The Sonic ST-4460A is a high-performance ¼″ hex shank pneumatic impact screwdriver featuring a two-hammer (twin-hammer) mechanism. It is designed for fast bolt/nut/screw driving in demanding industrial or assembly-line environments. With a free speed up to 8,000 rpm (and cited up to 12,000 rpm in some specs) and a compact overall length (~190 mm / 7½″) it combines speed with accessibility.
Features
:- Two-hammer impact mechanism : Offers rapid impact action for efficient fastening and higher durability compared to single hammer types
- ¼″ (6 mm) hex shank for standard driver bits.
- Free speed up to ~8,000 rpm (some materials list 12,000 rpm) for fast operation.
- Max torque in the range ~20-60 in-lbs (≈23-69 kg-cm) depending on conditions.
- Air consumption around 6 cfm (≈170 L/min) at recommended pressure (~90 psi / 6.2 bar).
- Compact overall length (190 mm) and relatively low weight (≈1.23 kg / 2.7 lbs) for this class.
- Quick-change chuck - enables fast bit changes to minimise downtime.
- Standard ¼″ PT/NPT air inlet thread and recommended hose size (3/8″ I.D. ≈ 9.5 mm) for proper air supply.
- Ergonomic design suitable for repetitive use in assembly or production line settings.
- Setup
- Connect to a properly set up compressed-air supply: The spec indicates an air pressure of ~90 psi (≈6.2 bar).
- Use an air hose of recommended inner diameter (e.g., 3/8″ I.D = ~9.5 mm) to ensure minimal pressure drop. Spec indicates 3/8″ hose size.
- Ensure the air line has a filter/regulator/lubricator (FRL) so that the tool receives clean, dry, properly lubricated air — this is key for impact tools.
- Insert the correct driver bit (1/4″ hex shank) securely into the quick-change chuck. Confirm bit is rated for impact use if needed.
Applications
:- Assembly of small to medium-sized components where high speed and moderate to high torque are needed — for example, sheet-metal frames, brackets, chassis parts, automotive interior assemblies.
- Production-line fastening where repeated screws need to be driven quickly and with consistent force. The 1/4″ hex shank allows for standard bits/sockets. The spec lists a capacity for bolt size 5/23″ (≈4 mm) and a max torque in the range ~20-60 in-lbs (≈23-69 kg-cm) for the ST-4460A.
- Maintenance, repair & overhaul (MRO) tasks in workshops where instant impact action helps loosen or tighten screws/bolts that standard screwdrivers struggle with.
- Light-to-medium industrial fastening tasks, such as mounting machine guards, panels, brackets, trays, or assembling sub-components that require faster throughput than ordinary screwdrivers.
- Any situation where the tool’s two-hammer mechanism provides rapid hammering action, helping deliver torque quicker and reducing cycle time compared to non-impact drivers. when the tool is idle or for maintenance.
Usage
:Setup
- Connect to a properly set up compressed-air supply : The spec indicates an air pressure of ~90 psi (≈6.2 bar).
- Use an air hose of recommended inner diameter (e.g., 3/8″ I.D = ~9.5 mm) to ensure minimal pressure drop. Spec indicates 3/8″ hose size.
- Ensure the air line has a filter/regulator/lubricator (FRL) so that the tool receives clean, dry, properly lubricated air — this is key for impact tools.
- Insert the correct driver bit (1/4″ hex shank) securely into the quick-change chuck. Confirm bit is rated for impact use if needed.
Operation
- Choose the correct bit and ensure the fastener is the right size (as specified ~4 mm bolt size capacity) and properly seated.
- Align the bit squarely on the screw or bolt head; start the driver by gently pulling the trigger and letting the tool build up to full speed before applying pressure.
- Use steady, moderate pressure — let the tool do the work. Avoid excessive push force which can lead to cam-out or damage to fastener or bit.
- For tightening : Allow the tool to drive the fastener until the impact action indicates the job is done; you may still verify final torque if required.
- For loosening : Set the forward/reverse switch appropriately (if present) and apply consistent back-off pressure while activating the tool to break fasteners free.
- After each use, release the trigger, allow the tool to come to rest, and inspect the bit and fastener.
Safety & Ergonomics
- Wear appropriate PPE: eye protection (impact-rated), hearing protection (impact tools generate noise), gloves if needed.
- Keep your workspace clear of obstructions. Ensure the air hose is routed away from operator trip zones.
- Do not use the tool in flammable or explosive atmospheres unless explicitly rated for that environment.
- Do not overreach or use the tool in awkward body positions where you may lose control when the tool hits impact.
- Disconnect air supply when changing bits, performing maintenance or when the tool is idle for extended periods.