properties of various types of parts are predominantly determined by the subsurface layer forming methods of these parts. In this regard, cutting processes, which are the final stage in the manufacturing process of these parts and, of course, their subsurface layers, play a critical role in the formation of the performance properties of these parts. Such cutting processes undoubtedly include the drilling process, the effect of which on the mechanical characteristics of the drill holes subsurface layers is evaluated in this study. This effect was evaluated by analyzing the coincidence of the energy characteristics of the short hole drilling process with the mechanical characteristics of the drilled holes’ subsurface layers. The energy characteristics of the short-hole drilling process were the total drilling power and the cutting work in the tertiary cutting zone, which is predominantly responsible for the generation of mechanical characteristics in the subsurface layers. As mechanical characteristics of the drill holes’ subsurface layers were used, the microhardness of machined surfaces and total indenter penetration work determined by the instrumented nanoindentation method, as well as maximal indenter penetration depth, were determined by the sclerometry method. Through an analysis of the coincidence between the energy characteristics of the drilling process and the mechanical characteristics of the subsurface layers, patterns of the effect of drilling process modes, drill feed, and cutting speed, which essentially determine these energy characteristics, on the studied mechanical characteristics have been established. At the same time, the increase in the energy characteristics of the short-hole drilling process leads to a decrease in the total indenter penetration work and the maximum indenter penetration depth simultaneously with an increase in the microhardness of the drilled holes’ subsurface layers.

Design of a Tree Micro Drill Instrument to Improve the Accuracy of Wood Density Estimation

To improve the estimation accuracy of wood density and study the linear correlation between drill feed resistance and wood density, a new micro drill instrument prototype that can simultaneously measure the rotation resistance and feed resistance of the drill needle was designed. The test tree species included hard and soft broad-leaved trees and coniferous trees, and the absolute dry density of each wood sample was measured. The drill resistance data were tested by our newly proposed prototype and a Resistograph 650-SC, and four linear models were established to define the relation between drill resistance and the absolute dry density of the wood. The results showed that (1) the statistical indicators of each model for our proposed prototype were better than the corresponding indicators of the Resistograph 650-SC for three of the four species tested; (2) the coefficient of determination of the linear regression model between the feed resistance of our proposed prototype and the absolute dry density of wood was 0.946; and (3) the statistical indicators of the model that included rotation resistance and feed resistance were better than those of the model that only including rotation resistance. Although the proposed prototype produced a competitive level of accuracy and explicitly demonstrated that including feed resistance improved wood density measurement accuracy, the prototype should be considered a first iteration as further hardware design changes and in-forest performance assessments across wider diverse set of test species are required before a conclusive evaluation can be rendered.

The Effect of Training Methods and Hand Eye Coordination on the Accuracy of Backhand Drive in Table Tennis Athletes

This study aimed to analyse the effect of the two-way and random feed drill training method on the accuracy of the backhand drive of PTM barokah Jaya Purwokerto, table tennis athletes. This study used an experimental method with a 2x2 factorial design and data analysis techniques using Analysis Of Variance (ANOVA) at the significance level (α: 0.05). The population in this study were PTM Barokah Jaya Purwokerto table tennis athletes, totalling 28 people. The results of this study: There are differences in the effect of the random feed and two-way drill training methods on the backhand drive. Two-way bait drill exercise is better than unexpected bait drill on the accuracy of backhand drive PTM Barokah Jaya Purwokerto table tennis athletes. There are differences in the effect of high and low hand-eye coordination on the accuracy of the backhand drive. Athletes with high hand-eye coordination are better than athletes with low hand-eye coordination against PTM Barokah Jaya Purwokerto table tennis athletes. There was no interaction between training methods and hand-eye coordination on the accuracy of backhand drives in PTM Barokah Jaya Purwokerto athletes. The conclusions of this study are 1). The two-way feed drill training method is better than the random feed drill. 2). Players with high hand-eye coordination are better than those with low hand-eye coordination. 3). there was no interaction between training methods and eye-hand coordination on the accuracy of the backhand drive of PTM Barokah Jaya Purwokerto table tennis athletes.

