Hand Impact Drivers

About Hand Impact Drivers

Hand impact drivers are essential manual tools designed to deliver a powerful rotating force when struck with a hammer or mallet. Unlike their powered counterparts, these mechanical tools convert downward striking force into rotational torque, making them invaluable for loosening stubborn, seized, or over-tightened screws and fasteners. The ingenious cam-and-hammer mechanism inside a hand impact driver generates significantly more turning power than a standard screwdriver could ever achieve through manual force alone, whilst simultaneously applying downward pressure to keep the bit firmly seated in the screw head.

Our range of hand impact drivers includes both complete sets and individual components from trusted manufacturers including Wera, Draper, Sealey, and Facom. Whether you're looking for a comprehensive impact driver kit with multiple bits and adaptors, or replacement bits for an existing tool, you'll find professional-grade options suitable for workshop use and on-site applications. Most hand impact drivers feature a 1/2" square drive or hexagon shank connection, allowing compatibility with a wide range of impact-rated screwdriver bits and sockets.

These tools are particularly valued by mechanics, engineers, and tradespeople who regularly encounter corroded fixings, painted-over screws, or fasteners that have been overtightened. A quality hand impact driver can often mean the difference between successfully removing a problematic screw and having to resort to drilling it out, saving both time and money whilst preserving the integrity of the workpiece.

Jargon Buster

• Impact Mechanism: The internal cam-and-hammer system that converts a striking blow into rotational force. When you hit the end of the driver with a hammer, this mechanism translates the impact into powerful twisting motion.
• Hexagon Shank: A six-sided bit connection, typically 8mm or 1/4", that prevents the bit from slipping within the chuck. Hex shanks are standard on most impact driver bits and provide a secure, wobble-free connection.
• Square Drive: A four-sided socket connection, commonly 1/2" on hand impact drivers, that accepts standard impact sockets and adaptors. This system is widely used in automotive and mechanical applications.
• Impact-Rated Bits: Specially hardened screwdriver bits manufactured to withstand the sudden rotational forces generated by impact drivers. Standard bits can shatter under impact use, making impact-rated bits essential for safety and longevity.
• Torque Multiplication: The mechanical advantage gained through the impact mechanism that allows significantly greater turning force than manual screwdriving alone, particularly useful for seized or rusted fixings.
• Reversible Action: The ability to switch the rotation direction between clockwise (tightening) and anticlockwise (loosening), typically controlled by a selector on the tool body.

Who Uses Hand Impact Drivers?

Hand impact drivers are relied upon by a diverse range of professionals and DIY enthusiasts:

• Motor Mechanics and Auto Electricians: For removing seized engine components, rusted screws on exhausts, and corroded fixings on older vehicles
• Plant and Machinery Fitters: When maintaining industrial equipment with fasteners exposed to harsh environments
• Marine Engineers: Essential for working with corroded fixings on boats and marine equipment where salt exposure is common
• Agricultural Engineers: For servicing farm machinery and equipment that's been exposed to soil, moisture, and chemicals
• HVAC Engineers: Removing painted-over or weathered screws on external units and access panels
• Restoration Specialists: Whether working on classic cars, machinery, or furniture with period fixings
• Maintenance Engineers: Across all industries where equipment servicing involves removing seized or damaged fasteners
• DIY Enthusiasts: Particularly those working on automotive projects, restoration work, or dealing with older properties

How to Choose the Right Hand Impact Drivers

Selecting the appropriate hand impact driver depends on several key factors:

Drive Size: The 1/2" square drive is the most common and versatile option, offering compatibility with a vast range of sockets and adaptors. If you're primarily working with screwdriver applications, a hex shank model may be more suitable, though many sets include adaptors for both.

Set Contents: Consider whether you need a complete kit or individual components. Comprehensive sets from brands like Wera, Draper, and Sealey typically include the impact driver body, a selection of the most commonly used bits (Pozi, Phillips, slotted, and hex), and often socket adaptors. These represent excellent value for those starting out or equipping a new toolbox.

Bit Quality and Variety: Impact-rated bits are essential and non-negotiable for safety. Check that sets include the specific drive types you encounter regularly. Pozi bits are ubiquitous in UK applications, whilst Phillips remain common in imported equipment and electronics. Hex bits are increasingly popular in modern fixings.

Build Quality: Professional-grade impact drivers from manufacturers like Facom and Wera feature hardened steel construction and precision-machined mechanisms that deliver consistent performance over years of heavy use. The handle should be comfortable and provide good grip, whilst the reversing mechanism should be positive and easy to operate even when wearing gloves.

Case and Storage: A sturdy case keeps your impact driver and bits organised and protected. This is particularly important on site where tools can easily be damaged or components lost. Many quality sets include blow-moulded or metal cases designed for workshop or van storage.

