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4″ Up-Shear Surfacing Bit w/ Replaceable Carbide Inserts – Whiteside SBU40-3 (AstraHP Coated)

This Up-Shear spoilboard surfacing bit measures 4″ wide and comes with 3 *Astra Coated* carbide inserts that can be used on all four cutting edges. AstraHP Coated 3/4″ Shank 4″ Large Diameter 3 wing body Made in USA

4″ Up-Shear Surfacing Bit w/ Replaceable Carbide Inserts – Whiteside SBU40-3 - Main image
Whiteside SBU40-3 Spoilboard flattening bitWhiteside SBU40-3 Spoilboard flattening bit
$372.7 $610.99 In stock

Category: Flattening, Surfacing, & Planing CNC Router Bits

This Whiteside SBU40-3 surfacing bit is designed for flattening, surfacing, and planing operations on CNC routers. It features replaceable carbide inserts and an AstraHP coating, offering a practical solution for spoilboard leveling and similar surfacing tasks.

  • Up-shear design for efficient chip evacuation and a cleaner cut.
  • Replaceable carbide inserts help extend the tool's service life.
  • AstraHP coated for enhanced performance and durability.
  • Ideal for use on CNC routers for surfacing and flattening applications.
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United States · Return window (days after delivery): 30. Return method: By mail. Return postage: Seller pays.

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Customer Reviews (4.8 / 5 · 5 reviews)

Ava ★★★★★

Cut through a rough slab of black walnut like butter, and the AstraHP coating kept chip buildup to a minimum even during heavy passes. The replaceable inserts snapped in without any fuss, so I didn’t have to stop and sharpen mid-project.

Samuel V. ★★★★★

The replaceable carbide inserts are a game-changer for saving time and money—just swap them out instead of buying a whole new bit. The AstraHP coating seems to help the bit glide through walnut with noticeably less heat buildup than my old uncoated one. This surfacing bit leaves a finish smooth enou

Avery A. ★★★★★

I’ve been using this bit for flattening large slabs, and the replaceable carbide inserts are a game-changer—no more needing to sharpen the whole bit. The AstraHP coating seems to help the chips clear smoothly, and it leaves an impressively clean finish right off the router.

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