Product Specification
SN-51NF INVERTED CONE ALUMA CUT CARBIDE BURR – 1/8" SHANK
The Benchmark Abrasives SN-51NF inverted cone premium tungsten carbide burr is built for fabricators, machinists, metalworkers, and detail-oriented users who need controlled cutting performance on aluminum and other soft nonferrous materials in undercuts, reverse angles, and recessed features. Unlike lower quality burrs that may use hollow heads or inconsistent brazing, Benchmark carbide burrs feature a solid carbide head with a silver-brazed connection to the shank. The result is a strong, stable cutting tool designed for precise deburring, shaping, contouring, and specialized material removal.
The SN-51NF combines that premium construction with a compact 1/4" inverted-cone profile and Aluma Cut tooth geometry. Its head widens away from the shank, creating a reverse-angle cutting profile that is especially useful for undercuts, back-side features, recessed shoulders, and contours that cannot be reached effectively with a conventional cone or cylinder shape. The wider, more open tooth spacing provides improved chip clearance on aluminum and other soft nonferrous materials to help reduce chip packing during cutting.
Its 1/8" shank makes the SN-51NF well suited for compatible rotary tools and precision grinders equipped with the correct 1/8" collet or chuck. The compact inverted-cone head provides specialized access for detailed work, while the standard-length 1/4" head is rated for a maximum speed of 70,000 RPM.
Product Specifications
| Specification |
Details |
| Product Code |
SN-51NF |
| Burr Material |
Tungsten Carbide |
| Head Shape |
Inverted Cone |
| Cut |
Aluma Cut |
| Head Diameter |
1/4" |
| Cut Length |
1/4" |
| Shank Diameter |
1/8" |
| Overall Length |
1-3/4" |
| Max RPM |
70,000 RPM |
| Quantity |
1 Piece |
Features
- Premium tungsten carbide construction
- Aluma Cut tooth geometry for improved chip clearance
- Open tooth spacing suited for aluminum and soft nonferrous materials
- Inverted-cone profile for undercuts and reverse-angle contours
- Compact 1/4" head for detailed and recessed work
- Specialized geometry for back-side and undercut access
- 1/8" shank for compatible rotary tools and precision grinders
- Suitable for deburring, shaping, contouring, and localized stock removal
- Sold individually
Applications
The SN-51NF inverted-cone profile is well suited for:
- Undercuts
- Reverse-angle contours
- Recessed shoulders
- Back-side feature shaping
- Internal edge cleanup
- Deburring aluminum components
- Specialized contouring
- Localized stock removal
- General nonferrous fabrication and maintenance work
Materials
The Aluma Cut tooth pattern is intended primarily for:
- Aluminum
- Other soft nonferrous materials
Its wider, more open tooth spacing is designed to provide better chip clearance on softer materials where closely spaced cutting teeth can be more prone to loading.
Machine Compatibility
Designed for rotary tools, precision grinders, and other compatible machines equipped with a properly sized 1/8" collet or chuck.
Compatible examples include Dremel® 4300, 4000, and 3000 fitted with a Dremel 480 1/8" collet and matching collet nut. The 4300 can also hold the 1/8" shank in its keyless chuck.
Always confirm the 1/8" shank is securely seated in the correct collet or chuck before operation. A 1/8" shank is not interchangeable with 3 mm tooling.
Cutting Performance
The SN-51NF inverted-cone shape provides a reverse-angle cutting profile that widens away from the shank, allowing the burr to reach under edges and into contours that are difficult to access with standard cone, cylinder, or tree shapes. This makes it especially useful for undercuts, recessed shoulders, back-side features, and reverse-angle geometry.
Because the inverted cone requires clearance around the wider cutting head, it is best used where the workpiece geometry allows the burr to enter and move safely within the feature. The Aluma Cut tooth pattern uses wider, more open spacing than a double-cut pattern to provide additional room for chips to clear during cutting on aluminum and other soft nonferrous materials.
Carbide burrs are primarily cutting and shaping tools; applications requiring a refined cosmetic finish should be followed with the appropriate abrasive finishing process.
Use the chart above to select the recommended operating-speed range based on the 1/4" burr head diameter and workpiece material.
Do not exceed the 70,000 RPM maximum speed for this standard-length 1/4" carbide burr. Always operate within the lower maximum speed of the burr, machine, collet, chuck, or accessory system.
Safety Tips
-
- Secure the workpiece before beginning operation.
- Confirm the 1/8" shank is properly seated and securely tightened in the correct collet or chuck.
- Confirm there is sufficient clearance for the inverted-cone head before entering a recessed or undercut feature.
- Use light, controlled pressure and allow the carbide cutting edges to remove the material.
- Keep the burr moving during cutting rather than holding it stationary against the workpiece.
- Avoid excessive force, which can increase heat, vibration, and premature cutting-edge wear.
- Select operating speed according to burr diameter, workpiece material, machine requirements, and the recommended operating-speed chart.
- Never exceed 70,000 RPM.
- Stop immediately if excessive vibration, chatter, unusual noise, or visible damage occurs.
- Do not use a damaged, chipped, bent, or improperly mounted carbide burr.