Regression and ANFIS-based models for predicting of surface roughness and thrust force during drilling of biocomposites

Biocomposites are increasingly being applied in the automotive industry. For assembly purpose, drilling process is often performed in these biocomposites parts to produce holes. The machining behavior of biocomposites is affected by the matrix, the reinforcements (nature and size), by the cutting conditions and the mechanical properties of biocomposites. Some of the newly developed biocomposites are made of a polypropylene/polyolefin blend matrix, which has low thermal conductivity and low softening temperature. Therefore, the selection of cutting parameters should be done with care to avoid thermal-induced damages occurred during drilling biocomposites. Also, due to the heterogeneous and anisotropic properties of biocomposites, it is essential to develop models for predicting the effects of these factors on the machining process performance indicators. In this research work, a full factorial design is used to investigate the effects of machining parameters (feed rate, drill diameter, spindle speed, and reinforcement type) on machinability indicators during the drilling of the three new biocomposites: Polypropylene/Polyolefin matrix reinforced with biocarbon particles and/or miscanthus fibers. The regression and ANFIS-based models are established for predicting thrust force (Ft) and surface roughness (Ra) based on empirical data. The results obtained show that, for each tested biocomposite, the proposed ANFIS models have better predictive accuracy for thrust force and surface roughness than the regression-based models. Furthermore, the drilling parameters and reinforcements used in these biocomposites considerably affect their machinability.

Modeliranje veštačkih neuronskih mreža podstaknuto Pajtonom kod bušenja kompozita ojačanih vlaknima stakla, konoplje, lana

As composites are materials whose properties can essentially be customized to suit the necessities of the engineering application on hand, they are being widely used in many applications for radically different purposes. In order to ensure quality in production process of composite products, a solid understanding of the process involved during its manufacturing is essential to ensure the product is free from both internal and external defects. To that aim, a study was conducted to model Thrust force and Torque on drilling of Glass-Hemp-Flax reinforced polymer composite by fabricating and maching the composite as per Taguchi's L 27 Orthogonal Array. The process parameters considered for modeling are drill diameter, spindle speed and feed rate. Using the process control parameters as inputs and thrust force and torque to be predicted as outputs, artificial neural networks (ANNs) were created to model the effects of the inputs and their interactions. The predictions obtained from the neural networks were compared with the values obtained from experimentation. Excellent agreement was found between the two sets of values, establishing grounds for more extensive use of neural networks in modelling of machining parameters.

Surface integrity studies for straight and inclined hole in micro-drilling of thermal barrier coated Inconel 718: A turbine blade application

Drilling micro-holes at different orientations on thermal barrier coated Inconel 718 superalloy surface is essential to protect turbine blades while operating in harsh environment. This work analyses integrity of micro drilled (600μm) surfaces on thermal barrier coated Inconel 718 sheets using TiAlN coated carbide micro-drills. Considering spindle speed, drill feed, and workpiece inclination, the drilling experiments were performed under dry environment with 100μm pecking length. Results show that, a higher tool life in terms of drilling length was observed in straight hole drilling at a combination of low speed (1000 rpm) and low feed (3μm/rev). The drilled surface roughness increased with the number of drilled holes and the highest value of roughness was observed to be 1μmRa on the 13th inclined hole surface. Smaller cavities were observed on the thermal barrier zirconia coated surfaces. In addition, drilled hole surfaces on metal showed alterations such as adhered chip particles and smeared material. Tensile residual stresses were observed in hoop direction and were found increase with the number of hole drilled in both straight and inclined surfaces. The highest compressive residual stress (1075.3 MPa) was observed in the axial direction on the 5th hole surface for inclined hole drilling, which shows an increase in the d spacing between two planes of machined surface.

A look back, part II: The drilling campaign of the Curiosity rover during the Mars Science Laboratory's second and third martian years

