Twist Drill Research Articles

A modified tool design for the drilling of high-performance aerospace materials

High-performance Ni- and Ti-based materials are generally difficult to machine. Drilling in particular is highly demanding for the applied tools due to challenging thermal stress. This paper describes a novel modification for twist drills which significantly improves the cooling and lubrication of the main and secondary cutting edges and leads to an enhancement in process productivity. Within the scope of this work, the achievable improvements with regard to wear progress, cutting edge temperature and cutting fluid flow when machining Inconel 718 are analysed. The solution developed could also prove its efficiency in the machining of titanium-based alloy Ti6Al4V.

Prediction of tool wear in CFRP drilling based on neural network with multicharacteristics and multisignal sources

Carbon fiber-reinforced polymer (CFRP) drilling is a typical process in the aircraft industry. Because the components of CFRP are different and uneven, it is difficult to extract tool wear characteristics from the machining signals, which are composed of the processing characteristics of various materials and the tool state characteristics. The aim of this work is to present a new comprehensive approach based on multicharacteristics and multisignal sources to predict the tool wear state during CFRP drilling through a combination of a backpropagation (BP) artificial neural network (ANN) model and an efficient automatic system depending on the sliding window algorithm. It was verified that the peak factor and Kurtosis coefficient of different signals and the energy value of the d5 layer of the thrust force signal and the d3 layer of the vibration signal after wavelet decomposition were related to tool wear. Among them, the energy value of the d3 layer of the vibration signal was selected as the wear indicator and was able to describe the state of the tool during the CFRP drilling process regardless of the drilling conditions and individual tool differences. A confirmatory drilling experiment using 6-mm-diameter polycrystalline diamond twist drilling under different processing parameters was conducted to verify the ANN model based on multicharacteristics and multisignal sources. A lower feed speed and a higher cutting speed were both highly correlated with the VB value of flank wear. Drill wear accelerated because of the occurrence of adhesive wear when the number of drilled holes reached around 90. The accuracy of the neural network model is 80–87% when using the value of only one characteristic but clearly increases based on multicharacteristics and multisignal sources in real time, indicating that the BP ANN model has higher accuracy in predicting the tool state in CFRP drilling through the sensor signal fusion method.

IMPROVEMENT OF TECHNOLOGICAL PROCESS OF DRILLING THIN SHEET STEELS

This article considers the technological process of drilling holes in sheet metal. The existing typical technological process, with detailed analysis, provides grounds for substantiating the idea of an innovative solution. There is a connection between the improvement of economic indicators of this technological operation with the change of geometric parameters of the tool. The comparison of existing technological processes, operations, and transitions of production of round openings with the use of spiral drills is given. The traditional technique involves a clear sequence of the technological process with the use of tools for marking, kerning, and sequential use of screw drills of different diameters. Therefore, after the previous operation of marking the center of the two holes, perform the operation of kerning. The core (recess in the metal) prevents the deviation of the small diameter screw drill from the marking lines. After the above steps, the traditional technological process involves drilling a small diameter hole in order to direct the main tool in the right direction. To make the main hole perform special sharpening of the working part of the twist drill so that the diameter of the Central part of the tool is equal to the diameter of the first guide hole to avoid further displacement of the main hole and the next operation is to drill the hole to the desired diameter. As a result, the article raises the topic, given the widespread use of sheet metal, including in the agricultural sector, the feasibility of using an innovative idea to improve the technological process associated with the processing of sheet material, namely thin metal sheets. It is worth noting that for example, we consider a material that is characterized by its versatility, namely steel Ст 3. Despite the numerous sources devoted to the study of improving the drilling process, there are a number of issues, including the extension of this direction surfaces with a covering and without it, various thicknesses within the thin-walled hire. The most significant result of the improved technological process of drilling will be used in the system of efficient maintenance of agricultural machinery.

