Negative-rake woodturning inserts must match the toolhead as well as the material. The square and round picks below differ in dimensions, edge radius, angle, and pack size. Start with the exact seat on the existing tool.
Compare the 9 picks below by their dimensions, application, and compatibility. Match the configuration to your equipment and the job before comparing package quantity.
Quick Answer
- Best Overall: CDBP 11mm Negative Rake Carbide Inserts with 2" Radius — Square, 2-inch radius; 11 x 11 x 2 mm; 20°; 10 inserts.
- Best Ten-Piece Round Pack: CDBP 16mm Round Negative Rake Carbide Inserts — Round; 16 x 3 mm; 35°; 10 inserts.
- Best for Dense Blanks: CDBP 14mm Square Negative Rake Carbide Inserts — Square; 14 x 14 x 2 mm; 20°; 10 inserts.
Best Negative Rake Carbide Inserts for Woodturning Comparison Table
| Product | Best For | Key Specifications | Fit and Application |
|---|---|---|---|
| CDBP 11mm Negative Rake Carbide Inserts with 2" Radius | Overall | Square, 2-inch radius; 11 x 11 x 2 mm; 20°; 10 inserts | This is the sensible first pick for a compatible square roughing head and a turner who wants a useful reserve of cutters. Choose a round insert instead for hollowing work, or check the larger CDBP sizes if your toolhead requires a 14 mm or 15 mm cutter. |
| TANOMATE 16mm Negative Rake Round Ci0-NR Inserts | for Hollowing | Round; 16 x 3 mm; 35°; 10 inserts and screws | This is the better fit for a compatible full-size or PRO finisher and hollowing work in resin or acrylic. A smaller pack may suit occasional users, while the CDBP 16 mm round option provides the same listed diameter and thickness with a different specified rake specification. |
| CDBP 16mm Round Negative Rake Carbide Inserts | Ten-Piece Round Pack | Round; 16 x 3 mm; 35°; 10 inserts | Pick this pack if your holder already accepts the specified 16 mm round format and you want ten replacements. Buyers who need confirmed screws or a specified Ci0-NR fit may find the TANOMATE ten-piece pack easier to match. |
| TANOMATE 11x11mm-R50 Carbide Replacement Inserts | for Mini Tools | Square, R50 radius; 11 x 11 x 2 mm; Not specified; 10 inserts and screws | This pack makes the most sense for a mini roughing setup that already uses the R50-style size. It is less suitable for someone shopping by negative rake angle alone, since that specification is not provided in the product description. |
| CDBP 14mm Square Negative Rake Carbide Inserts | for Dense Blanks | Square; 14 x 14 x 2 mm; 20°; 10 inserts | Choose this insert only after confirming that your cutter head accepts the 14 mm format. It is a useful size-specific alternative for dense blanks, while the 11 mm CDBP has clearer compatibility information for EWT Ci2 roughers. |
| TANOMATE 16mm Round Ci0-NR Inserts, Three-Piece Pack | Compact Pack | Round; 16 x 3 mm; 30°; 3 inserts and screws | This is the pick for a buyer who needs a small, clearly specified round pack and does not want a large reserve. Choose the ten-piece version for frequent turning, or verify the exact rake requirement if your tool system calls for 35 degrees. |
| CDBP 15mm Square Negative Rake Carbide Inserts with 2" Radius | for EWT Roughers | Square, 2-inch radius; 15 x 15 x 2.5 mm; 20°; 10 inserts | This cutter suits an EWT rougher or another holder confirmed for the 15 mm format. For a smaller head, the CDBP 11 mm or TANOMATE 11 mm option is a safer direction because their dimensions are more compact. |
| TANOMATE 15x15mm-R50 Carbide Replacement Inserts | for Radius Shaping | Square, R50 radius; 15 x 15 x 2.5 mm; Not specified; 10 inserts and screws | This is a good fit for a turner whose holder is confirmed for the 15 mm R50 format and who values edge rotation. Buyers who need a specified 20-degree rake should choose one of the CDBP square products instead. |
| 12mm Round Negative Rake Carbide Inserts | Compact 12 mm Replacement Pack | 12 mm diameter; 2.5 mm thickness; negative-rake profile; 3 inserts | This is the practical low-quantity option for a compatible 12 mm round holder, especially if having a spanner in the package is useful. It is the wrong size for a 16 mm Ci0-NR tool, so compare the insert diameter before focusing on the smaller pack. |
1. CDBP 11mm Negative Rake Carbide Inserts with 2" Radius — Best Overall
The CDBP 11 mm square cutter is the clearest all-around match for turners who already use a compatible EWT Ci2 rougher. Its 11 x 11 x 2 mm dimensions, 20-degree negative rake, and 30-degree cutting angle are specified, so there is less guesswork than with a generic insert product description. The square profile and specified 2-inch radius also give it a shaping role beyond simple edge replacement, although the holder still determines whether that geometry is appropriate.