The Mars Science Laboratory (MSL) rover, Curiosity, completed its second Martian year, 1337 sols (1374 Earth days), of operation on May 11, 2016, and its third Martian year, 2006 sols (2061 Earth days), of operation on March 28, 2018. During this time the rover successfully drilled twelve full depth drill holes into the Martian surface and analyzed the recovered material using onboard instruments, giving us new insights into the potential habitability and geologic diversity of ancient Mars. During the second Martian year, four holes were drilled into the mudstones of the Murray formation: ‘Confidence Hills’ (Sol 759), ‘Mojave 2’ (Sol 882), ‘Telegraph Peak’ (908) & ‘Buckskin’ (Sol 1060); while four more holes were drilled into the sandstones of the Stimson formation: ‘Big Sky’ (Sol 1119), ‘Greenhorn’ (Sol 1137), ‘Lubango’ (Sol 1320) & ‘Okoruso’ (Sol 1332). During the third Martian year, four additional holes were drilled into the Murray formation: ‘Oudam’ (Sol 1361), ‘Marimba’ (Sol 1422), ‘Quela’ (Sol 1464) & ‘Sebina’ (Sol 1495). In this paper, we will give a brief overview of the rover sampling hardware and nominal drilling protocols, followed by a discussion of how these protocols were refined and altered early during the course of Curiosity's second year on Mars. In addition, we will describe the ‘Bonanza King’ (Sol 724) drill campaign, the mission's first ‘successful failure’, and how it influenced these changes. We will also briefly discuss the events leading up to the drill feed fault on Sol 1536, which resulted in suspension of all drill activities for the remainder of the third Martian year. Finally, we will present scientific highlights obtained from each drill site utilizing MSL's onboard instrumentation (SAM & CheMin), results enabled by the drill's ability to excavate sample at depth and transfer it to these instruments.

Control of Chip Formation and Improved Chip Ejection in Drilling With Modulation-Assisted Machining

Abstract Drilling with modulation-assisted machining (MAM) superimposes a low-frequency oscillation onto the drill feed motion. The otherwise continuous cutting in the drilling process is converted into a series of discrete cutting events. The result is a discrete chip formation process and concurrent improvement in chip ejection. The discrete chip formation and ejection in drilling with MAM were investigated via systematic experiments in OFHC Cu and Ti6Al4V using a two-flute twist drill and a single-flute gun drill. Drilling thrust force and chip morphologies for various modulation conditions are examined. The continuous cutting and discrete cutting regimes of modulation-assisted drilling are compared with conditions determined by a kinematic model. The results show that chip formation in the continuous cutting regime with MAM can influence chip breakage by random fracture at thin sections of the chip, but in this regime the resulting chip size is variable and not controlled. In contrast, when MAM conditions operate in the regime of discrete cutting, the deformed chip size can be directly controlled. The ability to control the chip size improves chip ejection and drilling process stability. A set of modulation conditions for enhanced performance of chip ejection are proposed. The study shows that modulation-assisted machining offers distinct advantages as a method for deep-hole drilling applications.

Experimental Evaluation for Improving Multiple Quality Characteristics of Drilled Holes: A Case Study on Drilling of Ti6Al4V

Titanium alloys find increased applications in many engineering fields such as bio-medical, aerospace, electronics and automobile industries due to their superior physical properties such as high specific strength, weight to strength ratio, corrosive resistant and toughness. Low thermal conductivity of titanium alloys makes it difficult to machine since high cutting temperature is generated at tool work piece interface. As it is highly chemically reactive at high temperature, work piece is adhered to the tool surface. The present work aims at investigating the effect of drilling process parameters viz. spindle speed, drill bit diameter and feed rate on machining performance measures such as burr height at entry and exit, surface roughness and circularity at entry and exit. In order to optimize all the performance measures simultaneously, the present investigation utilizes a hybrid approach known as superiority and inferiority ranking method combined with technique for order preference by similarity to ideal solution (SIR-TOPSIS) to convert these characteristics into single equivalent characteristic ([Formula: see text]-flow). A statistically valid empirical relationship is developed for r-flow in terms of machining parameters using nonlinear regression technique. The study aims at attaining optimal parametric setting that maximizes [Formula: see text]-flow. To optimize [Formula: see text]-flow, an improved version of meta-heuristic evolutionary algorithm known as harmony search (HS) algorithm is implemented. The confirmatory experiment suggests the robustness of the methodology in optimizing the drilling operation.

