Cut Thickness Research Articles

Effect of Sawing Variation on Hardwood Lumber Recovery—Part I: Volume

Abstract Sawing variation (SV), the degree of deviation from a specified target lumber size, is an unavoidable component of the sawing process. SV is influenced by several factors such as machine, material, set works, feed works, and cutting parameters. To account for these factors resulting in deviations from the desired target size, the target thickness of the lumber cut must be increased such that only a minimal number of boards is less than target thickness. Thus, the greater the amount of SV, the larger the target thickness must be such that a minimal quantity of undersized lumber is produced. Hence, with larger amounts of SV come greater waste and decreased opportunities for optimizing lumber recovery. However, the decrease in material loss due to a reduction in SV may not necessarily translate into a statistically significant increase in lumber product recovery by volume. This study explored the effect of varying degrees of SV on lumber recovery by volume for a range of hardwood log diameters using the US Forest Service's LOg ReCovery Analysis Tool sawmill simulation software. A minimal average recovery improvement of 3 percent due to reduced SV was observed across all kerf thicknesses, equating to a production value improvement of $336,000 for an 8 million board feet mill. Results indicate that the recovery gains realized by volume depend upon the log diameters sawn, the lumber target thickness, and the change (reduction) in SV.

POST MENOPAUSAL BLEEDING PATTERNS IN PREDICTION OF ENDOMETRIAL CARCINOMA

Objective: To determine the demographic profile, patterns of bleeding and histopathological patterns of endometrial biopsy in women presenting with postmenopausal bleeding. Study Design: Descriptive cross-sectional study. Place and Duration of Study: Department of Obstetrics and Gynaecology, CAIMS, Karimnagar from October 2020 to April 2022. Material and Methods: This descriptive cross-sectional study included women of any parity and age >45 years who had spontaneous cessation of menstruation for the last one year and who presented with abnormal uterine bleeding. Premenopausal women, drug or irradiation induced, or iatrogenic menopause cases were excluded. All patients were admitted, transvaginal ultrasound done (cut off endometrial thickness >4mm) and subjected to dilatation and curettage under anesthesia and endometrial biopsies obtained. Samples were sent for histopathology and followed. Results: A total of 70 women were included. Commonest age group was 61-70 years, and was seen in 38 (54.3%) women, followed by the 52-60 years age group where 18 (25.7%) subjects were observed. Mean age was 62 ± 2.54 years. Twenty-four (35%) women were hypertensive while Type 2 Diabetes Mellitus (T2DM) was seen in 14 (20%). forty (57%) women complained of streaks of blood on the sanitary pad, and in 56 (80%) (P=0.032) there were recurrent episodes. Forty-eight (68.57%) women were multiparous. Atrophic endometrium was the most common benign histopathological pattern, seen in 18 (26%) followed by 16 (23%) chronic endometritis. Endometrial carcinoma was seen in 16 (23%). (p=0.041) Conclusion: Postmenopausal bleeding is an alarming symptom and should be thoroughly investigated with transvaginal ultrasound followed by endometrial biopsy for timely diagnosis and treatment.

Improving the machining performance in single-point diamond turning of curved Zerodur optics by using straight-nosed cutting tools

The machining performance and mechanisms of straight-nosed cutting tools in the single-point diamond turning (SPDT) of curved Zerodur optics are analysed and experimentally investigated. Analyses into the SPDT processes of convex spherical Zerodur samples have shown that using straight-nosed cutting tools can significantly reduce the cut thickness for facilitating the ductile-mode material removal while increasing the width of cut compared with the conventional round-nosed cutting tools. Calculations have also shown that lower cutting force intensities would be acting on the straight cutting edges than the round ones, which can in turn contribute to decreasing the heat flux density into the cutting tool, and is thus expected to reduce the thermal-induced cutting tool wear. To verify these, SPDT tests of spherical Zerodur samples were carried out, where a reduction of the machined surface roughness from Ra 173 nm to 15 nm was achieved by using the straight-nosed cutting tools, and a 96% area ratio of ductile-mode cutting was obtainable with very slight damage marks left on the machined surface. It has been further found that the straight-nosed cutting tools suffered less flank wear, as well as less bluntness and recession of the cutting edge. The mean cutting and thrust forces acting on per unit length of the cutting edge were found to be reduced, which agrees well with the prior analytical results, and is believed as evidence for the reduction of cutting power required for each unit cutting edge area for enhancing the resistance to cutting tool wear.

