Accusize 4in/100mm Extension for 3/4in Weldon Shank Annular Cutter

In this review the Accusize 4in/100mm Extension is evaluated as a simple, purpose-built accessory for users who need extra depth with 3/4in Weldon shank annular cutters. The bottom line: this extension adds a reliable 4in of reach while preserving the secure Weldon shank connection and alignment needed for deep hole drilling. It is best for machinists and fabricators who already use 3/4in Weldon cutters and need dependable extended reach rather than a different cutter type.

Key Features

• Extended Reach: Adds 4in/100mm to annular cutters to access deeper workpieces without changing cutter type.
• Shank Compatibility: Fits 3/4in Weldon shank annular cutters for seamless integration with existing tooling systems.
• Precise Alignment: Includes a 1/4in pilot bore to keep the cutter centered and reduce walk during deep drilling.
• Robust Construction: Built to withstand demanding machining conditions so it holds up under repeated use.
• Weldon Shank Design: The Weldon flats provide a slip-resistant connection to maintain torque transfer and safety.

Who It's For

This extension is aimed at professional machinists, metal fabricators, and maintenance shops that routinely drill deep holes and already run 3/4in Weldon shank annular cutters. It is a practical choice when users need to extend cutter depth without switching machines or cutters.

Users who do not use 3/4in Weldon shank tooling, require variable-length extensions, or need integrated coolant channels should look elsewhere; this product is a straightforward mechanical extender rather than a multifunctional adapter.

Pros & Cons

Pros

• Provides a full 4in/100mm of extra reach for deeper drilling tasks.
• Secure Weldon shank connection reduces slippage and maintains torque transfer.
• 1/4in pilot bore supports accurate cutter alignment and reduces wandering.
• Durable build suited to heavy-duty shop environments.

Cons

• Only compatible with 3/4in Weldon shank annular cutters, so it is not universal.
• Does not include coolant or chip evacuation features; users must rely on their setup for those functions.

Specifications

Dia. of Inner Hole	3/4in
Dia. of Pilot Pin	1/4in
Dia. of Shank	3/4in
OAL (Except Shank)	4in
Outer Shank Type	Weldon Shank
Primary Benefit	Extended reach for deep hole drilling

Our Verdict

The Accusize 4in/100mm Extension is a focused, well-built accessory for shops that need extra depth with 3/4in Weldon shank annular cutters. It offers clear value to users who already own compatible cutters by extending capability without compromising alignment or connection security, making it a practical, cost-effective solution for deep drilling tasks.

Frequently Asked Questions

Will this extension fit my cutter?
It fits annular cutters with a 3/4in Weldon shank; confirm your cutter shank diameter matches 3/4in.

Does it provide coolant through the extension?
No, this extension does not include internal coolant channels; coolant and chip control depend on your machine setup.

How does the pilot bore help performance?
The 1/4in pilot bore helps center the cutter and reduce lateral movement during deep drilling for more accurate holes.