MITGI Reamers

Precision manufacturers rely on reamers to bring holes to their finished size, achieve smooth surface finishes, and stay within extremely tight tolerances. In finishing applications, the tools must achieve intended results – otherwise, all of the work that precedes it will have been wasted. In industries like medical device manufacturing, aerospace, automotive, and defense, the end mills used in production must be designed to achieve part specs, including tight tolerances. MITGI has built its business around the idea that customers need precision tools, tight tolerances, short lead times, and predictable delivery schedules. Whether you need a quick turn, blanket pricing, or want to work with us on a continuous improvement project, MITGI has you covered.

MITGI standard reamers are available in both inch and metric sizes. With 8X flute length and an optional 12X reach, MITGI standard reamers are a good general-purpose option to consider when lead times are especially short.

MITGI standard reamers are made to tight tolerances (+0.0002 in., and +0.005mm). In custom sizes, tighter tolerances may be available, depending on tool specs. Contact us to discuss the requirements to achieve your specific application.

MITGI standard tools are straight flute with a slightly chamfered end. When developing custom tools, customers often move to spiral flute (RH for blind holes, LH for thru-holes). Many custom tools may utilize a ball or radius end finish to create smooth, rounded blind holes.

Although 4-flute reamers are the most commonly used, MITGI also offers 2- and 3-flute options as standard and custom tools.

FAQs

How do you decide whether to use a standard tool or move to a custom?
There are several answers to this seemingly simple question. For example:
- Lead time may be a deciding factor. Our regular lead time for standard tools is 3 days or less, while custom tools are usually available in 2 weeks or less. Regardless of how we quote a tool in normal circumstances, we understand when companies are pressed for time. We don’t charge to expedite, but we will try to accommodate schedules whenever possible. Let us know what you need and we’ll do our best to achieve it.
- Production volume may drive your decision. If you are a high-mix, low-volume facility, a standard tool may be a great option for you. A MITGI standard tool will help achieve tight tolerances and great surface finish and can be used in a variety of materials and projects. If you are a high-volume, low-mix facility, custom tools may be worth considering. When production lines are tasked with increasing tool life, improving cycle times, or increasing throughput, custom tools may help to achieve the goals through application-specific features and geometries.
- Not sure? Just ask. Send us your tool specs, info on the project, and any goals you’re trying to achieve. If a standard tool exists, we’ll let you know. If we see any opportunities for improved performance by moving to a custom, we’ll give you the option to consider.
When reaming a blind hole, what should be considered?

Drilling and reaming blind holes have its own set of challenges, all of which tie to chip evacuation. With a thru-hole, chips exit out the bottom of the hole, keeping the hole clear of debris. In a blind hole where the only exit is the entrance, chips can wrap, pack, nest, or be re-cut – all of which create problems like tool breakage, poor surface finish, and low tool life. The best thing you can do to avoid these situations is to let us know that you’re drilling and/or reaming a blind hole. With this information, we can design the tool to include a right-hand spiral, which pulls the chips upward instead of pushing the chips back into the hole.
When reaming a thru-hole, what do I need to know?

Whether making a thru-hole or a blind hole, the most important thing is to get the chips out of the way. With a thru-hole, pushing the material out is made easier by using a left-hand spiral and/or coolant to flush out the hole. Coolant thru material may be utilized (holes through the tip, out the shoulder, or coolant channels), or coolant may be moved through the flutes. When designing a custom reamer, be sure to let us know you’re making a thru-hole so we can apply a geometry that will aid chip removal.
What are common tolerances on MITGI reamers?
What are the advantages of a step reamer?
How do you determine what cutting diameter size you need when choosing a drill and reamer?

When making holes, drill cutter diameters should be sized slightly smaller than the requirements for the finished hole. By selecting an undersized drill, a small amount of material will be left behind, which will be removed by the reamer in the finishing pass. Using this logic, select an undersized drill diameter (actual amount will vary based on final hole size and material) and a reamer size that matches the requirements of the finished hole.
How can you extend the life of a reamer?

If your reamer is working well, but you’d like it to last longer, coating is often a good place to start. It may not be suitable for every material, but the added lubricity and heat control that the coating provides may help to extend tool life. If your tool is already coated, it may be worth considering switching to a different coating. There may be more than one coating that is suitable for a material, and upgrading to a higher-performance coating may help extend life in applications that produce more heat. Learn more about our in-house coating options.

In some cases, tool geometry changes may help to increase the life or improve the performance of a reamer. Edge prep, flute polishing, or clearance angle changes may help provide smoother surfaces while maintaining critical dimensions.

MITGI Custom Tools

In applications where the part is very complex, it’s for a high-volume product, or when it uses a hard-to-machine material, a custom tool may be the preferred option. Custom tools provide manufacturers with the ability to achieve specialized features, geometries designed for specific materials, and to achieve tool life or surface finish goals. Count on MITGI to provide accurate custom tools, achieve tight tolerances, and are usually available in two weeks or less.

Getting started is easy. Contact us to discuss your custom tool request. Or, complete a tool quote sheet and send it our way. We’ll review the information, connect with you regarding any questions we may have, and send a quote to you promptly.

MITGI Reamers

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FAQs

How do you decide whether to use a standard tool or move to a custom?

When reaming a blind hole, what should be considered?

When reaming a thru-hole, what do I need to know?

What are common tolerances on MITGI reamers?

What are the advantages of a step reamer?

How do you determine what cutting diameter size you need when choosing a drill and reamer?

How can you extend the life of a reamer?

MITGI Custom Tools

Quote Sheets

Reamers

Step Reamers

MITGI Standard Tools

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Metric Reamers