Accuracy of the Tibial Component Alignment by Extramedullary System Using Simple Radiographic References in Total Knee Arthroplasty.

Background and Objectives: The tibial component alignment is an important issue for the longevity of total knee arthroplasty (TKA). The purpose of our study was to investigate the usefulness of proximal tibial references determined by pre-operative radiography and intraoperative C-arm-guided hip and ankle center marking for the extramedullary guided tibial cut in mild (<10°) and severe (≥10°) varus knee TKA. Materials and Methods: A total of 150 consecutive patients (220 cases) who underwent total knee arthroplasty who were recruited from July 2011 to April 2017 were reviewed retrospectively. Before surgery, the proximal tibial reference point and medio-lateral cut thickness difference were identified. Then, hip and ankle centers were checked using a C-arm intensifier intraoperatively. The hip–knee–ankle (HKA) alignment and medial proximal tibial angle (MPTA) were assessed pre-operatively and post-operatively. More than 3° varus or valgus of HKA alignment or tibial component angle was defined as an outlier. Results: Mean follow-up duration was 26.9 months. Among 220 cases, 111 cases are classified as mild varus group and 109 cases are classified as severe varus group. The HKA alignment is significantly improved (p < 0.001). The average tibial component angle after surgery is 90.1°. A total of 21 cases (9.5%) and 3 cases (1.4%) are classified as outliers of HKA alignment and MPTA, respectively. Among MPTA outliers, one case is in the mild varus group and two cases are in the in severe varus group (p = 0.62). Conclusion: Measurement of proximal tibial radiographic references and checking the C-arm-guided intraoperative hip and ankle center could be helpful to obtain the favorable coronal position of the tibial component in the extramedullary guided tibial cut.

Investigation of thermal behaviour of structural steel S235N under laser cutting process: Experimental, analytical, and numerical studies

Laser cutting represents an appealing solution for high machining speed and precision in steel constructions. To control the efficiency of laser cutting, the effects of laser heating must be understood; and to investigate thermal effects on a steel workpiece, a methodological approach for analytical modeling of laser cutting heat source is proposed herein. The proposed model takes into account laser source geometry variation along the cut edge thickness. Given the complexity of the analyzed process, there is no accurate mathematical formulation capable of modelling both heat flux and temperature distribution. Therefore, to model heat flux with an accurate temperature distribution field and both calibrate and validate solid phases of a cut specimen, the paper proposes a modified heat source based on a Gaussian distribution. The study focuses on mild structural steel S235N and relevant commonly used laser cutting parameters for structural applications. More precisely, the model allows the laser cutting process to be simulated as a function of laser beam diameter, cutting speed, laser power and element thickness. Thus, to simulate the thermal process by means of a proper heat source, a model was implemented in the FE software Abaqus. Model parameters were both calibrated and validated through experimental results provided by online monitoring of laser cutting process with a thermal camera and location of microconstituents. In particular, the temperature profiles obtained from the proposed FE model, exhibit a good agreement with experimental results. Finally, the distribution of microconstituents along the depth agrees with predicted temperature profiles.

Dynamic response of flexible viscoelastic kerf structures of freeform shapes

Kerfing which is also known as relief cutting is a technique used to create flexible freeform surfaces out of rigid planar surfaces. Due to their pleasing aesthetics, flexibility, and ability to be molded into desired freeform shapes, they have several potential applications in engineering and architecture. The flexibility and reconfigurability of kerf structures depend on several kerf parameters such as cut density, size of the unit cell, cut thickness, cut pattern, etc. This study focuses on using kerf structures to create freeform surfaces and understanding their dynamic response in terms of mode shapes, resonance frequencies, and stress wave propagation of reconfigurable large-scale kerf structures. The effect of kerf cut density and unit cell size on the unit-cell modal behaviors is first investigated using both mathematical modeling and experiments. A beam element model is used to capture deformations of kerf structures. Next, the shape reconfigurable behaviors of two kerf panels with uniform cut density and transitioning cut density are presented. The dynamic response of these two kerf panels is then examined. The analysis of large-scale kerf panels demonstrated the capability of the beam element model to capture the modal response of kerf panels. The flexibility of the kerf panels enables local and global shape reconfigurations, which can alter the dynamic response (i.e., modal response and stress wave propagation) of the kerf panels. We perform a comparative study on the effect of shape reconfiguration (local and global) on the modal response and stress propagation behavior of the kerf panel. Overall, these findings would help design kerf structures for indoor and outdoor architectures with desired performance requirements.

