Dapra's Toroid Line includes four high-performance inserts, including our new RHINO-CARB™ line, to maximize the versatility of our Toroid cutting tools:

Match the insert R value to the designation on your cutter body.
‡ Fits 1-1/4" diameter and above only.
| Cutting Edge | Edge Strength | Tool Pressure | Heat Creation |
|---|---|---|---|
| T (T-Land) | Strongest | Highest | Highest |
| N (Neutral) | Strong | Medium | Medium |
| D (Dished) | Medium | Lowest | Lowest |
![]() | Use Dapra's "T" geometry where the heaviest cuts are taken, or where vibration or chatter may be causing edge damage. This geometry is suitable for steels, irons and 400-series stainless. |
![]() | Use Dapra's "N" geometry in typical cutting applications where high-performance milling of steels, irons and 400-series stainless is desired. Available for round and octagonal RHINO-CARB inserts only. |
![]() | Use Dapra's D geometry in applications where the lowest tool pressure and higher shear are required. This geometry is best for most stainless steels and high-temperature alloys, but it is also a very free-cutting performer in softer steels. |

Dapra's RHINO-CARB™ high-performance inserts are designed for very aggressive metal cutting and long tool life.
Important: These thicker pressed inserts may cause your cutter to cut a slightly larger diameter than with ground inserts. Always measure tool diameter before use. RHINO-CARB inserts also require a thicker top clamp than ground inserts.
New inserts fit current Toroid end mills and shell mills but require a thicker top clamp.*

Round inserts have a strong cutting edge, making them an excellent choice for many button cutter applications, including:
Follow these links to view the Button Inserts that are available for each R/IC value:
Click here for technical help on optimum feeds for button inserts.
(R4 is 1-1/4" dia. and above only)
Ultra-aggressive geometry takes advantage of chip thinning to allow feed rates up to 4x faster than normal! Use high-feed inserts for:
Follow these links to view the High-Feed Inserts that are available for each R/IC value:
Click here for technical help on feed compensation for high-feed inserts.

** High-feed inserts require a specific program radius in order to provide correct material removal and avoid undercutting.
(1-1/4" dia. and above only)
Your Toroid cutter can now be used for the most common applications involving 90° milling. Utilize the more economical 4-sided inserts for:
Follow these links to view the Square Inserts that are available for each R/IC value:
8-sided geometry is excellent for general face milling. 45° lead angle provides increased feed capacity for:
Each of the 8 usable edges comes with an integral wiper flat for outstanding surface finishes.
Click here for information regarding 45° lead angle compensation for octagonal inserts.
* R4 Octagonal available in RHINO-CARB style only.
| Shock & Wear Resistance | Uncoated (Base Grade) | with Coating | Description | Specifications |
|---|---|---|---|---|
| TOUGHEST Shock Resistance |
DMK30 | Moderate wear resistance/high shock resistance. Recommended for interrupted or unstable steel, most 300 series stainless steel, high-temperature alloys and cast iron applications. | ANSI C1-C2, ISO K25-K40, M25-M35 | |
| DMK303 | PVD TiCN coating. Excellent wear resistance for low-to-medium operating temperatures. | |||
| DMK30-HP | High-performance medium-temperature grade. Optimum performance and wear resistance in most soft steels, soft stainless steels and cast irons. | |||
| DMK307 | PVD AlTiN coating. For higher-temperature applications including tougher stainless steels, high-temperature alloys and soft tool steels. | |||
| DMK30-GLH | Premium high-temperature coating. Best resistance to heat for high-shock applications. Excellent for tough stainless steels, high-temperature alloys and soft tool steels. | |||
| MEDIUM Shock and Wear |
DMK25† | Micro-grain carbide providing higher wear resistance and good shock resistance for applications in tough stainless steels, high-temperature alloys, irons and many tool steels. | ANSI C2-C3, ISO K15-K30, M15-M30 | |
| DMK253 | PVD TiCN coating. Excellent wear resistance for low-to-medium operating temperatures. | |||
| DMK25-HP | High-performance medium-temperature grade. Optimum performance and wear resistance in most soft steels, soft stainless steels and cast irons. | |||
| DMK257 | PVD AlTiN coating. For higher-temperature applications including high-speed machining and heat-treated materials < 44 Rc. | |||
| DMK25-GLH | Premium high-temperature coating. Outstanding performance and wear resistance in high-heat applications involving tough stainless steels, high-temperature alloys and many tool steels. | |||
| MEDIUM Shock and Wear |
DMP25 | High wear resistance/moderate shock resistance, recommended for most steel and 400 series stainless steel applications. | ANSI C5-C6, ISO P25-P40 | |
| DMP253 | PVD TiCN coating. Excellent wear resistance for low-to-medium operating temperatures. | |||
| DMP25-HP | High-performance medium-temperature grade. Optimum performance and wear resistance in most soft steels, soft stainless steels and cast irons. | |||
| DMP257 | PVD AlTiN coating. For higher-temperature applications including high-speed machining and heat-treated materials < 44 Rc. | |||
| DMP25-GLH | Premium high-temperature grade. Unbeatable performance and wear resistance in high-heat applications such as higher speed machining in steels (<44 Rc) and ductile irons. | |||
| HARDEST Wear Resistance |
DMK15 | Highest wear resistance with reduced shock absorption capabilities. Micro-grain carbide provides excellent edge strength for abrasive applications in nonferrous materials. Suitable for castings, aluminum and smoother cuts in tough stainless steels, high-temperature alloys and hardened steel. | ANSI C2-C3, ISO K15-K25, M15-M25 | |
| DMK153 | PVD TiCN coating. Excellent wear resistance for low-to-medium operating temperatures. Good resistance to built-up edge for aluminum machining. | |||
| DMK15-HP | High-performance medium-temperature grade. Optimum performance and wear resistance in most soft steels, soft stainless steels and cast irons. | |||
| DMK157 | PVD AlTiN coating. Appropriate for higher-temperature applications such as high-velocity cast iron machining, tough stainless steels, high-temperature alloys and hardened steel. | |||
| DMK15-GLH | Premium high-temperature grade. Unbeatable performance and wear resistance in high-heat applications such as harder steels, tough stainless steels and high-temperature alloys. |
DMK30-HP is a good first choice for most applications. Additional coatings available on request. Contact Dapra for details.
† DMK25 substrate is available for RHINO-CARB D and N geometries only.
Dapra Toroid products are made in the USA.