The product description identifies tungsten carbide construction and positions the inserts for resin, acrylic, and dense hardwood work. Those materials can be unforgiving at the edge, particularly when a blank contains hard transitions or embedded resin. A ten-piece plastic-box pack makes sense for a turner who goes through replacement cutters regularly or wants spares close by instead of stopping mid-project with a dull insert.
Pros
- specified 11 x 11 x 2 mm dimensions.
- Listed fit for EWT Ci2 roughers.
- 20-degree negative rake is specified.
- specified for resin, acrylic, and dense hardwoods.
- Includes 10 tungsten carbide inserts in a storage box.
Cons
- Compatibility is specifically described around EWT Ci2 roughers, so other holders need verification.
- Confirm the included hardware and use the toolhead’s required mounting screw.
This is the sensible first pick for a compatible square roughing head and a turner who wants a useful reserve of cutters. Choose a round insert instead for hollowing work, or check the larger CDBP sizes if your toolhead requires a 14 mm or 15 mm cutter.
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2. TANOMATE 16mm Negative Rake Round Ci0-NR Inserts — Best for Hollowing
Hollowing tools place a premium on controlled passes, and this TANOMATE round insert is specifically described for that job. The 16 mm diameter, 3 mm thickness, 30-degree cutting angle, and 35-degree negative rake give buyers concrete dimensions to compare with an existing Ci0-NR cutter head. The round edge suits a different motion from a square roughing insert, especially when the tool follows a curved interior.
Resin and acrylic are named applications, and the product description says the geometry is intended to reduce chipping and catches. Ten inserts arrive with screws in a plastic box, a practical arrangement for a dedicated hollowing setup where a replacement needs to be ready at the bench.
Pros
- 16 mm round profile is clearly identified.
- 3 mm thickness suits buyers seeking the specified Ci0-NR size.
- 35-degree negative rake is specified.
- product description identifies hollowing as an intended use.
- Includes 10 inserts and 10 screws.
Cons
- It is a specialized round insert, not a replacement for a square roughing cutter.
- Compatibility is described for full and PRO size finisher tools, so other holders require checking.
This is the better fit for a compatible full-size or PRO finisher and hollowing work in resin or acrylic. A smaller pack may suit occasional users, while the CDBP 16 mm round option provides the same listed diameter and thickness with a different specified rake specification.
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3. CDBP 16mm Round Negative Rake Carbide Inserts — Best Ten-Piece Round Pack
This CDBP cutter shares the useful 16 x 3 mm round format found in larger finisher tools, with a listed 35-degree negative rake and 30-degree cutting angle. That makes it an easy product to compare against other 16 mm round inserts, though the buyer still needs to match the screw and holder dimensions before ordering. For someone turning a steady stream of resin blanks or hardwood bowls, the ten-piece quantity keeps the replacement supply straightforward.
The product information identifies tungsten carbide and names resin, acrylic, and dense hardwoods. The round shape is especially relevant for curved work, where a square insert would present a different contact profile. A plastic storage box also keeps loose cutters from rattling around in a drawer beside sanding discs and small screws.
Pros
- specified 16 mm diameter and 3 mm thickness.
- 35-degree negative rake is specified.
- Round geometry suits compatible finisher-style tools.
- Listed for resin, acrylic, and dense hardwoods.
- included as a 10-piece tungsten carbide pack.
Cons
- Match the selected tool’s dimensions and mounting requirements to the job before ordering.
- Confirm the included hardware and use the toolhead’s required mounting screw.
Pick this pack if your holder already accepts the specified 16 mm round format and you want ten replacements. Buyers who need confirmed screws or a specified Ci0-NR fit may find the TANOMATE ten-piece pack easier to match.