Varus morphology and its surgical implication in osteoarthritic knee and total knee arthroplasty

BackgroundKnee varus alignment represents a notorious cause of knee osteoarthritis. It can be caused by tibial deformity, combined tibial–femoral deformity and/or ligament imbalance. Understanding malalignment is crucial in total knee arthroplasty to restore frontal plane neutral mechanical axis. The aim of this study was to determine which factor contributes the most to varus osteoarthritic knee and its related surgical implications in performing a total knee arthroplasty.MethodsWe retrospectively evaluated 140 patients operated for total knee arthroplasty due to a varus knee. Full-leg hip to ankle preoperative X-rays were taken. Radiological parameters recorded were: mechanical axis deviation, hip–knee–ankle, anatomical–mechanical angle, medial neck shaft angle, mechanical lateral distal femoral angle (mLDFA), medial proximal tibial angle (MPTA), joint line convergence angle (JLCA), lateral proximal femoral angle, lateral distal tibial angle (LDTA), femoral bowing, and length of tibia and femur. We also determined ideals tibial and femoral cuts in mm according to mechanical alignment technique. A R2 was calculated based on the linear regression between the predicted values and the observed data.ResultsThe greatest contributor to arthritic varus (R = 0.444) was MPTA. Minor contributors were mLDFA (R = 0.076), JLCA (R = 0.1554), LDTA (R = 0.065), and femoral bowing (R = 0.049). We recorded an average of 7.6 mm in lateral tibial cut thickness to restore neutral alignment.ConclusionsThe radiological major contributor to osteoarthritic varus knee alignment is related to proximal tibia deformity. As a surgical consequence, during performing total knee arthroplasty, the majority of the correction should therefore be made on tibial cut.

Sizes of Soil Chip Cut By a Continuously Operating Planting Hole Digging Machine with an Active Tillage Unit

Abstract Planting hole digging is a minimal tillage method, which is beneficial in terms of reducing energy consumption and preventing erosion. Current popular planting hole diggers work intermittently, which results in low productivity. A continuous-operating hole digging machine with an active tillage unit can solve this issue. However, the theoretical basis for this type of digger has not yet been developed; this is also true for the issue of determining the chip thickness – one of the main technical characteristics which significantly influences energy and agrotechnical indicators of active soil tillage. This paper presents research results of determining the soil chip cut thicknesses and observing of new cutting surface under a continuous operation of hole digging machine with an active tillage unit. At the same time, impacts of factors such as the number of knives and the kinematic factor on soil chip sizes are studied. The soil chip size determination and investigation of influence of kinematic and structural parameters on it is conducted via numerical simulation using MATLAB software. The key factors include kinematic factor λf and the number of knives on one cross-section of the tiller’s rotor Z. When λf and Z increase, the maximum average thicknesses decrease gradually; and vice versa, the new specific cutting surface decreases almost linearly. The results are considered a basis for the selection of final parameters for the construction and operation of one machine to meet agronomic requirements.

OPTIMIZATION OF COLD SPLICING PARAMETERS IN CONVEYOR BELT JOINTS ON SHEAR STRENGTH USING TAGUCHI METHOD

In the manufacturing industries, the main problem of material handling process using conveyor belt. Belt that continuously work will have damage or failure, so it repair by cold splicing. The purpose of this study is to see the effect of cold splicing parameters on the shear strength of conveyor belt joints based on variations in the number of belts, bias cut and adhesive thickness. Variations in the number of ply belts used are 2 ply, 3 ply and 4 ply, variations of cut bias 0.3xB, 0.6xB and 0.9xB and variations in the thickness of the adhesive which are 1 mm, 2 mm and 3 mm. This research was conducted experimentally using the Taguchi method based on shear test data using the Universal Testing Machine. Based on ANOVA value, the number of belt ply was high contribution by 86.22% with F-value = 155.3 and bias cut was lowest contribution by 0.23%.

Accuracy of Patient-Specific Instrument for Cylindrical Axis Implementation in Kinematically Aligned Total Knee Arthroplasty.