Use of drilling performance to improve rock-breakage efficiencies: A part of mine-to-mill optimization studies in a hard-rock mine

In a hard-rock mine, blasting is an important rock-breakage process that impacts energy consumption both in downstream comminution processes and mine productivity. Optimizing the blast fragmentation to improve rock-breakage efficiencies during crushing and grinding is key to mine-to-mill (MTM) optimization. This study explores the use of monitoring while drilling (MWD) data to achieve this goal. Representative penetration rates (PRs) were extracted from blastholes to estimate intact rock properties and predict the breakage efficiencies that directly affect comminution energy consumption. Two intact rock properties, tensile strength (TS) and Bond work index (BWI), were correlated with the PR data to predict these efficiencies in crushing and grinding, respectively. Because of the complexity of the raw MWD data and effects of various disturbances, the MWD data was preprocessed and normalized to achieve a representative PR value at each blasthole. This preprocessing entailed defining valid PR ranges from the MWD data that could eliminate the noise related to discontinuity features in the rock mass structure as well as errors in operator behaviors. The PR data was also normalized using the adjusted penetration rate (APR) to minimize the effects of mechanical factors such as drill feed force, torque, and rotational speed. To correlate the representative APR value with intact rock properties, TS and BWI, various laboratory experiments were conducted: drilling tests using a high-precision coring machine, Brazilian disc tests, and Bond grindability tests. Based on the results of these experiments, models were developed to predict rock-breakage efficiencies during crushing and grinding based on APR. The result of this study can be used to obtain blast energy designs that consider comminution energy consumption and efficiency in the downstream rock-breakage processes.

Influence of Rutile Nano TiO2 on Thrust Force, Mechanical, Wear and Microstructural Behavior of Al–SiC Composites

We studied microstructure, mechanical and wear properties of Al6061 SiC reinforced with Rutile Nano TiO2 (1, 2 and 3 wt%) composites. Al MMCs were fabricated by stir casting process and strength of the composite was measured by thrust force using drilling process. Drilling parameter, such as drill diameter, speed of spindle and feed rate produced thrust force on Rutile Nano TiO2 reinforced Al–SiC Composite. Results indicated that thrust force increased due to increased feed rate and drill diameter and was reduced by increasing the spindle speed. Surface of drilled area of given composite was investigated by using Scanning Electron Microscope (SEM) and Atomic Force Microscope (AFM). Tensile, Compressive and Micro hardness were found to increase (16.2%, 33.2% and 22%) by increasing the Nano TiO2 in Al–SiC composites. Moreover, it was also observed that density (2.66%) and impact strength (22.4%) also decreased. Wear test was conducted using pin on disc method and the result showed that the wear rate (14%) was decreased by adding Nano TiO2. Wear tested composite was examined by SEM and indicated that abrasive, cavity, fragmentation and oxidation were the predominant wear mechanisms.

Impact of drill bit feed rate and rotational frequency on the evaluation of wood properties by drilling resistance measurements

ABSTRACTIML-Resi PD-400 drilling tools (IML System GmbH, Wiesloch, Germany) were used to study the influence of the feed rate and the rotational frequency of the drill bit on the drilling resistance (DR) measurements. The study presents theoretical aspects concerning chip formation, kinematics (speeds, cutting angles, chip thickness) and cutting forces distribution during the drilling process. Drill bit rotational frequency and feed rate have an impact on nominal chip thickness or a feed rate per major cutting edge of the drill bit, and were correlated to DR measurements. Varied rotational frequency and feed rate had a significant impact on DR and feeding resistance (FR). Positive correlations between feed rate per major cutting edge and DR (FR) for the individually tested wood species can be described by allometric functions (R2 = 0.93–0.99). Wood density had a partial impact on correlations between feed rate per major cutting edge and DR (FR).

Combined effect of wood moisture content, drill bit rotational speed and feed rate on drilling resistance measurements in Norway spruce (Picea abies (L.) Karst.)

ABSTRACT An IML-RESI PD 400 drilling tool and a standard spade drill bit (IML System GmbH, Wiesloch, Germany) were used to study the combined effect of wood moisture content (MC), drill bit rotational speed and feed rate on drilling resistance (DR) and feeding force (FF). Tests were made with Norway spruce (Picea abies (L.) Karst.) conditioned in a normal climate (20°C/65% RH), at 20°C/95% RH, vacuum-pressure impregnated in water, and oven-dried. Rotational speeds and feed rates had an impact on feed rate per cutting edge for the major cutting edge of the drill bit which was used for correlation with DR and FF for various MC. Impact of MC on DR and FF depended on rotational speeds and feed rates of the drill bit. For feed rates per cutting edge less than 0.09 mm, DR was higher for water saturated (WS) specimens. Negligible differences between DR for various MC were found for feed rates per cutting edge between 0.09 and 0.15 mm. DR was higher at low MC for feed rates per cutting edge which were higher than 0.15 mm. FF extremely increased in conditioned (20°C/95% RH) and WS specimens at feed rates per cutting edge less than 0.1 mm.

