Reaming operation

Hand reamers are made of hardened, brittle materials, so extra care is needed during use to ensure strict alignment between the reamer and the hole axis to prevent breakage. When manually reaming, CNC operators must ensure that only a small amount of material is removed each time, maintaining precise alignment between the reamer and the hole axis to avoid tool damage or reduced machining accuracy due to improper operation.

In terms of precision requirements, reaming operations can typically achieve high dimensional accuracy and surface roughness requirements. Through proper process planning and operational control, dimensional accuracy of IT9 to IT7 levels and surface roughness of Ra3.2 to 0.8 can be achieved.

Carbide reamers are cutting tools made of carbide material, known for their high hardness and wear resistance, making them suitable for machining high-hardness, high-strength materials such as stainless steel, titanium alloys, etc. Carbide reamers are mainly divided into straight flute reamers and spiral flute reamers, used to ream holes that have been drilled (or expanded) on workpieces to improve the machining accuracy and reduce surface roughness.

Uses of reamerpdf

Reaming is commonly used for holes with diameters up to 100mm. When reaming on a machining center, the typical process is drilling (or boring) the hole followed by reaming. For holes with a diameter less than 12mm, the process is adjusted due to the slightly lower rigidity of the reaming tool. The process for smaller holes typically involves spotting, drilling (or boring), and then reaming to ensure the straightness and concentricity of the hole.

During the machining process, attention should be paid to the selection of allowances, control of cutting speed and feed rate, use of cutting fluid, and assurance of machining accuracy. Through proper operation and control, efficient and high-quality hole machining can be achieved.

\({\left( {{{{d_g}} \over 2}} \right)^2} = {\left( {{{{d_g}} \over 2}} \right)^2} – 2.{{{d_g}} \over 2}.\delta  + {\delta ^2} + {r^2}\)

The amount of material to leave for reaming, often referred to as the reaming allowance or reaming stock. Typically, leave approximately 1/32″ to 1/16″ (0.8mm to 1.6mm) of material for reaming.

However, in the initial stages of part drilling, most manufacturers tend to use drill bits for rapid cutting. Drill bits, with their efficient material removal capability, can quickly create initial holes in parts. However, it’s worth noting that drill bits are primarily aimed at swiftly removing large amounts of material rather than achieving high precision hole diameters. Therefore, for parts requiring high precision machining, opting for the reaming process is the right choice. In addition, if you want to gain a deeper understanding of the differences between drilling, boring, and reaming, it is recommended that you read the following articles in depth to gain a more comprehensive understanding of the characteristics and advantages of these machining processes, so that you can choose the most suitable process to meet your part manufacturing needs.

Shell reamers are primarily used for machining larger holes, typically with diameters of 19 mm and above. They can feature any standard flute type, including straight, twisted, and spiral flutes. Different flute types are suitable for different machining needs. When using shell reamers, it is important to maintain tool stability and accuracy to avoid excessive wear or damage.

A floating reamer is a special type of cutting tool typically mounted on a floating reamer holder, which carries the collet or chuck through an independent bearing system. This design allows for correction of misalignment between the drilled and reamed tool axis, ensuring machining accuracy. It features two replaceable and adjustable cutting edges, fixed in a groove on the reamer, allowing radial float to adapt to different machining requirements.

In this guide, BoYi will delve into the definition of reaming, its working principles, applications, various types of reamers, and how to utilize them to achieve unparalleled precision.

3 typesofhand reamers

Step 1: Select a typical workpiece according to machining requirements. For example, aluminum alloy, with moderate hardness, is suitable for reaming operations. Choose a reamer with a diameter of 8mm.

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Useof reamerin Endodontics

Step 3: Insert the reamer into the pre-drilled hole, maintaining the tool’s vertical and horizontal position. Gently rotate the handle to slowly feed the reamer into the workpiece. During the cutting process, observe the chip evacuation, and use an air gun if necessary to prevent chip accumulation from affecting cutting.

Reaming is a critical precision machining method that demands precise operational steps and considerations to ensure optimal machining results. Below is a detailed guide for reaming operations:

The purpose of reaming the tube before flaring is to remove any burrs, irregularities, or debris from the inner surface of the tube. This ensures a clean, smooth surface for the flare to form properly, resulting in a secure and leak-free connection.

Although hand reamers perform well in light cutting operations, their accuracy may not be comparable to machine reamers due to the influence of manual operation factors. Therefore, in applications requiring strict tolerance control, hand reamers may not be the best choice.

