0.0551" (1.40mm) × .275" LOC Diamond Flute PCB Router, Drill Point, 1/8" Shank | R128

Kyocera 1.40mm Diamond-Flute PCB Router | .275" LOC | Drill Point | Up-Cut

The R128 solid carbide diamond-flute router features a 0.0551" (1.40mm nominal) cutting diameter, 0.275" (approximately 7.00mm) length of cut, and standard 1/8" (3.175mm) shank. Manufactured by Kyocera, this precision router is designed for machining FR4/G10 printed circuit board laminates, fiberglass, phenolic materials, and other abrasive composites.

Its diamond-pattern cutting geometry uses numerous small, intersecting cutting edges for controlled material removal. The drill-point tip supports direct plunge entry under suitable cutting conditions, while the .275" cutting length provides reach for PCB profiling, slots, and internal cutouts.

Key Features

• 0.0551" (1.40mm) cutting diameter: Precision cutting width for PCB outlines, slots, and contours
• 0.275" LOC: Approximately 7.00mm of cutting length for suitable laminate and composite workpieces
• Diamond-flute geometry: Multiple intersecting cutting edges help control chipping, fraying, and fiber pull-out under appropriate machining conditions
• Drill-point tip: Designed to facilitate plunge entry for internal cutouts and slots in suitable materials
• Up-cut configuration: Promotes upward chip and debris evacuation during routing
• Solid tungsten carbide: Provides rigidity and resistance to abrasive wear
• 1/8" shank: Fits compatible precision CNC spindle collets and tool holders

Diamond-Flute Geometry & Drill-Point Tip

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

The drill-point tip provides a pointed end-cutting geometry intended to facilitate entry into suitable workpieces. It is useful when starting slots, internal contours, and cutouts where a separate entry hole may not be practical.

Plunge performance, edge finish, and tool life depend on material, spindle speed, feed rate, machine rigidity, and workholding. A drill-point tip should not be interpreted as permitting aggressive or unrestricted plunge cutting.

0.275" Cutting Length

R128 provides 0.275" (6.985mm) of cutting length. Select a cutting length appropriate for the material thickness and provide sufficient clearance beneath the workpiece when through-cutting.

As with other small-diameter carbide routers, excessive side loading or unsupported cutting length can increase the risk of deflection and breakage.

Important: Diamond-flute refers to the cutting-edge geometry. R128 is uncoated solid carbide, not diamond-coated or PCD tooling.

Typical Applications

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

Technical Specifications

Feeds & Speeds

Proper spindle speed, feed rate, cutting depth, and secure workholding are important when machining fiberglass-reinforced PCB laminates with carbide routers.

View Diamond-Flute Router Feed & Speed Chart for general starting recommendations when routing FR4, G10, fiberglass, and other PCB materials.

Recommended cutting parameters are starting points only. Adjust for the material, machine rigidity, spindle capability, tool condition, workholding, and cutting depth. Avoid excessive cutting loads and use appropriate dust extraction when machining fiberglass or carbon fiber.

Related Router Bits & Guides

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Diamond-Flute Router Guide
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