In kinematically aligned total knee arthroplasty (KA-TKA), the cylindrical axis (CA) is very important in restoring the native joint line and kinematics of the pre-arthritic knee. This study aimed to determine the accuracy of patient-specific instrument (PSI) for restoring the CA for femoral bone resection in KA-TKA. Thirty KA-TKAs were performed using a computed tomography (CT)-based PSI system. Data from preoperative CT were reconstructed into three-dimensional (3D) models using 3D-planning software. The CA was created by connecting the centers of each virtual sphere to the medial and lateral femoral condyles using computer software. Femoral bone resection of the distal and posterior condyles was performed parallel to the sagittal planes of the CA. The thickness of the CA-referenced bone resection was determined based on the thickness necessary for the respective regions of the femoral component. The PSI was manufactured to locate the guide pin for a conventional cutting block. The accuracy of PSI for KA-TKA was evaluated as the absolute error between the preoperatively predicted thickness and the intraoperative measurements in each of the four regions, as well as the difference in error between distal-medial (DM) and posterior-medial (PM) and between distal-lateral (DL) and posterior-lateral (PL). The differences in thickness of bone cut in the DM, DL, PM, and PL were 0.79 ± 0.39 mm (range, -1.20 to 1.50), 0.70 ± 0.42 mm (range, -1.50 to 1.50), 0.80 ± 0.46 mm (range, -0.80 to 1.50), and 0.75 ± 0.47 mm (range, -2.10 to 1.40), respectively. There was no significant difference in the thickness error between DM and PM (p = 0.959) and between DL and PL (p = 0.812). In KA-TKA, PSI was effective for accurate femoral bone resection based on virtually planned thickness.

A model-based investigation of tool-chip friction during precision micro cutting of commercially pure titanium alloy

Understanding interaction between the cutting tool edge radius and the work material is essential to identify the conditions leading to superior surface finish during the micromachining process. The interaction between friction angle and effective rake angle has been investigated based on a slip-line field-based machining model from the literature. Machining forces and cut chip thickness values were obtained from orthogonal cutting tests and employed in the process model. The proposed model also allows for calculating material properties such as shear flow stress and fracture toughness. The proposed model can successfully simulate machining forces during shearing-dominated machining conditions. The results showed the importance of flank and rake face friction in micro-scale machining.

Temperature Behavior of SAW Resonators Based on LiNbO₃/Quartz and LiTaO₃/Quartz Substrates.

LiNbO3 (LN) or LiTaO3 (LT) thin plates bonded to quartz are novel types of layered substrates for temperature-compensated surface acoustic wave (TCSAW) devices. In SAW resonators with Al electrodes arranged on LT/quartz and LN/quartz substrates, improved temperature behavior due to opposite signs of temperature coefficients of frequency (TCF) in quartz substrates and LT or LN plates can be combined with high Q -factors if the quartz orientation is optimized. The quartz orientation areas that enabled high Q -factors were deduced from analyzing the quartz anisotropy and the characteristics of shear horizontally (SH) polarized waves were calculated in the optimal orientations as functions of the quartz cut angle and plate thickness. The simulation results illustrated by contour plots of the wave characteristics revealed the presence of zero lines on the plots demonstrating TCFs at resonant (TCFR) and antiresonant (TCFA) frequencies in both layered structures. The strong quartz anisotropy explained anomalous temperature behavior of SAW resonators and the existence of LT/quartz structures with TCFA = TCFR facilitating the design of SAW devices with improved thermal stability in the passband. In the LT/quartz structures, two TCFs vanished simultaneously at certain plate thickness and quartz orientation, while in the LN/quartz zero lines did not intersect but low TCF = -(10-20) ppm/°C combined with electromechanical coupling exceeding 18% were obtained numerically in some structures. The effect of inverting the propagation direction or cut angle in one of the combined materials on the wave characteristics was discussed and numerically estimated.