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4. TANOMATE 11x11mm-R50 Carbide Replacement Inserts — Best for Mini Tools
Mini tools have less room for oversized cutters, which is where this 11 x 11 x 2 mm TANOMATE insert becomes interesting. The R50 radius provides a rounded cutting edge intended for some shaping and sweeping arcs, rather than limiting the insert to straight edge work. The product description specifically identifies mini rough woodturning and planing cutter heads, a useful clue for buyers comparing it with larger 14 mm and 15 mm options.
Pros
- Compact 11 x 11 x 2 mm format.
- R50 radius supports sweeping arc work.
- Listed for mini roughing and planing cutter heads.
- Includes matching screws according to the product description.
- Ten inserts arrive in a protective storage case.
Cons
- Match the negative-rake angle and countersink to the toolhead.
- The 11 mm format is not interchangeable with larger holders.
This pack makes the most sense for a mini roughing setup that already uses the R50-style size. It is less suitable for someone shopping by negative rake angle alone, since that specification is not provided in the product description.
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5. CDBP 14mm Square Negative Rake Carbide Inserts — Best for Dense Blanks
The 14 mm square CDBP inserts sit between compact 11 mm cutters and the larger 15 mm class. Their 14 x 14 x 2 mm dimensions and 20-degree negative rake are clearly listed, along with a 30-degree cutting angle. That middle size may appeal to a turner whose toolhead is built around a larger square cutter but does not accept the extra thickness of a 15 mm insert.
Resin, acrylic, hybrid blanks, and extremely dense hardwoods are the named applications. The product description also describes a 2-inch radius and tungsten carbide construction. In a drawer, the ten-piece pack is easy to separate from round inserts because the square outline is immediately visible, and the plastic box helps keep replacement edges organized.
Pros
- specified 14 x 14 x 2 mm dimensions.
- 20-degree negative rake is specified.
- Square profile with a listed 2-inch radius.
- Named for resin, acrylic, hybrid blanks, and dense hardwoods.
- Includes 10 inserts in a plastic storage box.
Cons
- Match the selected tool’s dimensions and mounting requirements to the job before ordering.
- Mounting screws are not listed among the included pack contents.
Choose this insert only after confirming that your cutter head accepts the 14 mm format. It is a useful size-specific alternative for dense blanks, while the 11 mm CDBP has clearer compatibility information for EWT Ci2 roughers.
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6. TANOMATE 16mm Round Ci0-NR Inserts, Three-Piece Pack — Best Compact Pack
A three-piece pack can be more sensible than ten replacements for an occasional turner or someone trying a compatible round cutter for the first time. This TANOMATE model uses the familiar 16 x 3 mm round format, but its listed negative rake is 30 degrees rather than the 35 degrees shown for the larger ten-piece Ci0-NR pack. That distinction is small on a product page and significant at the point of fit and geometry matching.
The product description names resin and acrylic, and it describes hollowing as an intended use. Three screws are included, with the product specifications identifying 5 x 8 mm, 90-degree screws. Those details make the pack more practical for a complete small replacement order, provided the holder accepts that exact insert and screw arrangement.
Pros
- 16 mm round, 3 mm thick format is specified.
- 30-degree negative rake is specified.
- Listed for hollowing, resin, and acrylic work.
- Includes three inserts and three screws.
- Compact quantity suits occasional replacement needs.
Cons
- Only three inserts are included.
- The listed rake angle differs from the 35-degree TANOMATE version, so the two should not be treated as identical.
This is the pick for a buyer who needs a small, clearly specified round pack and does not want a large reserve. Choose the ten-piece version for frequent turning, or verify the exact rake requirement if your tool system calls for 35 degrees.
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7. CDBP 15mm Square Negative Rake Carbide Inserts with 2" Radius — Best for EWT Roughers
The 15 mm CDBP square insert is aimed at a larger roughing-tool format, with 15 x 15 x 2.5 mm dimensions and a listed 20-degree negative rake. Its 2-inch radius adds a curved edge profile for shaping, while the 30-degree cutting angle keeps the specification distinct from the round products in this guide.
Resin, acrylic, and dense hardwoods are the specified applications, and the pack contains ten tungsten carbide cutters in a plastic box. That quantity works well for a busy turning routine, but the larger size and 2.5 mm thickness mean this is a poor substitute for an 11 mm or 14 mm holder. The physical match has to come before the attractive ten-pack count.
Pros
- 15 x 15 x 2.5 mm size is clearly listed.
