0.0500" (1.27mm) × .276" LOC Diamond Flute PCB Router, Fish Tail, 1/8" Shank | R121

Kyocera 1.27mm Diamond-Flute PCB Router | .276" LOC | Fish Tail | Up-Cut

The R121 solid carbide diamond-flute router features a 0.0500" (1.27mm) cutting diameter, 0.276" (7.00mm nominal) length of cut, and standard 1/8" (3.175mm) shank. Manufactured by Kyocera, this precision router is designed for PCB profiling, FR4/G10 fiberglass laminates, phenolics, and other abrasive composite materials.

Its diamond-pattern cutting geometry uses numerous small, intersecting cutting edges for controlled material removal. The fishtail tip provides end-cutting capability for suitable sheet materials, while the 0.276" LOC offers additional cutting reach compared with shorter routers of the same diameter.

Key Features

• 0.0500" (1.27mm) cutting diameter: Precision cutting width for PCB board outlines, slots, and contours
• 0.276" (7.00mm nominal) LOC: Useful cutting reach for suitable PCB laminates and composite sheets
• Diamond-flute geometry: Multiple intersecting cutting edges help control fraying, chipping, and fiber pull-out under appropriate cutting conditions
• Fish tail tip: End-cutting geometry supports entry and through-routing in suitable sheet materials
• Up-cut configuration: Helps direct chips and routing debris upward
• Solid tungsten carbide: Provides rigidity and resistance to abrasive wear
• 1/8" shank: Fits properly sized precision CNC collets and tool holders

Diamond-Flute Geometry & Fish Tail Tip

Diamond-flute routers, also called diamond-cut or diamond-pattern routers, feature numerous intersecting cutting edges rather than conventional continuous spiral flutes. This geometry is widely used for machining abrasive, brittle, and layered materials such as FR4 circuit boards and G10 fiberglass laminates.

The fishtail tip has cutting edges at the tool end, supporting plunge entry into suitable workpieces and through-routing operations. Properly selected cutting parameters and secure workholding can help limit edge damage and backside breakout when machining reinforced laminates.

The 0.276" cutting length provides approximately 7.00mm of usable flute length. For through-cutting, ensure the flute length is appropriate for the workpiece thickness and provide adequate clearance below the material.

Important: Diamond-flute describes the cutting-edge geometry. R121 is uncoated solid carbide, not diamond-coated or PCD tooling.

Typical Applications

• PCB board outlines, slots, and cutouts
• FR4 and G10 fiberglass laminate routing
• Phenolic and epoxy laminate cutting
• Fiberglass-reinforced composite trimming
• Carbon fiber composites where uncoated carbide tooling is suitable
• Precision CNC profiling, prototyping, and small-part fabrication

Technical Specifications

Feeds & Speeds

Correct spindle speed, feed rate, depth of cut, and secure workholding are important when routing PCB laminates and abrasive composites with small-diameter carbide tooling.

View Diamond-Flute Router Feed & Speed Resources and select the dedicated Diamond-Flute Router Chart for FR4, G10, fiberglass, and PCB laminates.

Cutting recommendations are starting points only. Adjust for the material, spindle capability, machine rigidity, tool condition, and workholding. Test on scrap material, avoid excessive cutting loads, and use appropriate dust extraction when machining fiberglass or carbon fiber.

Related Router Bits & Guides

Shop Diamond-Flute PCB Router Bits
Browse additional diameters, flute lengths, and plunge-tip configurations.

Diamond-Flute Router Guide
Learn about diamond-cut geometry, fishtail and drill-point tips, and selecting the appropriate router for PCB laminates and composites.

Comparing 0.0500" routers? R122A offers the same 1.27mm diameter with a shorter 0.250" fishtail cutting length, while R124 offers a 0.275" LOC with a drill-point tip.