Experimental analysis and parametric optimization of drilling process for ferrous clay composite using GRA-PCA approach

The use of materials mixture with non-metallic ingredients composed by powder metallurgy (PM) are getting increased attention in many industries. The newly developed composite material is mainly applied to the structural parts in the many industries. PM parts machining is still a challenge and known as difficult-to-cut metals for manufacturers because of the many factors mainly porosity, Nano particles and complex microstructure. In this work, the mechanical properties like density and porosity along with the machinability in drilling of a newly developed sintered powder metallurgy (P/M) components having Nano-particles of bentonite clay as machinability enhancer is evaluated by a standard twist drill. The impact of this paper aims to reveal the key cutting phenomena i.e. generation of thrust forces, quality of surface roughness, and new insight into the machining mechanism of sintered material. The parameters involved in the machinability study are as speed, feed rate and Nano-particles of bentonite clay for controlling the parametric variables on the response parameters. The speed has the major (95%) effect on the thrust force where the clay percentage has the major (84%) effect on the surface roughness. The less thrust force and low surface roughness have been achieved at 5% clay with 910 rpm and 1% clay with 2265 rpm, respectively. Further, the hybrid grey relational analysis along with principal component analysis (GRA-PCA) has been carried out to find the optimum condition. The less thrust force (Ft) and low surface roughness (Ra) has been found at 1% clay and 910 rpm. The confirmation of optimal process parameters has been made with overall evaluation criteria (OEC) and found the same optimum condition. The X-ray diffraction despises homogeneous mixture of clay in ferrous clay composite. The SEM analysis exposed the presence of clay particles and plastically deformed area during drilling of ferrous clay composite. Thus, this analysis show that the 1% of Nano-particles of bentonite clay is helpful as porosity fillers or machinability enhancer at low speed and within acceptable mechanical properties.

Robotic Navigated Laser Craniotomy for Depth Electrode Implantation in Epilepsy Surgery: A Cadaver Lab Study.

Depth electrode implantation for invasive monitoring in epilepsy surgery has become a standard procedure. We describe a new frameless stereotactic intervention using robot-guided laser beam for making precise bone channels for depth electrode placement. A laboratory investigation on a head cadaver specimen was performed using a CT scan planning of depth electrodes in various positions. Precise bone channels were made by a navigated robot-driven laser beam (erbium:yttrium aluminum garnet [Er:YAG], 2.94-μm wavelength,) instead of twist drill holes. Entry point and target point precision was calculated using postimplantation CT scans and comparison to the preoperative trajectory plan. Frontal, parietal, and occipital bone channels for bolt implantation were made. The occipital bone channel had an angulation of more than 60 degrees to the surface. Bolts and depth electrodes were implanted solely guided by the trajectory given by the precise bone channels. The mean depth electrode length was 45.5 mm. Entry point deviation was 0.73 mm (±0.66 mm SD) and target point deviation was 2.0 mm (±0.64 mm SD). Bone channel laser time was ∼30 seconds per channel. Altogether, the implantation time was ∼10 to 15 minutes per electrode. Navigated robot-assisted laser for making precise bone channels for depth electrode implantation in epilepsy surgery is a promising new, exact and straightforward implantation technique and may have many advantages over twist drill hole implantation.

The effect of twist drill angle and spindle speed on surface roughness in S45C steel drilling process

The purpose of this research is to determine the effect of twist drill angle variations and spindle rotational speed on the surface roughness of S45C steel in the drilling process. The method used in this research is the experimental method. The independent variables used in this study are variations in twist drill angle (118°, 122°, 125°) and spindle rotational speed variations (1036 rpm, 1340 rpm, 1630 rpm). The dependent variable used is the result of surface roughness in S45C steel. While the control variable used is a feed rate of 0.18 mm/round. The results showed the highest surface roughness was obtained at 125° twist drill angle variation and spindle rotational speed of 1630 rpm with a roughness value of 8.590 µm, while the lowest surface roughness value was obtained at 118° twist drill angle variation and spindle rotational speed of 1036 rpm with a roughness value of 2.898 µm. This research can be developed to find standards from other aspects that affect the results of the drilling process.

Burr-Hole Evacuation of Chronic Subdural Haematoma: A Comparative Study between Evacuation With and Without Drainage

Abstract Background: Chronic Subdural Haematomas (CSDH) are relatively common in the geriatric age group. There are several alternatives for surgical management: Burr-hole evacuation, twist drill craniostomy and craniotomy. The widely performed procedure is burr hole evacuation with drainage. Aim of Study: Evaluation of the surgical treatment of chronic subdural haematomas, we studied two surgical options of CSDH: Burr-hole evacuation with and without drainage. Material and Methods: In this retrospective study, we analyzed patients with chronic subdural haematomas subjected to surgery in our institute. A total of 72 patients were studied: 38 underwent burr-hole evacuation and irrigation with post-operative drainage (Group D) and 30 were operated without drainage (Group ND). Results: There was no case of recurrence in the 6-month post-operative period. The average period of hospitalization, the number of post-operative complications, the incidence of rebleeding and the amount of the expansion of the cerebral cortex did not differ between the two groups. Conclusion: The vital step of CSDH surgery is meticulous irrigation during the operation. To insert a drain or not, is not of great value.

