Indexable Insert Drills

The term “U-drill” originally came from a specific product line by major brands such as Sandvik Coromant, whose early U-series drills later evolved into what is now known as the CoroDrill® 880 ,that its crossection resembles a U.Because of the strong market influence of this series, the name “U-drill” gradually became a general industry term für indexable insert drills.

It’s important to note that “U-drill” refers only to indexable insert drills, not to exchangeable-head drills. Those are typically called modular drills oder replaceable-tip drills, which are different in structure and application.

Yes, absolutely. U-drills can machine blind holes, but you must choose inserts designed specifically for blind-hole applications, such as SP-type (square) inserts.

However, keep in mind that the bottom of the hole will not be perfectly flat. Due to the geometry of the insert, the bottom typically forms a slight taper of around 7°.

This is usually a sign of tool vibration. You can address it by checking the following:

• Check rigidity: Ensure the toolholder, fixture, and workpiece are all clamped securely.

• Adjust cutting parameters: Slightly reduce the spindle speed or increase the feed rate (within the recommended range) to change the cutting harmonics.

• Shorten overhang: Use the shortest possible U-drill to minimize tool deflection.

• Inspect the inserts: Make sure the inserts are installed correctly and are not worn or damaged.

Absolutely — we do.

Sundi can fully support custom Indexable Insert Drill holder based on your machining requirements. Whether you need a special diameter, unique holder geometry, different coolant channels, or a non-standard insert seat design, our engineering team can design and manufacture the holder according to your drawings or application details.