2pc Magnetic 1/4" to 4mm Hex Shank Bit Adapter – Alloy Steel

2-Pack Magnetic 1/4" Insert Bit Adapter – 6.35mm to 4mm Hex Shank

Get more versatility from your screwdrivers and precision tools with this compact, double-ended bit adapter set. Designed for fine, detail-oriented work, each adapter converts a standard 1/4" (6.35mm) insert bit drive to a 4mm hex shank bit system — giving you seamless compatibility across your precision screwdriver toolkit. The built-in magnet keeps your 4mm bits securely seated so you can work confidently without interruption.

At just 25mm in length, these adapters are intentionally compact to minimize wobble — a common frustration with longer bit adapters. Constructed from durable alloy steel, they're built to handle repetitive use while keeping your workflow smooth and steady.

Key Features

• Double-End Design: 1/4" (6.35mm) insert bit on one end, 4mm hex shank on the other for maximum versatility
• Magnetic Bit Retention: Built-in magnet securely holds 4mm bits in place during use
• Compact 25mm Length: Short profile minimizes wobble for more precise, controlled work
• Alloy Steel Construction: Strong and durable metal build for long-lasting performance
• Precision-Focused: Ideal for delicate, detail-oriented tasks — not intended for high-torque power tool applications
• Set of 2: Two adapters included so you always have a spare on hand

Specifications

• Material: Alloy Steel (Metal)
• Color: Gray
• Length: 25mm
• Drive Size: 1/4" (6.35mm) Insert Bit
• Shank Size: 4mm Hex
• Magnetic: Yes
• Quantity: 2 Pieces

What's in the Box?

• 2 × 1/4" to 4mm Hex Shank Bit Adapter

Note: Actual product color may vary slightly from images due to monitor brightness and lighting conditions. Please allow for minor measurement tolerances of ±1mm.

Made in China.

For guidance on tool safety and best practices in the workshop, visit the OSHA Hand & Power Tools Safety page.

Frequently Asked Questions

Q: What is the difference between a 1/4" insert bit and a 4mm hex shank bit?

A: A 1/4" (6.35mm) insert bit is the standard bit size used in most electric screwdrivers and precision ratchet drivers. A 4mm hex shank bit is a smaller format commonly used in compact precision screwdriver kits and electronics repair tools. This adapter bridges the two systems so you can use your 4mm bits in any standard 1/4" drive tool, or vice versa.

Q: Can I use this adapter with a power drill or electric screwdriver?

A: This adapter is engineered for precision work and light-duty applications, not high-torque power tools. It is best suited for use with manual precision screwdrivers, ratchets, or low-torque electric screwdrivers for tasks like electronics repair, eyeglass assembly, or other delicate work.

Q: Why is the 25mm length beneficial compared to longer adapters?

A: Longer bit adapters can introduce flex and wobble, making precise screw driving harder. At just 25mm, these adapters keep the bit close to the driver head, resulting in more stable, accurate control — especially important for intricate or delicate fastening tasks.

Q: Does the magnet hold the bit securely during use?

A: Yes. Each adapter features a built-in magnet that holds 4mm hex shank bits firmly in place, preventing the bit from slipping out during use. This is especially helpful when working in tight or hard-to-reach spaces where a dropped bit would be difficult to retrieve.