Investigation of Damage Reduction When Dry-Drilling Aramid Fiber-Reinforced Plastics Based on a Three-Point Step Drill.

Aramid fiber-reinforced plastic (AFRP) is widely used in bullet-proof and armor structures, and is difficult to drill because of the high-toughness aramid fibers with ductile fracturing—differently from carbon fiber. Therefore, drilling quality cannot be ensured by the drilling used for carbon fiber-reinforced plastic, and frequently, delamination and burrs occur in the drilling process. This article first established a two-dimensional cutting model for analyzing the fiber deformation and material interface cracking. According to the model, reducing the thrust force and the radial force of the edge on the fibers is an effective way to reduce the fiber deformation, and a three-point step drill is proposed further. Comparative experiments were carried out among twist drilling, candle core drilling and three-point step drilling under three drilling parameters. The results show that the three-point step drill changed the traditional cutting behavior on the drill-exit material into a compound process. Finally, the AFRP was cut effectively with the novel drill with a small thrust force, and the delamination and “burrs area” were reduced through different drilling parameters. In summary, the three-point step drill can drill the AFRP without delamination and burrs with 0.02 mm/rev, which provides a new solution of cost-effective production for AFRP manufacturers.

Geometric Optimization of Drills Used to Repair Holes in Magnesium Aeronautical Components

Magnesium alloys are used in the aeronautical sector due to their excellent strength/weight ratios, motivated by the reduction of weight that their use entails. In this sector, drilling is one of the most common operations, if not the most, due to the large number of holes that are used in joining processes, mainly by riveting. The appearance of cracks is a risk to the structural safety of the components, such that it is necessary to regularly check them for maintenance and/or repair tasks. The present study tries to determine the optimization of the characteristics of the twist drills, which are re-sharpened successively to restore the cutting edge after use, as well as the operating parameters in machining. For this purpose, a full factorial experimental design was established, analyzing through the analysis of the variance (ANOVA) the response variables. Surface integrity was considered to carry out a global vision of the quality obtained, covering as response variables the surface roughness, the size of the burrs and the modification of the hardness produced, in addition to a topological characterization by optical means of machined surfaces. The main conclusion is that it is possible that the geometric optimization of the tools and the operating parameters considered in this study in drilling processes allow them to be performed, while maintaining quality and environmental requirements, and at the same time, maximize the productivity of operations.

Performance assessment of vegetable oil-based minimum quantity lubrication (MQL) in drilling

Metalworking fluids are widely used to increase productivity and quality of metal cutting. However, these metalworking fluids possesses the problems in terms of the effect on environment and health of the worker. Hence, various approaches to provide cooling and lubrication are explored such as mist cooling, high-pressure cooling, minimum quantity lubrication (MQL), nano fluids, solid lubricants, etc. In this regards, the present work exhibits the performance evaluation of vegetable-based minimum quantity lubrication (MQL) in drilling of aluminium alloy. This drilling tests have been performed in different cutting environments such as Dry, flood cooling, MQL with castor oil, MQL with sunflower oil with uncoated HSS twist drill. The effect of various drilling parameters have been analysed by measuring surface roughness, axial thrust, and torque produced. The comparison of results indicates effectiveness of the vegetable-based MQL in terms improved surface finish and reduction in axial thrust and torque during drilling.

Ultrasonic-assisted drilling of nickel-based super alloy in conel 601: An experimental study

In this study, a comparison between ultrasonic-assisted drilling (UAD) and conventional drilling (CD) is presented under different feed rates using thrust force, torque, and hole geometrical errors as output responses. The experiments were done on plates of Inconel 601 (nickel-based superalloy), which is classified as a difficult-to-cut alloy due to its high Nickel content (60%), high hardness (43 HRC), and low thermal conductivity. The experiments were performed using DMG Mori Ultrasonic 20 linear, which is equipped with ultrasonic tool holderoscillating at 20 kHz with 7 μm amplitude. A coated carbide single margin twist drill had been used in the experiments. Full factorial design of experiments approach was employed, and the results had been statistically analyzed to find the most significant factor affecting the process responses. The results showed that the ultrasonic assistance had reduced the thrust force, and torque compared to conventional drilling (CD). Also, a reduction in holecylindricity error was detectedduring UAD, whichimprovesthe hole quality. In case of UAD, twist drills did not suffer from a physical wear, however notch wear was observed in CD drills. Chip morphology was also studied. Short segmented chips were obtained when using UAD which improved chip evacuation and reduced the chance of chip jamming in the drill flutes.

