The Benchmark Abrasives SN-4 Inverted Cone Premium Tungsten Carbide Burr is built for fabricators, machinists, welders, and metalworkers who expect professional-grade cutting performance and dependable construction. 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 made for demanding deburring, shaping, contouring, and material-removal applications.
The SN-4 combines that premium construction with a larger 1/2" inverted-cone profile and double-cut tooth pattern for controlled work on undercuts and reverse-angle contours. Its head widens away from the shank, creating a broad cutting surface that can work behind edges, beneath lips, and across recessed geometry that conventional cone or cylinder profiles cannot approach as effectively. The intersecting double-cut flutes divide removed material into smaller chips, providing a more manageable cutting action and smoother result than a comparable single-cut burr while still removing material aggressively.
Whether you're enlarging or refining undercuts, cleaning reverse-angle features, deburring recessed edges, or performing general fabrication and maintenance work, the SN-4 provides substantially more cutting surface than the smaller SN-1 while retaining the specialized geometry of an inverted cone. The 1/4" shank fits compatible die grinders and rotary tools with a matching collet, while the standard-length 1/2" head is rated for a maximum speed of 50,000 RPM.
Features
- Premium tungsten carbide construction
- Double-cut design for efficient, controlled stock removal
- 1/2" inverted-cone profile for broader undercuts and reverse-angle contours
- Broad cutting surface for medium localized material removal
- Geometry designed to reach behind edges and into recessed features
- Produces smaller chips than comparable single-cut burrs
- Suitable for deburring, shaping, contouring, and localized stock removal
- 1/4" shank for compatible die grinders
- Sold individually
Applications
The SN-4 inverted-cone profile is well suited for:
- Undercut shaping
- Reverse-angle contours
- Recessed edge cleanup
- Working beneath lips and overhangs
- Internal contouring
- Deburring machined and fabricated parts
- Medium localized stock removal
- General fabrication and maintenance work
Materials
Recommended primarily for:
- Steel
- Stainless steel
- Cast iron
Also suitable for additional materials when the correct operating speed and technique are used, including titanium, nickel, wrought iron, copper, fiberglass, plastic, hard rubber, wood, and stone.
Machine Compatibility
Designed for die grinders and other rotary tools equipped with a properly sized 1/4" collet.
Compatible examples include:
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Benchmark Straight Pneumatic Die Grinder (BMT-DGST_1) — 1/4" collet, up to 25,000 RPM.
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DEWALT DCG426B — 1/4" collet, variable speed up to 25,000 RPM.
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Milwaukee 3485-20 — 1/4" collet, variable speed up to 20,000 RPM.
Always confirm the burr shank is securely seated in the correct collet and that the machine speed is appropriate for the burr diameter, workpiece material, and application.
Cutting Performance
The SN-4 inverted-cone shape widens away from the shank, giving it a cutting profile specifically suited for undercuts and reverse-angle contours. Its 1/2" head and 1/2" cut length provide substantially more cutting surface than the SN-1, making it better suited for broader recessed areas and medium stock removal while retaining access behind edges and beneath lips.
The double-cut pattern divides removed material into smaller chips, helping provide controlled stock removal and a smoother working feel than a comparable single-cut burr. 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 as a starting guide to operating speed based on the 1/2" burr head diameter and workpiece material. These are suggested cutting ranges, not minimum machine speeds; conventional die grinders commonly run at 20,000–29,000 RPM.
Do not exceed the 50,000 RPM maximum speed for this standard-length 1/2" carbide burr. Always operate within the lower maximum speed of the burr, machine, collet, or accessory system.
Safety Tips
- Always wear appropriate eye, hearing, respiratory, and hand protection.
- Secure the workpiece before beginning operation.
- Confirm the 1/4" shank is properly seated and securely tightened in the correct collet.
- 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.
- Use additional care when working behind edges or in undercut areas where visibility may be limited.
- 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 50,000 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.