Step 4: Set appropriate cutting parameters based on the workpiece material and reamer characteristics. Control cutting speed at 150rpm and feed rate at 0.1mm/rev. Generally, for harder materials, reduce cutting speed and feed rate; for softer materials, increase cutting speed and feed rate appropriately.

or, \({MRR_{ductile}}\) = \({2 \over 3}\pi {\left( {{d_g}\delta } \right)^{3/2}}{{{M_g}} \over {{4 \over 3}\pi {{\left( {{{{d_g}} \over 2}} \right)}^3}{\rho _g}}}\)

However, carbide reamers are extremely brittle, so they must be handled and used with extreme care to avoid fracture and breakage. Additionally, selecting and using cutting fluid is crucial for achieving the best machining results. For example, when machining steel parts, a 10% to 15% concentration emulsion or sulfurized oil is typically used as cutting fluid, while machining castings requires the use of petroleum with good wetting properties and low viscosity. Moreover, cutting fluid must be continuously and adequately supplied to prevent the carbide reamer’s cutting edges from fracturing.

Again, work done required to create an indentation of depth δ in work material having hardness H is: W.D. = (Average resisting force) × (Depth of penetration)

The advantages of a floating reamer lie in its simple fixture design, easy fabrication, and low cost. It offers high-quality machining, with reamed hole accuracy reaching IT6~IT8 and surface roughness typically ranging from Ra0.8~Ra1.6 or even smaller, meeting high-precision machining requirements. It is particularly suitable for use on boring mills, CNC machining centers, or turn-mill machining centers for applications requiring high-precision reaming.

Reaming is a process focused on refining existing holes (typically performed after drilling or boring) to precision machine the inner surface of the hole. It involves using a cutting tool called a “reamer” to lightly shave the inner walls of the hole, precisely enlarging the existing aperture, and enhancing the surface smoothness of the hole walls. This tool is specifically designed for precision machining, with a low material removal rate that further refines the inner surface quality of the hole, meeting the high precision requirements of parts.

A hand reamer is a precision-ground cutting tool designed for manual operation, used to manually enlarge pre-drilled holes to precise diameters. These types of reamers typically feature straight or slightly twisted flute designs, with the tip portion having a slight angle and tapered lead-in. This design allows the reamer to easily enter at precise angles during manual operation, especially in situations where there is no machine locking or fixation, although it is not suitable for CNC machines.

This article was written by engineers from the BOYI team. Fuquan Chen is a professional engineer and technical expert with 20 years of experience in rapid prototyping, mold manufacturing, and plastic injection molding.

Shell reamers are cutting tools that increase their diameter by rotating a screw, causing the cutting edges to move radially outward. This design not only allows the tool to self-compensate for wear but also enables fine control over different hole diameters. Shell reamers can only remove relatively small amounts of material during the cutting process and may not be as durable as some other more robust tools.

or, \({MRR_{brittle}}\) = \(4.{M_g}.{d_g}^{( – 3/2)}.\left\{ {{d_g}^{3/2}.{U^{3/2}}.{\rho _g}^{3/4}{{.6}^{ – 1/4}}.{H^{ – 1/4}}} \right\}.{\rho _g}^{ – 1}\)

In the machining of components for the automotive and aerospace industries, there are numerous precision assembly holes. They demand strict positional tolerances and high surface roughness requirements. If you’re seeking a professional reaming service provider, BoYi would be your best choice. We possess advanced reaming equipment and a proficient technical team to ensure that every workpiece undergoes meticulous reaming, meeting your expectations for dimensional accuracy and surface quality.

There are numerous types of reamers, each carefully crafted for specific purposes. In mechanical machining, various types of reamer tools are commonly used, each with unique characteristics and applications. Below, I will detail several common types of reamer tools, along with their specific purposes and usage methods.

What is areamerused for in Dentistry

Reaming is one of the precision machining methods for holes, employing a rotational cutting tool. It allows for precisely trimming holes on workpieces, ensuring smooth and accurate inner dimensions. For instance, in plastic products such as plastic pipes and connectors, reaming enhances the accuracy and connectivity of the holes. In metal products like engine blocks, bearings, and turbines, reaming is utilized for meticulous machining to achieve the required dimensional accuracy and surface roughness.

How to use areameron a lathe

In summary, reaming is a crucial machining process and method of object connection, widely applied across various fields. This article has provided a detailed overview of what reaming is, its working principle, applications, advantages and disadvantages, types of reamers, and when to use reaming. If you need more information or services related to reaming, please contact the Boryi expert team. We prioritize communication and collaboration with our clients, striving to understand your needs and requirements thoroughly to ensure the delivery of the highest quality service experience. Click here to contact us.