Study the Impact of Drilling Process Parameters on Natural Fiber Reinforced Herringbone Epoxy Composites

Common fiber composite overlays are attractive for a few applications, (for example, aviation and flying machine auxiliary parts) because of their predominant properties and bio-degradable. Typically, mechanical drilling process parameters are significant effect final machining process outcomes. It covers drilling performance like convectional drilling, grinding, vibration-influence twist drilling, and rapid boring, drilling apparatus geometry and materials, drilling actuated delamination and its smothering methodologies, thrust power, and wear rate. This paper aimed to address the effect and ranking of process parameters on trust force, torque, and delamination at both entry and exit of the hole sisal fabric herringbone reinforced epoxy composites. The herringbone woven sisal fabric reinforced epoxy composite is fabricated using conventional compression molding technique. The result shows that at higher speed and feed rate delamination at both entrance and exit, thrust force, and toque decreases. Optimum drill diameter found from 6 to 10 mm to obtain minimum responses. As four output parameters are deciding quality of drilled hole, further grey regression analysis is used to study the ranking of output responses. Form grey regression analysis it is found that for 2700 rpm spindle speed, 60 mm/min feed and 8 mm diameter exhibit minimum effort.

Effect of cooling method on small diameter blind-hole drilling of new β-type dental Ti-Zr-Nb alloy

Abstract A β-type titanium-zirconium-niobium alloy (Ti-Zr-Nb alloy) is an ideal substitute for the currently used dental implants with the advantages of high specific strength, low elastic modulus, good biocompatibility, non-toxicity and corrosion resistance. However, its low elastic modulus and sticking characteristics results in poor heat dissipation and severe wear and tear making it difficult to drill. In this paper, a 2 mm diameter solid carbide twist drill was used to conduct small hole drilling experiments on a new, self-smelted, low-modulus β-type Ti-Zr-Nb alloy. The effects of the drilling parameters and five cooling methods (dry, flooded, cryogenic, minimum quantity lubrication (MQL) and cryogenic-minimum quantity lubrication (CMQL)) on thrust force, surface quality, microhardness and tool wear were studied. Results showed the minimum thrust force was obtained during the drilling process with the MQL cooling method and the β-type Ti-Zr-Nb alloy which did not exhibit low temperature brittleness was not suitable for processing at cryogenic cooling because the low temperature changed the yield strength and the stress for plastic deformation of the material's surface. The main wear mechanism of the β-type Ti-Zr-Nr alloy was adhesion, and the material properties and crystal structure of Ti-Zr-Nb alloy were the physical foundations that produced the adhesion phenomenon. However, cooling conditions also had an important effect on wear. Oxidative wear tended to occur when there was little or no coolant, and fatigue wear was observed with the signal of cracking, pitting and layer delamination using the cooling method of CMQL. The sawtooth angle ϕ of chips was larger under the dry drilling and cryogenic cooling methods, than that of the other three cooling methods. The MQL cooling method is recommended to effectively improve the tool durability.

Evaluation of the primary stability in dental implants placed in low density bone with a new drilling technique, Osseodensification: an in vitro study.

Background Primary stability is an important key determinant of implant osseointegration. We investigated approaches to improve primary implant stability using a new drilling technique termed osseodensification (OD), which was compared with the conventional under-drilling (UD) method utilized for low-density bones. Material and Methods We placed 55 conical internal connection implants in each group, in 30 low-density sections of pig tibia. The implants were placed using twist drill bits in both groups; groups Under Drilling (UD) and Osseodensification (OD) included bone sections subjected to conventional UD and OD drilling, respectively. Before placing the implants, we randomized the bone sections that were to receive these implants to avoid sample bias. We evaluated various primary stability parameters, such as implant insertion torque and resonance frequency analysis (RFA) measurements. Results The results showed that compared with implants placed using the UD technique, those placed using the OD technique were associated with significantly higher primary stability. The mean insertion torque of the implants was 8.87±6.17 Ncm in group 1 (UD) and 21.72±17.14 Ncm in group 2 (OD). The mean RFA was 65.16±7.45 ISQ in group 1 (UD) and 69.75±6.79 ISQ in group 2 (OD). Conclusions The implant insertion torque and RFA values were significantly higher in OD group than in UD. Therefore, compared with UD, OD improves primary stability in low-density bones (based on torque and RFA measurements). Key words:Osseodensification, primary stability, low density bone, RFA.