- 20-degree negative rake is specified.
- 2-inch radius supports curved shaping work.
- Named for resin, acrylic, and dense hardwoods.
- Ten inserts are included in a storage box.
Cons
- The 15 mm size and 2.5 mm thickness restrict compatibility.
- Confirm the included hardware and use the toolhead’s required mounting screw.
This cutter suits an EWT rougher or another holder confirmed for the 15 mm format. For a smaller head, the CDBP 11 mm or TANOMATE 11 mm option is a safer direction because their dimensions are more compact.
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8. TANOMATE 15x15mm-R50 Carbide Replacement Inserts — Best for Radius Shaping
This TANOMATE cutter shares the larger 15 x 15 x 2.5 mm footprint with the CDBP option above, but its R50 designation and four usable edges give it a different maintenance story. When one edge becomes dull, the product description says the square cutter can be changed to another edge. That arrangement is useful during a long turning session when a quick rotation is preferable to opening a new insert.
The product description names spiral or helical planer cutter heads and lathe woodturning tools, so the application is broader in wording but also less specific to one woodturning holder. It identifies tungsten carbide with submicron-fine grain and includes ten inserts with screws in a plastic case. Buyers should treat the specified tool categories as a starting point and confirm the exact holder before ordering.
Pros
- specified 15 x 15 x 2.5 mm dimensions.
- R50 radius supports sweeping arc work.
- Each square cutter is listed with four sharp edges.
- Includes ten inserts and mounting screws.
- Named for spiral or helical planer heads and woodturning tools.
Cons
- Match the negative-rake angle to the woodturning holder.
- Confirm the exact woodturning seat, screw, and countersink.
This is a good fit for a turner whose holder is confirmed for the 15 mm R50 format and who values edge rotation. Buyers who need a specified 20-degree rake should choose one of the CDBP square products instead.
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9. 12mm Round Negative Rake Carbide Inserts — Best Compact 12 mm Replacement Pack
This compact replacement pack contains three 12 mm round negative-rake carbide inserts with a 2.5 mm thickness. The package also includes mounting accessories, making it an option for maintaining a holder that uses this exact round format.
Choose it by the seat diameter, thickness, countersink, and screw arrangement. A 12 mm cutter is not a substitute for the 16 mm round models here, and the angle should match the toolhead’s requirements. The smaller pack suits a single compatible tool without committing to ten cutters.
Pros
- 12 mm round profile.
- 2.5 mm thickness.
- Negative-rake edge format.
- Three-piece replacement pack.
- Mounting accessories included.
Cons
- Only fits the matching 12 mm tool seat.
- Confirm edge angle and screw fit before ordering.
This is the practical low-quantity option for a compatible 12 mm round holder, especially if having a spanner in the package is useful. It is the wrong size for a 16 mm Ci0-NR tool, so compare the insert diameter before focusing on the smaller pack.
To buy this product, click here.
Buying Guide
Full Cutter Fit
Compare outside size, thickness, center hole, countersink, and mounting screw. Matching outside dimensions alone do not prove tool compatibility.
The checklist for measuring a woodturning replacement insert covers thickness, mounting hole, and screw fit as well as outside size.
Edge Geometry
The CDBP square options specify 20-degree negative rake. The selected TANOMATE 16 mm ten- and three-packs specify different rake angles. Match the actual selected profile, including R2-inch or R50 mm edge radius.
Package and Hardware
Square roughers and round finishers are not interchangeable. Check whether screws are included and whether their thread and countersink suit the toolhead.
Frequently Asked Questions
Can 16 mm replace 12 mm?
Use only the cutter size and geometry required by the holder.
Are all rake angles identical?
No. Match angle and profile to the tool and intended work.
Will included screws always fit?
Confirm the tool’s required thread, length, and countersink.
Final Verdict
CDBP 11mm Negative Rake Carbide Inserts with 2" Radius is the starting point for buyers who need its configuration. This is the sensible first pick for a compatible square roughing head and a turner who wants a useful reserve of cutters. Choose a round insert instead for hollowing work, or check the larger CDBP sizes if your toolhead requires a 14 mm or 15 mm cutter.
For a different requirement, compare CDBP 16mm Round Negative Rake Carbide Inserts and 12mm Round Negative Rake Carbide Inserts. Compare outside size, thickness, center hole, countersink, and mounting screw. Matching outside dimensions alone do not prove tool compatibility.
