Drilling Machine Operations: Boring, Reaming, Counter Sinking, Spot Facing, Tapping | Shubham Kola

Shubham Kola

3 May 202102:37

Summary

TLDRThis session covers various drilling machine operations, including drilling, reaming, boring, counter sinking, counter boring, spot facing, and tapping. Drilling creates cylindrical holes, while boring refines and corrects the size and roundness of pre-existing holes. Reaming smooths and sizes holes post-drilling. Spot facing creates a flat surface for fasteners. Tapping creates internal threads, and counterboring enlarges hole ends cylindrically. Countersinking forms a conical enlargement at the hole's end, with tools featuring multiple cutting edges.

Takeaways

🔩 Drilling operation involves creating a cylindrical hole by rotating a cutting tool called a drill, which leaves a rough internal surface and results in a hole slightly larger than the drill size.
📏 Boring operation is used to increase the diameter of an existing hole, often to correct its roundness and finish the internal surface, using a single-edged boring tool placed in a tapered boring bar.
🔧 Spot Facing operation is performed to produce a flat surface at the top of a drilled hole for seating bolt heads, washers, or nuts, aiming to achieve a high surface finish.
🔨 Tapping operation uses a tap as a cutting tool to create internal threads that match the size of external threads, which can be done manually or with external power.
⚒ Counterboring operation enlarges the end of a hole cylindrically, using a counterbore tool with cutting edges that may be straight or spiral, typically at a slower speed than drilling.
🔧 Reaming operation refines the size and finish of a hole after the initial drilling process, using a reamer, which is a multi-point cutting tool.
🔩 Countersinking operation creates a conical enlargement at the end of a hole, with the countersink tool featuring multiple cutting edges on its conical surface, and the included angle of the cone ranging from 60 to 90 degrees.
🛠 The speed of spindle in boring is less than that in reaming, indicating a slower process for achieving the desired hole finish.
🔗 Tapping can be performed by hand or with external power, demonstrating flexibility in the operation depending on the application and available equipment.
🔧 Reaming is essential for achieving the desired hole size and improving the internal surface finish, especially after the initial drilling process which often leaves an imperfect hole.

Q & A

What is the primary purpose of a drilling operation?
-The primary purpose of a drilling operation is to produce a cylindrical hole inside a workpiece by rotating the cutting edge of a tool called a drill.
Why is the internal surface of a hole usually rough after drilling?
-The internal surface of a hole is usually rough after drilling because the process involves the rapid removal of material by the rotating drill, which can leave behind an uneven surface.
What is the difference between drilling and boring operations?
-Drilling creates a hole in the workpiece, while boring is used to increase the diameter of an existing hole, often to improve its surface finish and correct its roundness.
How does the boring tool differ from a drill?
-The boring tool has only one cutting edge and is placed in a boring bar with a tapered shank, unlike a drill which is used for initial hole creation.
What is the purpose of spot facing operation?
-Spot facing is used to produce a flat seat for bolt heads, washers, or nuts at the opening of a drilled hole, providing a high surface finish at the top of the hole.
What is the function of a tap in a tapping operation?
-A tap is used in a tapping operation to create internal threads that can mate with external threads of identical size, effectively cutting threads into the hole.
Can tapping be performed manually or does it require external power?
-Tapping can be performed manually, but it can also be done using external power for increased efficiency and precision.
What is the primary goal of a counterboring operation?
-The primary goal of a counterboring operation is to enlarge the end of a hole cylindrically, using a counterbore tool with cutting edges that may be straight or spiral.
Why is the cutting speed in counterboring usually slower than drilling?
-The cutting speed in counterboring is usually slower than drilling because it is a precision operation that requires careful control to avoid damaging the workpiece, with speeds typically being around 25% smaller.
What is the main objective of reaming operation?
-Reaming is done to obtain the desired size of a hole and to finish the internal surface properly, using a reamer which is a multi-point cutting tool.
How does countersinking operation differ from other hole enlargement operations?
-Countersinking operation differs from other hole enlargement operations by creating a conical-shaped enlargement at the end of a hole, with the countersink tool having multiple cutting edges on its conical surface.

Outlines

00:00

🛠️ Drilling Machine Operations

This paragraph introduces various operations performed by a drilling machine, including drilling, reaming, boring, counter sinking, counter boring, spot facing, and tapping. Drilling creates a cylindrical hole by rotating a cutting tool called a drill. The internal surface of the hole is typically rough and larger than the drill size. Boring is used to increase the diameter of a previously drilled hole, often to correct roundness and finish the hole to a required size. The boring tool has a single cutting edge and is placed in a tapered shank boring bar. Spot facing is used to produce a flat surface for a bolt head, washer, or nut at the opening of a drilled hole, providing a high surface finish. Tapping involves using a tap to create internal threads that can mate with external threads of identical size. Counterboring enlarges the end of a hole cylindrically, using a counterbore tool with cutting edges that may be straight or spiral. Reaming is performed to achieve the desired hole size and to finish the internal surface, using a reamer, which is a multi-point cutting tool. Countersinking creates a conical enlargement at the end of a hole, with the countersink tool featuring multiple cutting edges on its conical surface.