A simple and effective modified technique of twist drill craniostomy for bedside drainage and irrigation of chronic subdural hematoma: Technical and clinical study

ObjectiveChronic subdural hematoma (CSDH) is an important health problem observed mostly in elderly population. Here, we aimed to describe and validate a simple modified technique of twist-drill craniostomy (TDC) using easily accessible tools for effective and safe bedside CSDH drainage. MethodsA detailed description of the new modified TDC technique which allows for sequential drainage and irrigation under physiological conditions is provided. Clinical and radiological characteristics as well as surgical results of the patients undergoing this procedure are also presented. ResultsA total of 55 patients (30 M, 25 F) underwent this modified TDC. Mean age was 61.7 ± 12.3 years. Medical comorbidities were common (76.4 %). Subdural hematoma was mostly unilateral (83.6 %). Maximum width of hematoma was 21 ± 4 mm on average (range: 9−38 mm). In total, patients underwent 1.6 ± 0.9 subdural tappings on average (median: 1, range: 1−5). Repeat tappings were performed in 43.6 % of the patients. No mortality, serious morbidity or infectious complications were noted. Pneumocephalus was either absent or minimal in most cases (96.4 %). Mean length of hospital stay was 4.9 ± 4.0 days (median: 3; range: 2−20 days). The clinical outcomes were favorable in 92.7 % of the patients (no craniotomy required and no symptomatic recurrence detected). ConclusionThis modified technique of TDC utilizes easily available tools, yields satisfactory radiological and clinical results, allows repeated tappings even in outpatient settings and can thus be readily applied in every neurosurgical unit across the world. It can be an effective alternative to existing procedures for patients with multiple co-morbidities and/or high anesthesia risk, in emergency conditions and busy neurosurgical centers.

Study on Deep Hole Drilling Process and Cutting Performance

In deep hole machining, drilling parameters for twist drills have an important impact on tool life and economic efficiency. In order to explore the influence of drilling parameters on twist drills, this paper established a drilling model for twist drill 45 steel, orthogonal experiments were designed. AdvantEdge FEM finite element software was used to simulate the drilling force, torque and drilling temperature. The drilling force, torque and drilling temperature were analyzed by using the finite element simulation value as the orthogonal experimental value. In order to ensure that the simulation results have certain reference value, the drilling experiment was carried out in order to ensure the simulation results have reference value. Finally, the optimal combination of drilling parameters was obtained.

Tips and Pearls in Chronic Subdural Hematoma

Background and Aim: One of the most prevalent neurosurgery conditions is Chronic Subdural Hematoma (CSDH). Among neurosurgeons, there are various CSDH treatment approaches. Methods and Materials/Patients: This is a narrative review examining the various aspects of the CSDH. To provide up-to-date information on CSDH, we concisely reviewed the related articles. All of the relevant articles retrieved from Google Scholar, PubMed, and Medline were reviewed and critically analyzed. We searched for keywords including chronic subdural hematoma, burr hole craniotomy versus craniostomy, middle meningeal artery embolization, conservative therapy versus surgical therapy in CSDH, and recurrence of CSDH in published articles from 1960-2020. Results: CSDH may present with various clinical presentations. Medical symptoms range from general and moderate symptoms (such as headache, tiredness) to severe symptoms (e.g. hemiparesis, coma). A definite trauma history may be obtained in most cases. Contrast-enhanced CT or MRI may help diagnosis. The treatment choice for uncomplicated CSDH is Burr-Hole Craniotomy (BHC). The use of drainage to decrease recurrence rates has been shown to have limited outcomes in most recent studies. Craniotomy is also used for treatment. Only asymptomatic or high-risk operative patients are subjected to non-surgical management. Conclusion: Management of CSDH is still contentious. It is widely agreed that if neurological signs and radiological observations are present, CSDH should be evacuated. Burr-hole craniotomy appears to be the preferred surgical technique because, in most patients, it gives the best treatment outcomes. Several issues are still uncertain, including the proper surgical technique [Burr-hole craniotomy versus Twist Drill Craniostomy (TDC) and craniotomy], the advantage of 2 perforated holes over one, the location of drainage, the impact of irrigation of the hematoma, and the duration of post-operative immobilization.

Cryogenic Drilling of AZ31 Magnesium Syntactic Foams.