Model for the prediction of whirling vibrations in drilling processes through semi-discretization of the drill motion equation

In this work, a model for the prediction of drilling stability against low-frequency lateral vibrations, named as whirling in the literature, is proposed. These vibrations are lateral displacements of the tool that arise at frequencies near multiples of the rotation frequency of the drill. The appearance of whirling vibrations leads to the generation of lobe-shaped holes. In order to predict whirling vibrations, the motion equation of the drill is deduced taking into account the modal characteristics of the drill and the cutting and process damping forces that act on it. In this paper, forces that arise in two different regions of the drill are considered: (1) forces on the main cutting edges and (2) forces on the chisel edge. Different force models are presented for each region that include both the regenerative effect of the vibration on the cutting area and the process damping. An oblique cutting model and an orthogonal model are employed for the calculation of cutting forces acting on the main cutting edges and on the chisel edge, respectively. The cutting force model for the main cutting edges takes into account the cutting angle (inclination angle, rake angle, and chip flow angle) variation along the main cutting edges. For the chisel edge region, where the feed speed is no longer negligible with respect to the cutting speed, the dynamic cutting angles are employed for the force model development. Concerning the process damping force model, previous works in the literature consider a constant value of the clearance angle for the calculation of the process damping coefficient. However, in this work, the variation of the normal clearance angle along the main cutting edges is considered. It is shown that, depending on the clearance face grinding parameters employed, the clearance angle can double its value along the main cutting edges. Considering the force models and through the semi-discretization of the motion equation of the drill, the appearance of low-frequency lateral vibrations is predicted regarding the drill geometry and cutting conditions such as drill rotation speed and feed. In addition, given cutting conditions at which whirling vibrations are expected to occur, the model is able to predict the vibration frequencies that are excited. The drilling model and the stability predictions are experimentally validated by means of drilling tests with different drill diameters and cutting conditions. In comparing the experimentally obtained results and the predictions obtained by the model, it is concluded that the model can reasonably predict the appearance of whirling vibrations as a function of drill geometry and cutting conditions. Generated hole shape is also analyzed through the measurement of hole roundness and bottom surface geometry. It is observed that, when drilling in the presence of whirling vibrations, holes with lobed shape and polygonal bottom surface are generated. It is also noticed that both the number of lobes and the number of sides of the polygonal bottom surface are directly related to the vibration frequencies that arise.

Study on tool wear and workpiece surface integrity following drilling of CFRP laminates with variable feed rate strategy

Drilling carbon fibre reinforced plastic (CFRP) composites is often accompanied by workpiece delamination particularly at hole exit, which is dependent to a large extent on the applied feed rate/thrust force. In this paper, a variable feed rate strategy was investigated where drill feed was decreased from a maximum of 0.3 mm/rev to 0.01 mm/rev for the final 2 mm of hole depth, in order to reduce thrust force and minimise hole exit damage but without severely impacting process productivity. A full factorial experiment involving two variable factors (CFRP lay-up configuration at two levels and primary feed rate at three levels) was performed using diamond coated carbide tools. All tests achieved the 384 drilled hole criterion with tool flank wear ranging from 114 to 193 μm, chipping/delamination of the coating and abrasion were the principal tool wear modes. Delamination factor values at hole entry generally increased with primary feed rate and number of holes drilled by up to ~23%, with limited difference in exit delamination factor between the first and last holes drilled (maximum of 0.04). The reduced feed rate regime immediately prior to hole exit led to lower surface roughness by up to ~6.46 μm Ra compared with the entry location together with reduced fibre pull out and cavities compared to the rest of the hole when drilling with a new tool. Surface quality was however less apparent with increased numbers of holes drilled and tool wear.

Comparison of the Effect of Process Fluid Using the Test by Drilling a Constant Feed Force

New types of process fluids is very broad. Drilling with constant feed force represents the experiment that follows different properties and effects in machining. The main aim of this scientific paper is to assess the speed of drilling holes by the drilling technology-constant feed force- with the drilling cutting tools made of uncoated high speed steel. Eleven different process fluids were compared used the during the experiment. There were compared eleven different process fluids. In the context of the thesis more process fluids from global suppliers have been tested. In the process of experiments there were used twist drills of high speed steel type HSS, CSN 221121, o 8 mm, without coating. Steel samples were 16MnCr5, according to EN 10084-94. During the experiment there was used drilling of holes by hand feed drill machine V 20 that was modified with the mechanical switch and there was also stopwatch. Testing of process fluids in chip machining has been going on at the Department of machining and assembly of the Technical University of Liberec for many years.

