The Basics of Reamers
Reamers are cutting tools that are used to remove a small amount of material from previously drilled holes to ensure dimensional accuracy and a smooth surface finish. They are commonly used in metalworking industries as well as in woodworking and plastic manufacturing applications. Reamers are available in different types and forms, including spiral flute and straight flute reamers. This article will focus on the differences between straight flute and spiral flute reamers.
Straight Flute Reamers
Straight flute reamers (also known as hand reamers) have a linear arrangement of teeth that run parallel to the axis of the tool. They are preferred for softer materials such as aluminum and brass and are suitable for manual operations. These tools are often used for reaming holes that require tight tolerances and a smooth finish. Due to their design, straight flute reamers have a limited chip evacuation ability, and they are more susceptible to chatter during machining operations.
Spiral Flute Reamers
Spiral flute reamers have helical channels that spiral around the axis of the tool. The helix angle determines the rate at which the chip is evacuated from the hole. These types of reamers are ideal for removing material from harder materials, such as steel and cast iron. The spiral design allows for a better chip evacuation, reducing the chances of chip buildup, which can lead to tool damage and an undesirable surface finish. Spiral flute reamers are suitable for use with both manual and CNC operations.
When to Use a Straight Flute Reamer
Straight flute reamers are ideal for use when the material being machined is softer and manual drilling operations are preferred. They are commonly used in maintenance and repair operations, where drilling is done by hand. The linearly aligned teeth make them suitable for reaming holes that require a smooth finish and close tolerances. Straight flute reamers are also less expensive than spiral flute reamers, making them an economical choice for smaller operations.
When to Use a Spiral Flute Reamer
Spiral flute reamers are the tool of choice when working on harder materials, both manually and with CNC machines. The design allows for faster and more efficient chip evacuation, which is necessary when machining materials such as steel and cast iron. Additionally, the spiral arrangement of teeth mitigates chatter during machining operations leading to a better surface finish. While spiral flute reamers are more expensive than their straight flute counterparts, they offer better performance and longer tool life.
Both spiral flute and straight flute reamers have their advantages and disadvantages depending on the job at hand. Straight flute reamers are ideal for use on softer materials and manual drilling operations, while spiral flute reamers are ideal for harder materials and CNC machining operations. Choosing the right type of reamer will depend on the material being machined, the procedure being used, and the desired quality of the finished product.