Brand Reputation: Established brands like Wera, Sealey, Draper, and Facom have proven track records for reliability and often provide better warranty support and replacement part availability compared to budget alternatives.

Popular Accessories

• Impact-Rated Screwdriver Bit Sets: Additional Pozi, Phillips, Torx, and hex bits in various sizes to expand your driver's versatility
• Impact Socket Sets: 1/2" drive impact sockets for use with square drive impact drivers, particularly useful for automotive applications
• Drive Adaptors: Convert between 1/2" square drive and hex shank connections, or step down to 3/8" or 1/4" drives
• Screw Extractors: Specialised bits designed to grip and remove damaged or stripped screws that the impact driver has loosened
• Dead Blow Hammers: Provide controlled striking force without damaging the impact driver or surrounding components
• Penetrating Oil: Products like WD-40 or Plus Gas help free seized threads before using the impact driver
• Bit Holders and Organisers: Keep your growing collection of impact bits organised and easily accessible
• Replacement Springs and Internal Components: For maintaining and servicing your impact driver over its working life

Safety Information

Whilst hand impact drivers are relatively straightforward tools, proper safety practices ensure effective and injury-free operation:

Eye Protection: Always wear safety glasses or goggles when using an impact driver. The striking action can cause bits to shatter if worn or damaged, and working with seized fasteners increases the risk of debris or rust particles being dislodged.

Appropriate Striking Tool: Use only a proper hammer or dead blow mallet to strike the impact driver. Never use damaged hammers or improvised striking tools. Ensure your hammer is of appropriate weight—typically 500g to 1kg for most applications.

Bit Inspection: Regularly inspect impact bits for wear, cracks, or damage. Worn bits are more likely to cam out (slip from the screw head) and damaged bits can shatter under impact. Replace any questionable bits immediately.

Secure Workpiece: Ensure the component you're working on is properly secured or supported. The impact forces can cause movement, potentially leading to injury or damage.

Correct Bit Selection: Use only impact-rated bits with hand impact drivers. Standard screwdriver bits are not designed for impact forces and can fail catastrophically. Always match the bit type and size precisely to the fastener.

Proper Alignment: Keep the impact driver perfectly aligned with the screw or fastener. Angled striking can cause the bit to slip, damage the fastener head, or result in bent tools.

Glove Consideration: Whilst gloves protect your hands, ensure they don't reduce your grip security. A firm, controlled grip on the impact driver handle is essential for safe operation.

Frequently Asked Questions

What's the difference between a hand impact driver and a powered impact driver?

A hand impact driver is a manual tool that converts hammer strikes into rotational force, making it ideal for loosening seized or stubborn screws without requiring electricity or batteries. Powered impact drivers deliver rapid rotational impacts for driving screws quickly into materials. Hand impact drivers excel at removal and dealing with corroded fasteners, whilst powered versions are better suited to repetitive fastening applications. Many professionals keep both types as they serve complementary purposes.

Can I use regular screwdriver bits in a hand impact driver?

No, you should only use impact-rated bits specifically designed for impact applications. Regular screwdriver bits are manufactured from different steel grades and can shatter under the sudden forces generated by an impact driver, creating a serious safety hazard. Impact-rated bits are hardened and tempered differently to absorb shock loads safely. The small additional cost of proper impact bits is insignificant compared to the risk of injury from a shattered standard bit.

Will a hand impact driver damage screws or fasteners?

When used correctly with the appropriate bit size and type, hand impact drivers are actually less likely to damage fasteners than excessive force with a standard screwdriver. The impact action helps keep the bit seated firmly in the screw head, reducing cam-out that strips the drive recess. However, it's important to ensure good bit-to-fastener engagement and avoid excessive striking force, particularly with softer materials or smaller screws.

How do I know which direction my impact driver is set to?

Hand impact drivers feature a direction selector, typically a collar or switch on the tool body clearly marked with arrows or the words "loosen" and "tighten". Before striking, always verify the direction setting matches your intended operation. Some models use a right-hand thread principle—rotate the selector clockwise for clockwise (tightening) rotation, and anticlockwise for anticlockwise (loosening) rotation. When in doubt, consult your tool's instructions.

My impact driver isn't loosening a stuck screw—what should I try?

First, apply penetrating oil and allow it to work for several minutes or even overnight for severely corroded fixings. Ensure you're using the correct size and type of impact-rated bit with a perfect fit in the screw head. Verify the impact driver is set to the loosening direction. Try alternating between loosening and tightening strikes to help break the corrosion bond. If the screw head is damaged or stripped, consider using a screw extractor. For extremely stubborn fasteners, careful application of heat (where safe and appropriate) can help break corrosion before using the impact driver.