Mindmap

Keywords

💡Drilling

Drilling is a cutting process that uses a drill, a rotating cutting tool, to create a cylindrical hole in a workpiece. It is a fundamental operation in metalworking and is crucial for creating holes for assembly or fastening components. In the video's context, drilling is described as a process where material is removed by rotating the edge of the cutting tool, resulting in a rough internal surface that is larger than the drill size.

💡Reaming

Reaming is a finishing operation that follows drilling and is used to improve the size, shape, and surface finish of a hole. It involves using a reamer, a multi-point cutting tool, to achieve a more precise and smooth hole. The video script highlights that reaming is done to obtain the desired size of the hole and to finish the internal surface properly, which is essential for fitting components accurately.

💡Boring

Boring is an operation used to enlarge an existing hole to a specific size and improve its surface finish. It is particularly useful for refining holes that were initially produced by casting processes. The video mentions that boring corrects the roundness of the hole and is performed with a boring tool that has only one cutting edge, placed in a tapered shank boring bar.

💡Countersinking

Countersinking is a machining process that creates a conical-shaped enlargement at the end of a hole. This operation is used to prepare a hole for a flat-headed screw or to create a countersunk hole. The video script describes that the included angle of the conical surface can vary from 60 to 90 degrees, and countersink tools have multiple cutting edges on their conical surface.

💡Counterboring

Counterboring is the process of enlarging the end of a hole in a cylindrical manner, typically to accommodate a bolt head or a washer. The video script explains that counterbore tools have cutting edges, which can be straight or spiral, and that the cutting speed in this process is usually slower than in drilling, being about 25% smaller.

💡Spot Facing

Spot facing is a process used to produce a flat surface at the opening of a drilled hole. It is often used to provide a seat for bolt heads, washers, or nuts, ensuring a flush fit. The video script mentions that spot facing is used to give a high surface finish at the top of the hole, which is important for the aesthetic and functional integrity of the assembly.

💡Tapping

Tapping is the process of cutting internal threads in a hole. It involves using a tap, which acts as a cutting tool, to create threads that can mate with external threads of the same size. The video script explains that tapping can be done manually or with external power and is essential for assembling threaded fasteners.

💡Cutting Tool

A cutting tool is an instrument used to remove material from a workpiece through a cutting process. Drills, reamers, boring tools, countersinks, and taps are all examples of cutting tools. The video script describes how these tools are used in various machining operations to shape and finish holes for different purposes.

💡Spindle Speed

Spindle speed refers to the rotational speed of a machine tool's spindle, which is the part that holds the cutting tool. The video script mentions that the spindle speed in boring is less than in reaming operations, indicating that different operations require different speeds to optimize the machining process and achieve the desired finish.

💡Multi-Point Cutting Tool

A multi-point cutting tool is a tool with multiple cutting edges, which allows for more efficient and precise machining. Reamers, as mentioned in the video script, are examples of multi-point cutting tools used to refine the size and finish of a hole after initial drilling.

💡Surface Finish

Surface finish refers to the smoothness and texture of a machined surface. It is an important aspect of machining operations as it can affect the fit and function of assembled parts. The video script emphasizes the importance of achieving a high surface finish in operations like spot facing and reaming, which contribute to the quality of the final product.

Highlights

Drilling operation produces a cylindrical hole by rotating a cutting tool called a drill.

Drilled holes are typically rough and larger than the drill size.

Boring operation enlarges a previously produced hole to improve its internal surface finish.

Boring is used to correct the roundness of holes and achieve the required size.

The boring tool has a single cutting edge and is placed in a tapered shank boring bar.

Spot Facing Operation creates a flat seat for bolt heads, washers, or nuts at the hole opening.

Tapping operation uses a tap to create internal threads that match external threads of the same size.

Tapping can be done manually or with external power.

Counterboring enlarges the end of a hole cylindrically using a counterbore tool with cutting edges.

Counterboring has a slower cutting speed, about 25% less than drilling.

Reaming is done to achieve the desired hole size and improve the internal surface finish after drilling.

A reamer is a multi-point cutting tool used in the reaming process.

Countersinking operation creates a conical enlargement at the end of a hole, with angles ranging from 60 to 90 degrees.

Countersink tools have multiple cutting edges on their conical surface.

Drilling machines are versatile and can perform various operations like drilling, reaming, boring, and tapping.

The internal surface finish of a hole is a critical factor in many machining processes.

The selection of cutting speed is crucial for the efficiency and quality of the machining process.

Multi-point cutting tools like reamers are essential for achieving precision in hole sizing.