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Drilling Operations and Machines
Published in Zainul Huda, Machining Processes and Machines, 2020
Drilling is a machining operation that produces a hole in a solid by rotating and pressing a cutting tool (drill bit) with multiple cutting edges. In drilling, the drill bit is rotated at rates from hundreds to thousands of revolutions per minutes and pressed against the workpiece thereby resulting in cutting-off chips from the hole as it is drilled (see Figure 6.1). In engineering manufacture, drilling and related operations may be performed to either create a new hole or to enlarge existing hole in a cast metallic component or pre-machined holes in a work-part.
Electrical installation methods, procedures and requirements
Published in Trevor Linsley, Electrical Installation Work Level 2, 2019
Cordless electric drills are also available which incorporate a rechargeable battery, usually in the handle. They offer the convenience of electric drilling when an electrical supply is not available or if an extension cable is impractical.
Safe Work Practices for Water, Wastewater, and Environmental Professionals
Published in Frank R. Spellman, Kathern Welsh, Safe Work Practices for Wastewater Treatment Plants, 2018
Frank R. Spellman, Kathern Welsh
When using an electric drill, secure work by using a clamp, jig, or vise. Never hold small work in the hand while drilling. Use adequate eye protection, and be sure to remove the chuck key or drift before starting to drill.
CFNN-PSO: An Iterative Predictive Model for Generic Parametric Design of Machining Processes
Published in Applied Artificial Intelligence, 2019
Tamal Ghosh, Kristian Martinsen
Drilling is a traditional cutting process of materials using drill bit as a cutting tool, which makes circular holes on the workpiece. The chosen tool rotates along the axis and often used as a multi-point tool, which put force against the work-piece while in rotation (100–10000 rpm). This phenomenon removes material as chips with certain rate while generating the desired shape. Drilling operation could create some low residual stresses around the cut hole and accumulate highly deformed material on the generated surface. Hence, a finish operation could be required after drilling operation to avoid corrosions (Anand et al. 2018). In general spindle speed, feed rate, and drill diameter are considered as important process parameters for drilling process, whereas Ra, MRR, thrust force, and torque generated during drilling process are most important performance indicators. Various design of experiments (DOE) methods such as factorial design, Taguchi’s method, response surface method (RSM), and gray relational analysis (GRA) are applied yet for optimization of the drilling process (Anand et al. 2018; Onwubolu and Kumar 2006).