What is reaming?

Reaming is a machining process used to finish and enlarge the diameter of a previously drilled hole to a certain tolerance. The primary objective of reaming is to improve the accuracy, surface finish, and dimensional precision of the hole. This process is essential when tight tolerances and a smooth surface finish is required for components in various industries, such as automotive, aerospace, and manufacturing. Reaming helps eliminate any irregularities, burrs, or deviations left by the initial drilling process. The result is a precisely sized and high-quality hole that meets the specified engineering standards, usually to a h7 tolerance. Reaming can be performed by hand or on manual and CNC machines.

Hand Reamers vs Machine Reamers

Hand Reaming

Machine Reaming

HSS vs Carbide Reamers

High Speed Steel (HSS) and carbide reamers are both cutting tools used in machining processes, yet they have some key differences:

HSS Reamers

Reaming is a machining process used to finish and enlarge the diameter of a previously drilled hole to a certain tolerance. The primary objective of reaming is to improve the accuracy, surface finish, and dimensional precision of the hole. This process is essential when tight tolerances and a smooth surface finish is required for components in various industries, such as automotive, aerospace, and manufacturing.

Reaming helps eliminate any irregularities, burrs, or deviations left by the initial drilling process. The result is a precisely sized and high-quality hole that meets the specified engineering standards, usually to a h7 tolerance. Reaming can be performed by hand or on manual and CNC machines.

Carbide Reamers

Made from a composite material of tungsten carbide and cobalt, providing exceptional hardness and durability. Carbide reamers excel in applications involving tough materials, high-speed machining, and extended tool life.

HSS vs Carbide Reamers

While HSS reamers are generally more cost-effective, carbide reamers are favoured for their superior performance in demanding machining applications. The choice between HSS and carbide reamers depends on the specific machining requirements and the materials being machined.

What are the different types of machine reamer?

There are various types of reamers designed to meet specific machining needs:

• Straight-fluted reamers feature straight cutting edges and are suitable for through holes in softer materials.
• Spiral-fluted reamers, with helical cutting edges, are effective for blind holes and materials that produce long chips.
• Tapered reamers gradually enlarge holes, often used for aligning and fitting parts.
• Chucking reamers are short and rigid, ideal for use in a pillar drill or lathe.
• Hand reamers, operated manually, provide precision in smaller-scale applications.
• Adjustable reamers allow for diameter adjustments, providing versatility in hole sizing.
• Carbide-tipped reamers are durable and perform well in high-speed applications, while diamond-coated reamers offer exceptional hardness for abrasive materials.

Choosing the appropriate reamer type depends on factors like hole type, material, precision requirements, and the specific machining application.

What is the difference between spiral flute and straight flute reamers?

Spiral flute and straight flute reamers differ due to their cutting edge. Spiral flute reamers feature helical cutting edges that aid in efficient chip evacuation, making them suited for blind hole applications and materials prone to long chips. The spiral design also reduces chatter and enhances stability during the machining process.

Straight flute reamers have parallel cutting edges, making them suitable for through holes and softer materials. The straight design improves chip removal but may be more prone to vibration in certain applications. Choosing between the two depends on the specific machining application.

Spiral flute reamers are preferred for enhanced chip evacuation and stability, especially in blind hole scenarios, while straight flute reamers are suitable for through holes and softer materials.

Why would you use a modular reamer?

The use of modular reamers can offer improved efficiency and adaptability. Modular reamers offer a customisable and interchangeable design, allowing users to replace or adjust individual components without changing the entire tool, resulting in cost savings and reduced downtime. This versatility makes them particularly advantageous in situations where multiple hole sizes or materials need machining.

The modular design facilitates quick adjustments, improving the tool's adaptability to various machining requirements. Whether tackling diverse projects or accommodating advanced machining needs. the modular reamer proves to be a versatile tool, providing a flexible and efficient solution for precision hole making application where various diameters are required but with the use of one tool setup.

Why does tolerance matter when reaming a hole?

Tolerance refers to the permissible deviation from a specified dimension. In the context of reaming, it directly impacts the accuracy and functionality of the machined component.

Maintaining tight tolerances ensures that the finished holes align precisely with design specifications, promoting a proper fit and assembly of parts. Whether in aerospace, automotive, or general manufacturing, maintaining precise tolerances through reaming guarantees consistency in product quality, minimises the risk of defects, and improves overall performance.

What sizes and increments are reamers available in?

When it comes to reamers, a wide range of sizes and increments are readily available.

Reamers are manufactured in a variety of diameters, starting from as small as a 0.95mm and available in two decimal place increments, allowing machinists to choose the exact dimensions needed for creating precise holes.

Whether it's a fractional, decimal, or metric size requirement, reamers are designed to offer versatility and flexibility in accommodating various specifications.

At Cutwel we offer huge range of sizes and increments along with custom design service, if you require a reamer that’s not a stock item we can provide a special design service, please contact our technical team on 01924 860615 for more information.

What do I need to consider when choosing the right reamer?

When selecting a machine reamer for your application, several factors should be considered to ensure optimal performance and efficiency.

First and foremost, evaluate the material of the workpiece, as different reamer coatings and materials are better suited for specific materials.

Consider the desired hole size and tolerance requirements, as reamers come in various diameters and tolerances to meet precise specifications.

The type of reamer, such as straight flute, spiral flute, or modular, should be considered for the specific machining application and hole geometry.