\({V_{brittle}} = {1 \over 2}\left( {{4 \over 3}\pi {r^3}} \right)\) or, \({V_{brittle}} = {2 \over 3}\pi {\left\{ {{d_g}.\delta } \right\}^{3/2}}\) [From eq(i)]

The primary purpose of reaming is to improve the accuracy, surface finish, and diameter of a previously drilled or machined hole. It removes any remaining material, burrs, or imperfections left behind by the initial drilling or machining process. This ensures that the hole meets precise dimensional requirements and is suitable for various applications such as fitting components, creating smooth surfaces for seals, or facilitating assembly processes like threading or inserting fasteners.

The advantages of carbide reamers lie in their sharp and smooth cutting edges, resulting in smooth hole walls with a surface finish of up to Ra0.25. They offer swift and smooth cutting, excellent chip evacuation, good machine shock resistance, and can maintain hole accuracy tolerances up to 1μ. In batch production, they can be used on machine tools to ream holes in both common and hard-to-machine materials. They are also suitable for CNC reaming for deburring and controlling hole tolerance levels.

ReamerTool

Step 5: Once the cutting edge fully enters the workpiece, continue rotating the handle smoothly to guide the tool through the workpiece until the reamer’s cutting edge contacts the workpiece surface. Then, withdraw the reamer by rotating it counterclockwise.

Furthermore, to avoid chip buildup during reaming, lower cutting speeds are typically used. For example, when high-speed steel reamers are used for machining steel and cast iron, the cutting speed should be below 8m/min, with a feed rate commonly ranging from 0.3mm/r to 1mm/r. As the hole diameter increases, the feed rate value also increases.

Reamermachine

To ensure the quality and efficiency of reaming operations, it is essential to have a thorough understanding of its application and considerations.

Now, volume of material removed by single grit for ductile and brittle materials: Vductile = Volume of a portion of hemisphere of depth δ

For ductile materials, volume of material removed by single impact is equal to the volume of single indentation; whereas, for brittle materials, the volume of material removed by single impact is equal to the volume of hemispherical crater having diameter equals to chord length of the indentation, as depicted below.

or, \({MRR_{brittle}}\) = \({2 \over 3}\pi {\left( {{d_g}\delta } \right)^{3/2}}.{{{M_g}} \over  {{4 \over 3}\pi {{\left( {{{{d_g}} \over 2}} \right)}^3}{\rho _g}}}\)

Knowledge of material removal rate (MRR) of abrasive jet machining (AJM) is beneficial for selecting process parameters and choosing feed rate of the nozzle. It also facilitates estimation of productivity, delivery time as well as production cost. Since only kinetic energy of abrasive grits is utilized for erosion, the analytical formula for MRR can be established by equating available kinetic energy with the amount of work required for creating an indentation of certain cord length on a specific work material. However, ductile and brittle materials behave differently in indentation formation, and thus size of indentation created by the impact of single abrasive grit is different for ductile and brittle materials. The steps for mathematical modeling of MRR in AJM are elaborated in following sections. This model is based on few assumptions, follow the below link for those assumptions.

or, \({MRR_{ductile}}\) = \(3.{M_g}.\left\{ {{d_g}^2.{U^2}.{\rho _g}{{.6}^{ – 1}}.{H^{ – 1}}} \right\}.{d_g}^{ – 2}.{\rho _g}^{ – 1}\)

The amount of allowance in reaming affects the cutting load of the reamer, surface finish, and dimensional tolerance. Therefore, during rough reaming and finish reaming processes, the rough reaming allowance should be controlled between 0.35mm to 0.15mm, while the finish reaming allowance should be controlled between 0.15mm to 0.05mm. This ensures removal of tool marks from previous processes while maintaining the cutting performance of the reamer and the quality of the machined surface.

Step 6: After reaming, conduct a comprehensive inspection and measurement of the machined holes. Use a brush to clean the hole bottom and walls, deburring. Utilize high-precision measuring tools to measure the diameter, depth, and surface finish of the holes. The diameter error of the hole should be within ±0.01mm, and the surface finish should meet the requirement of Ra0.8.

Step 2: Use a 7.8mm diameter spotting drill for pre-drilling. The tapered design of the spotting drill helps ensure stability during reaming. The depth of the pre-drilled hole is 20mm, providing a good initial condition for subsequent reaming operations.