Left hand rotation spiral bits provide a shear cutting edge that leaves a smoother cut than standard router bits. Up cut spiral design provides the best control with hand or table routing. When creating dado’s this design brings chips up and out of the cut.

TOOL SPECS: Solid carbide, up cut, left hand spiral with 3/8″ cutting diameter, 3/8″ shank, 1″ cutting length, and 3″ overall length for use in routers with a 3/8″ collet.
LEFT HAND: Compatible with routers that feature dedicated left-hand rotation for precise and efficient cutting.
UP CUT SPIRAL: Ideal for smooth finishes and rapid chip removal. Up cut spirals create a clean edge on the side of the material that is farthest from the router.
HELIX: The upward cutting action removes chips efficiently, especially in deep cuts. The spiral helix ensures clean, crisp cuts while outperforming standard straight bits.
MULTI-PURPOSE TOOLING: Plunge-capable bit for precision woodworking. Perfect for creating grooves, dados, slots, pockets, and more.
MATERIALS: Performs best with hardwoods, softwoods, plywood, MDF, and hard plastics for versatile woodworking applications. Compatible with hand-held routers, table routers, and CNC machines.

Whiteside catalog page 5.

Part No.	LU4100
Series	Left Hand Up Cut Spiral
Description	Left Hand Up Cut Spiral, 3/8" Shank, 3/8" Dia, 1" CL, 3" OAL
Shank	3/8"
Cutting Diameter	3/8"
Cutting Length	1"
Overall Length	3"
Profile	Up Cut
Materials	Natural woods, composites, hard plastics, thin aluminum
Recommended RPM	16,000-18,000 (max 24,000)

Part No.	Shank	Cutting Diameter	Cutting Length	Overall Length	Profile	Price
LU1600	1/4"	1/8"	1/2"	2"	Up Cut	$33.44 Add to cart
LU1800	1/4"	3/16"	3/4"	2-1/2"	Up Cut	$33.44 Add to cart
LU2100	1/4"	1/4"	1"	2-1/2"	Up Cut	$31.61 Add to cart
LU3100	5/16"	5/16"	1"	3"	Up Cut	$58.62 Add to cart
LU4100	3/8"	3/8"	1"	3"	Up Cut	$63.72 Add to cart
LU5125	1/2"	1/2"	1-1/4"	3"	Up Cut	$85.11 Add to cart
LU5200	1/2"	1/2"	2"	4"	Up Cut	$114.30 Add to cart
LU6200	5/8"	5/8"	2"	4"	Up Cut	$265.14 Add to cart
LU7200	3/4"	3/4"	2"	4"	Up Cut	$212.84 Add to cart

Brand

Whiteside

Need This Tool Customized?

Every machining application is different. If this tool is close to what you need but not an exact fit, General Cutting Tools can help modify it for your specific job, machine, material, or production requirement.

We work with CNC shops, industrial manufacturers, tool rooms, and production facilities to provide tool modifications that improve fit, function, performance, and efficiency. Whether you need a small adjustment or a more specialized cutting tool solution, our team can review your requirements and recommend the best option.

Custom tool modifications can help reduce setup time, improve accuracy, extend tool life, solve clearance issues, and support more consistent production results.

Common Tool Customization Options

Diameter and OD Modifications

We can modify tool diameters to better match your application requirements, including cutting diameter changes, OD modifications, pilot diameter adjustments, step diameters, and shank diameter modifications.

Bore Modifications for Saw Blades

Custom saw blade bore modifications are available for hole diameter changes, pinholes, mounting holes, and keyway cutouts to help match your machine setup and cutting requirements.

Length Adjustments

Tools can be modified for specific reach, clearance, or setup needs. This may include overall length changes, flute length adjustments, reduced neck sections, extended reach designs, or shortened tools for improved rigidity.

Shank Modifications

Shank modifications can help ensure the tool fits properly in your holder, spindle, or machine setup. Common options include shank diameter changes, flats, Weldon flats, reduced shanks, and custom holding requirements.

Radius, Chamfer, and Corner Changes

We can customize corner radius, chamfer angles, edge breaks, and other profile details to meet part print requirements or improve cutting performance.

Step Tool Modifications

For applications that require multiple diameters or operations in a single tool, we can create or modify step tools to help reduce tool changes and improve production efficiency.

Flute and Cutting Edge Adjustments

Depending on the tool and application, flute length, cutting edge geometry, end cutting features, relief angles, and cutting edge shape may be modified to improve chip evacuation, cutting action, and tool performance.

Regrinding and Resharpening

Many cutting tools can be reground or resharpened to restore performance, extend tool life, and reduce replacement costs.

Custom Profiles and Special Forms

For unique part features, we can help provide special forms, custom profiles, custom radii, counterbores, countersinks, keyseat cutters, form tools, and other application-specific tooling solutions.

Material-Specific Tool Adjustments

We can help modify or recommend tooling based on the material being machined, including aluminum, brass, bronze, plastics, stainless steel, hardened steel, cast iron, composites, and other industrial materials.

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Send us your print, sketch, CAD file, photo, tool number, sample, or application details. For the fastest quote, include the material being cut, quantity needed, required dimensions, tolerances, and any machine or holder requirements.

Coating Options

Tool coatings can be selected or added to improve wear resistance, heat resistance, lubricity, and performance in specific materials such as steel, stainless steel, aluminum, cast iron, and high-temperature alloys.

Request a Custom Tool Modification

Need this tool changed for your application? Contact General Cutting Tools today to discuss your custom tooling needs. We can help you find the right solution for your machine, material, and production goals.

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Whiteside LU4100 Left Hand Up Cut Spiral, 3/8″ Shank, 3/8″ Dia, 1″ CL, 3″ OAL