Effect of drill speed and feed mechanisms on in-row seed spacing accuracy of red beet

Effect of drill speed and feed mechanisms on in-row seed spacing accuracy of red beet

Multi-objective optimisation during drilling of CFRP composites: a PCA-fuzzy Taguchi integrated approach

Drilling of carbon fibre reinforced plastics (CFRPs) is indeed very complicated due to the high structural stiffness of the composite as a whole and the low thermal conductivity of plastic matrix. During the drilling operation, the tool comes across matrix and reinforcement alternately which results in the destruction of fibre continuity with the generation of large stress concentration in the material and delamination at the hole during entry as well as exit. Hence, appropriate selection of drilling process parameters is indeed necessary for achieving efficient machining performance on drilling of CFRP composites. In order to achieve satisfactory product quality characteristics as well as excellent machining performance, the optimisation of machining parameters like drill bit diameter, spindle speed, and feed rate are deemed compulsory. The objective of this paper is to highlight the effect of aforesaid process parameters on thrust force, torque, surface roughness, entry delamination factor and exit delamination factor in the drilling of CFRP composites. The optimal setting of the controllable process parameters has been determined through experiments planned and conducted using the Taguchi's philosophy. The application of principal component analysis (PCA) combined with fuzzy inference system (FIS) and finally Taguchi's optimisation methodology in assessing of optimal parameter setting has been discussed in this article.

Delamination study on newly formulated Ni-P coated glass fibre/nanowire - reinforced polymer composite using Grey relational analysis

Hybrid polymer composite materials are nowadays used as an economically alternative to conventional materials because of their unique engineering properties. Delamination is the major criteria to be considered during the drilling of the polymer composites. In the present work, Grey relational analysis is effectively used for optimising the machining parameters such as spindle speed, feed rate and diameter of the drill with respect to the delamination in the inlet and exit of the drilled hole of Ni-P - GF/Al2O3 nanowire reinforced hybrid composite. Optimal drilling parameters are obtained by the Grey relational grade for multi-performance characteristics, using Taguchi's L25, five-level orthogonal array. From the analysis, it is clear that the drill diameter is the most influential factor followed by the feed rate and the spindle speed. Experimental results indicate that the inlet and exit delamination can be reduced at the optimal drilling conditions of minimum feed rate (30 mm/min), drill diameter (4 mm) and maximum spindle speed (2,700 rpm).

Controlling Process Factors to Optimize Surface Quality in Drilling of GFRP Composites by Integrating DoE, ANOVA and RSM Techniques

Polymer Matrix Composites are the preferred materials now a days and are used in all the fields of engineering because of its encouraging properties over traditional materials. Glass Fiber Reinforced Polymers (GFRP) is the materials that are used in the manufacturing of household appliances up to aircraft and automobile components. Drilling operation is the common machining operation used to make holes for the fasteners in the mechanical part assembly operations. The surface quality of the hole depends upon the drill machining conditions. The drill hole quality gets degraded because of inefficiency or wear of the drill tools to make holes that are dimensionally accurate and are reliable. The tool wear takes place due to improper machining conditions and wrong working procedures. The tool wear disturbs the structural stability of the composite laminates and virtually, the quality of drilled holes. The poor quality of drilled holes affects the proper assembling of the parts and the operational performance of the final product. The objective of this research work is to control the drill process factors through a systematic approach and to analyze their significance on the quality of machined surface while drilling GFRP composite laminates using High Speed Steel (HSS) twist drills. Optimized numbers of experiments were planned and executed using Design of Experiments (DoE). Full Factorial Design (FFD) of experiments was carried out to collect surface roughness data. A statistical model was established by applying Response Surface Methodology (RSM) technique, to calculate the impact of process parameters on the hole surface quality. The capability of the model is checked using Analysis Of Variance (ANOVA). The outcomes of ANOVA indicated that the most significant factor which influences the surface quality is the drill diameter followed by drill feed rate and drill spindle speed.