Machined surface quality and integrity affect the corrosion performance of AZ31 magnesium composites. These novel materials are preferred for temporary orthopedic and vascular implants. In this paper, the drilling performance of AZ31-magnesium reinforced with hollow alumina microsphere syntactic foam under LN2 cryogenic, dry, and Almag® Oil is presented. Cutting tests were conducted using TiAlN physical vapor deposition (PVD) coated multilayer carbide and K10 uncoated carbide twist drills. AZ31 magnesium matrices were reinforced with hollow alumina ceramic microspheres with varying volume fractions (5%, 10%, 15%) and average bubble sizes. Experimental results showed that the drilling thrust forces increased by 250% with increasing feed rate (0.05 to 0.6 mm/tooth) and 46% with the increasing volume fraction of alumina microspheres (5% to 15%). Cryogenic machining generated 45% higher thrust forces compared to dry and wet machining. The higher the volume fraction and the finer the average size of hollow microspheres, the higher were the thrust forces. Cryogenic machining (0.42 µm) produced a 75% improvement in surface roughness (Ra) values compared to wet machining (1.84 µm) with minimal subsurface machining-induced defects. Surface quality deteriorated by 129% with an increasing volume fraction of alumina microspheres (0.61 µm to 1.4 µm). Burr height reduction of 53% was achieved with cryogenic machining (60 µm) compared to dry machining (130 µm). Overall, compared to dry and wet machining methods, cryogenic drilling can be employed for the machining of AZ31 magnesium syntactic foams to achieve good surface quality and integrity.

Optimization of Cutting Process Parameters in Inclined Drilling of Inconel 718 Using Finite Element Method and Taguchi Analysis.

Nickel-based superalloys are famous in the demanding applications. Inconel 718 is one of the most commonly used nickel-based superalloys due to its extraordinary inherent properties. Inconel 718 is a suitable material for high temperature applications due to the properties such as anti-oxidization, high hot hardness, high creep, and fatigue strength. Drilling operation is one of the most widely used manufacturing operations in almost all industrial sectors. However, drilling operation is very complex in nature due to the presence of intricate geometry of the drill bit. In conventional drilling, cutting is performed by the combined action of the chisel edge and the two or more cutting lips. In depth analysis of the cutting process shows that chisel edge starts with an indentation at the center of the twist drill. Then away from the center, chisel edge performs orthogonal cutting with negative rake angle. Whereas, cutting action at the cutting lip is oblique in nature, and force analysis involves the use of element formulation due to involvement of radius. It is rarely found in the literature where drilling operation at different inclination angles is conducted and analyzed. The presented study numerically investigates the cutting performance of drilling operation, when operated at different inclination angles. The study revealed cutting force variation at different inclination angles due to the different tool workpiece engagement for each inclination. The magnitude of thrust force increased when inclination angle is changed from 30° to 60°. It can be linked with the higher chip load initially in this case as compared to the 30° inclination angle. The cutting temperature was affected by spindle speed (53.7%), followed by feed rate (33.31%) and inclination angle (3.44%).

FURAÇÃO DE MATERIAL SANDUÍCHE EMPREGANDO BROCAS COM GEOMETRIAS DIFERENTES: CONSTRUÇÃO DE MODELO MATEMÁTICO PARA PREVISÃO DA FORÇA DE AVANÇO

Os materiais sanduíche são assim denominados pois combinam as propriedades de dois diferentes materiais, adquirindo uma estrutura com um núcleo e duas faces externas. Uma das formas de processar este material é por meio da usinagem, mais especificamente em operações de furação, que foi o foco dessa pesquisa. A redução dos esforços de corte é desejada durante a operação de furação, impactando melhor qualidade dos furos devido a redução das vibrações no sistema. Também pode aumentar a vida útil das ferramentas, eliminando custos devido ao maior tempo para substituição das mesmas. Partindo deste princípio, esta pesquisa aliou conhecimentos estatísticos aplicados à engenharia, a fim de construir modelos matemáticos para prever o comportamento da força de avanço na furação de material sanduíche empregando brocas com geometrias diferentes, denominadas Brad & Spur, helicoidal com duas arestas e helicoidal com três arestas e. O objetivo foi elaborar equações de regressão linear múltiplas para identificar a influência da velocidade de corte e do avanço sobre a força de avanço para cada uma das brocas estudadas. Além disso, foi investigado se a geometria das brocas impactou em um comportamento que pudesse ser modelado por meio de equações matemáticas, com um determinado grau de confiança aceitável.