Search Results for internal grinding

Metal is removed from the workpiece by the mechanical action of irregularly shaped abrasive grains in all grinding operations. This article discusses three primary components of grinding wheels, namely, abrasive (the cutting tool), bond (the tool holder), and porosity or air for chip clearance and/or the introduction of coolant. It describes the compositions and applications of coated abrasives and types of grinding fluids, such as petroleum-base and mineral-base cutting oils, water-soluble oils, synthetic fluids, semisynthetic fluids, and water plus additives. The article concludes with information on different types of grinding processes, namely, rough grinding, precision grinding, surface grinding, cylindrical grinding, centerless grinding, internal grinding, and tool grinding.

This article describes the selection of tool steels on the basis of specific product applications. It contains tables that list nominal speeds and feeds for the machining of various tool steels. The machining processes include turning, boring, broaching, drilling, reaming, tapping, milling, and sawing. The article explains the machining of the following tool steels: water hardening; types A, D and O cold-work; hot work; high speed, low-alloy special-purpose; and low-carbon mold. It details the machining of tool steel gears. The article also discusses the grinding of tool steels based on steel classification and the effects of steel composition and hardness on grindability. It reviews the types of grinding, namely, surface grinding, cylindrical grinding, centerless grinding, internal grinding, thread grinding, flute grinding, and low-stress grinding. Grinding of types-A, D, F, L, O, P, S and W steels, hot-work steels, and high speed steels, is also detailed.

This article describes the various characteristics of electrochemical grinding (ECG). It discusses grinding methods that can be performed with ECG components, namely, the electrolyte delivery and circulating system, the electrolyte, the DC power supply, grinding wheel, and the workpiece. Grinding, surface grinding, internal grinding, form grinding, and cylindrical grinding are discussed. The article also lists the advantages, disadvantages, and applications of ECG.

This article discusses the different classes of gears, namely, spur, helical, herringbone, crossed-axes helical, worm, internal, rack, bevel, or face-type. It describes the methods used to cut the teeth of gears other than bevel gears: milling, broaching, shear cutting, hobbing, shaping, and rack cutting. The article also reviews the methods that are used to cut the teeth of bevel gears, such as face mill cutting, face hob cutting, formate cutting, helix form cutting, the Cyclex method, and template machining. The machining methods best suited to specific conditions are discussed. The article presents the factors influencing the choice of cutting speed and cutting fluids. It outlines two basic methods for the grinding of gear teeth: form grinding and generation grinding. The article concludes with information on the gear inspection techniques used to determine whether the resulting product meets design specifications and requirements.

This article reviews the steps involved in presurface-preparation inspection: substrate replacement; removal of weld spatter, rounding of sharp edges, and grinding of slivers/laminations; and removal of rust scale, grease, oil, and chemical (soluble salt) contamination. It focuses on surface preparation methods that range from simple solvent cleaning to hand and power tool cleaning, dry and wet abrasive blast cleaning, centrifugal wheel blast cleaning, chemical stripping, and waterjetting for the application of the coating system. In addition, the article provides a description of the Society for Protective Coatings' (SSPC) standards and NACE International standards as well as the International Organization for Standardization (ISO) standards and International Concrete Repair Institute (ICRI) guidelines for surface cleanliness.

Thread rolling is a cold-forming process for producing threads or other helical or annular forms by rolling the impression of hardened steel dies into the surface of a cylindrical or conical blank. Methods that use cylindrical dies are classified as radial infeed, tangential feed, through feed, planetary, and internal. This article focuses on the capabilities, limitations, and machines used for these methods. It describes the three characteristics, such as rollability, flaking, and seaming, used in evaluating and selecting metals for thread rolling. The article explores the factors affecting die life and explains the effect of thread form on processing. It provides information on various fluids used in thread rolling to cool the dies and the work and to improve the finish on the rolled products. The article provides a comparison between thread rolling and cutting, as well as between thread rolling and grinding.

This article discusses the three characteristics that are important in evaluating and selecting metals for thread rolling, namely, rollability, flaking, and seaming. It reviews the capabilities and limitations of flat-die rolling, radial-infeed rolling, tangential rolling, through-feed rolling, planetary thread rolling, continuous rolling, and internal thread rolling, as well as the rolling machines and dies used. The article describes the factors affecting die life and provides information on radial die load, seam formation, surface finish, and thread dimensions that are affected by the form of the thread. It explains the reasons for using fluids in thread rolling. The article concludes with a comparison of rolling with cutting and grinding.

Cold-finished steel bars are carbon and alloy steel bar products (round, square, hexagonal, flat, or special shapes) that are produced by cold finishing previous hot-wrought bars. by means of cold drawing, cold forming, turning, grinding, or polishing (singly or in combination) to yield straight lengths or coils that are uniform throughout their length. Cold-finished bars fall into five classifications: cold-drawn bars; turned and polished bars; cold-drawn, ground, and polished bars; turned, ground, and polished bars; cold-drawn, turned, ground, and polished bars. Different size tolerances are applicable to cold-finished products, depending on shape, carbon content, and heat treatment. When used to identify cold-finished steel bars, the various quality descriptors are indicative of many characteristics, such as degree of internal soundness, relative uniformity of chemical composition, and relative freedom from detrimental surface imperfections. Cold drawing significantly increases machinability, tensile and yield strengths of steel bars. Two special die-drawing processes have been developed to give improved properties over those offered by standard drawing practices. These processes are cold drawing using heavier-than-normal drafts, followed by stress relieving; and drawing at elevated temperatures.

This article provides a discussion on a working principle, the operations, characteristics, capabilities, and applications of electrochemical grinding (ECG). The basic elements of the ECG machine tool are also presented.

This article discusses the principles of grinding process. It illustrates a typical wheel-work characteristic chart relating surface finish, wheel wear rate, metal removal rate, and power to the normal force. The article also reviews the effect of variations in work material, wheel specification, wheel speed, coolant, and grinding wheel-work conformity on the slopes of the wheel-work characteristic chart.

In all grinding operations, care must be used in the selection of wheels and abrasive belts to meet finish and tolerance requirements without damaging the workpiece. This article discusses the major aspects of the grinding wheel, including production methods, selection considerations, standard marking systems, abrasives, and bonding types. It compares bonded wheel grinding with abrasive belt grinding. The article reviews the types of grinding fluids and discusses their importance in grinding operations. It describes the specific grinding processes and provides recommendations for grinding and grinding wheels.

This article discusses the various elements of thread grinding processes, including thread grinding machines, tolerances, wheel selection, grinding speed, and grinding fluids. It describes truing of grinding wheels and reviews the process applications. In addition, the article describes the five basic methods employed for cylindrical thread grinding, namely, single-rib wheel traverse grinding, multirib wheel traverse grinding, multirib wheel plunge grinding, multirib wheel skip-rib, or alternate-rib, grinding, and multirib wheel three-rib grinding. It also provides an overview of centerless grinding of threads and high-volume applications of thread grinding.