Preoperative varus deformity of the knee affects the intraoperative joint gap in unicompartmental knee arthroplasty

BackgroundIt is generally believed that contraction of the soft tissue structures on the medial side may occur in the knee with severe varus deformity. However, the relationship between the severity of varus deformity of the knee and the intraoperative soft tissue balance in unicompartmental knee arthroplasty (UKA) has not been well reported thus far. MethodsOne hundred and three consecutive medial UKAs were enrolled. After the femoral trial prosthesis was placed, the component gap was measured at 10° (extension) and 120° (flexion) of flexion using a UKA tensor. The pre-osteotomy gap was then calculated from the thickness of the bone cut. Paired Student’s t-test was used to compare the component gap, as well as the pre-osteotomy gap, in extension and those in flexion. The relationship between the preoperative Hip-Knee-Ankle (HKA) angle and the pre-osteotomy gap was analysed using Pearson’s correlation coefficient and simple linear regression analysis. ResultsThe component gap in extension was significantly smaller than that in flexion while the pre-osteotomy gap in extension was significantly wider than that in flexion. There was a positive correlation between the severity of varus deformation in preoperative knee and the pre-osteotomy gap in extension, while there was no correlation between the preoperative HKA angle and the pre-osteotomy gap in flexion. ConclusionsThe tension of the medial tightness does not correlate with the degree of preoperative varus deformity in UKA.

Does measuring the medial gap before bone resection in total knee arthroplasty provide optimum gap adjustment and prevent bone recutting?

Objectives:The aim of this study was to demonstrate that measuring the medial gap before bone resection during total knee arthroplasty (TKA) provides an optimum gap adjustment in varus knees.Methods:Patients were separated into two groups, Group 1 being those whose medial joint gap was measured prior to bone resection and Group 2 comprising those who underwent conventional measured resection technique without measuring. The medial joint gap was measured with a custom-made gap measuring device up to the point that the knee was corrected and aligned along its mechanical axis. Medial joint gap distances, distal medial femoral bone cut thicknesses, amounts of tibial resection calculated, gap internal distances measured after cutting, and the thicknesses of the trial inserts were recorded. A comparison was made between the groups in terms of the number of patients requiring an additional tibial bone cut and the distribution of insert thicknesses.Results:Extra tibial bone resections performed in two (5.7%) patients in Group 1 and in 10 (28.6%) patients in Group 2. In Group 1, where the medial joint gap was measured, the need for an additional bone resection was statistically less. (p=0.018). In the comparison of distribution of insert size by group, the number of patients on whom an 8 mm insert had been used was significantly greater in Group 1 (p=0.024).Conclusion:Measuring the medial joint gap prior to bone resection in total knee arthroplasty may prevent repeated bone recutting and additional bone resections. Furthermore, we can use this method to avoid the disadvantages of the measured resection technique.

High-Performance Face Milling of 42CrMo4 Steel: Influence of Entering Angle on the Measured Surface Roughness, Cutting Force and Vibration Amplitude

High feed Milling is a new milling method, which allows to apply high feed rates and increase machining efficiency. The method utilizes face cutters with a very small entering angle, of about 10°–20°. Thus, the cut layer cross-section is different than in traditional milling. In order to examine the high feed milling (HFM), experimental tests were conducted, preceded by an analysis of cutting zones when milling with an HF face cutter. The face milling tests of 42CrMo4 steel with the use of an HF cutter characterized by an entering angle, dependent on axial depth of cut ap and insert radius r values, as well as with a conventional face cutter with the entering angle of 45° were performed. The study focused on analyzing the vibration amplitude, cutting force components in the workpiece coordinate system, and surface roughness. The experimental tests proved, that when milling with constant cut layer thickness, the high feed cutter allowed to obtain twice the cutting volume in comparison with the conventional face cutter. However, higher machining efficiency resulted in an increase in cutting force components. Furthermore, the results indicate significantly higher surface roughness and higher vibration amplitudes when milling with the HF cutter.

Theoretical study on frequency spectrum characteristics of surface profiles generated in micro-end-milling process

Micro-milling is a flexible and promising fabrication process. Based on the analysis of the surface formation process in micro-end milling, the theoretical surface model was established to investigate the influence of seven identified factors, i.e., minimum cut thickness (MCT), elastic recovery, plastic side flow, radial and axial runout, tool wear (corner radius and unbalanced wear coefficient), and vibration on the frequency spectrum characteristics. The increase of MCT coefficient and plastic side flow height could increase the amplitude of the sft and 2sft frequency, while the scenario for the elastic recovery coefficient witnessed a reverse trend. The amplitude of the 0.5sft frequency decreased with the increase of the radial runout offset, while the amplitude of sft frequency increased as the radial runout offset increased; the scenario for the influence of the radial runout angle was opposite. The increase of the axial runout offset could lead to the increase of the amplitude of both 0.5sft and sft frequency. The increase of corner radius could lead to a slight reduction of the amplitude of the 0.5sft and sft frequency. The occurrence of the vibration with high frequency leaded to a low spatial frequency. The corresponding tool wear experiment was conducted, and the frequency-spectrum characteristics of the micro-milled surface were compared with the simulated results to validate the established profile models. The paper successfully correlated the relative importance of the identified individual factors to the corresponding frequency spectrum characteristics, and it had potential applications in predicting and controlling the spatial content of machined surfaces.

