Best Extra Long Drill Bits for Deep-Hole Drilling (2026)

We selected extra long drill bits by evaluating shaft length (18" options), material/coating (HSS, black-oxide, DWDDL), user ratings, and price-to-value for deep-hole drilling tasks

This roundup covers extra long drill bits designed for deep-hole drilling, focusing on long-reach high-speed steel options and common coatings used in industrial and workshop settings. Picks were chosen for shaft length, material and coating (HSS, black oxide, DWDDL series), user ratings, and value for deep drilling tasks

Top Picks

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    19/64 x 18 in high-speed steel extra long drill bit

    19/64 x 18 in high-speed steel extra long drill bit

    Drill America • ★ 3.9/5 • Budget

    High-speed steel drill bit with extra length for reach. Features black oxide for lubricity and coolant pockets near the edge; round shank for versatile toolholding. Customers note long flute length but mixed durability and sharpness

    • extra-long length
    • black oxide lubricity
    • round shank versatility
    Check current price on Amazon →
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    9/16" x 18" high speed steel extra long drill bit

    9/16" x 18" high speed steel extra long drill bit

    Drill America • ★ 3.8/5 • Mid-Range

    High-speed steel drill bit with extra reach for general drilling. Combines hardness and toughness with black oxide finish to reduce friction and help coolant retention near the cutting edge. Customers note sharpness and quality, with mixed durability and accuracy insights

    • extra long 18" reach
    • black oxide surface for lubricity
    • sharp, high-speed steel bit
    Check current price on Amazon →

Buying Guide

Shaft length vs. reach

Match bit length to the deepest hole you need; extra long 18" bits enable deep-hole drilling without extensions but require steady clamping and correct feed rates

Material: high-speed steel (HSS)

HSS offers good toughness and heat resistance for drilling metals and woods; the selected items emphasize HSS construction for durability in deep cuts

Diameter selection

Pick the smallest diameter that meets your tolerances to reduce cutting forces and improve straightness in deep holes—available sizes in this roundup span common fractional diameters

Drill setup and support

Use proper workholding, a rigid drill press or guide, and peck drilling or coolant for chip evacuation to avoid bit walking and breakage with long shafts