Simulation of melt film dynamics in laser fusion cutting using a boundary layer approximation

Process inherent instabilities in the dynamics of the thin melt film during laser fusion cutting reduce the quality of the cut surface with regards to mean profile height and angular tolerance. To enhance the process understanding and to identify and evaluate quality improvement measures, a 3D model of the melt film dynamics is developed and applied to experimental results from literature. To cope with the multi-scale character of the mathematical task, model reduction techniques are applied: the underlying transport equations are mapped to a conformal coordinate system and subjected to a scaling analysis. By using a perturbation series, the most significant contributions to the equations of motion are selected. An integral boundary layer approximation reduces the dimension of the numerical task to a two-dimensional problem that can be solved with very low computational effort. The resulting simulation is able to reflect the dynamics at a spatial resolution below Δx≤25μm and a temporal resolution below Δt≤2.5μs within a reasonable calculation time of a few days for a cut length of L=10mm and a cut thickness of a=3mm. Known correlations between process parameters and quality features are reproduced by this simulation. Results show that a concurrent improvement of mean profile height and angular tolerance cannot be obtained by straightforward measures like changing the beam profile from tophat to Gaussian and vice-versa. Future work will be focused on the extension of this model with regards to surface tension and evaporation.

Rational parameters of the transportless technological scheme for the development of strata with maximum permissible dip angle

In this article the rational value of overburden cut width and thickness of transportless overburden at mining of two dispersed flat seams IV-V and VI at Kureinsky section of Sibirginsky open pit mine are presented, which makes it possible to minimize the volume of rock re-excavation under the condition of the planned annual productivity of coal on the open pit and to ensure reduction of stripping costs. This task is complicated by the fact that the dip angle at the section is close to the limit on the condition of the possibility of spoiling of internal dump, and since the overburden rocks of the section are represented mainly by large-block sandstones on the clay cement and siltstones and their compressive strength is 60-80 MPa, then it is required to use a drilling and blasting method of their preparation for excavation. Under such conditions, optimizing the parameters of the transportless excavation scheme is of special importance for effective mining of the section.

Accuracy and surface quality of abrasive waterjet machined CFRP composites

The use of carbon fiber-reinforced composites is increasing today since they have an excellent weight-to-mechanical properties ratio. Traditional machining of this material is difficult. Abrasive water jet machining (AWJM) is an advanced non-traditional material removal process that can machine hard-to-cut materials. The process is widely used in aerospace, marine, and automotive industries. However, it encounters several challenges when cutting carbon fiber reinforced polymers (CFRP). The present work aims to study the characteristics of AWJM of CFRP laminates. Detailed experimental investigations are conducted to explore the effect of traverse feed and standoff distance (SOD) on top kerf width, bottom kerf width, kerf angle, profile area, volumetric removal rate, and the average surface roughness, and jet deviation factor. Repeatability tests are also used to assess the kerf dimensional accuracy and surface roughness tolerance achieved by AWJM of CFRP laminates. Results showed that the surface roughness increases along with the cut thickness, especially at large traverse feed and SOD. Both the kerf taper angle and the volumetric removal rate increase with traverse feed and SOD.

MODELING OF THE GRINDING PROCESS BY MICRO-CUTTING SINGLE ABRASIVE GRAINS. PART 1. DETERMINATION OF THE STRENGTH OF ABRASIVE GRAINS

Main performance indicators of grinding wheels are the strength and wear resistance of abrasive grains. The description of the installation for studying the process of micro-cutting of various materials with single abrasive grains, which allows you to approximate the working conditions of a single abrasive grain to the conditions of real grinding in a wide range of cutting speeds. The effect of the cutting speed on the maximum cut thickness maintained by the grain vertexes without their destruction is shown. The influence of physical and mechanical properties of the workpiece material and the abrasive tool material, together with technological factors, on the micro-cutting process is considered.