air hammer
A hammer powered by compressed air.
air hammer: pneumatic percussive tool for breaking and chiseling
An air hammer is a handheld power tool that converts compressed air into rapid reciprocating motion to drive a chisel or point against a workpiece. Unlike rotary drills or impact drivers, an air hammer operates on a simple piston principle, delivering hundreds of controlled blows per minute. The tool consists of an air inlet, an internal valve system that meters compressed air alternately above and below a piston, and a chuck that holds interchangeable bits. It produces its characteristic rapid tapping sound and has minimal rotational force, making it ideal for work where rotation would be destructive or unwanted.
Construction and demolition work relies on air hammers for concrete breaking, mortar removal, and tile chiseling. A typical unit requires 4 to 8 CFM (cubic feet per minute) of compressed air at 90 PSI and weighs between 3 and 8 pounds. Smaller versions called air chisels are used for detail work like grout removal or scaling rust from steel; larger breakers designed for foundation work can exceed 15 pounds and deliver more aggressive blow force. The choice of bit varies by task: blunt points for general breaking, flat chisels for mortar joints, and specialized shapes for specific demolition scenarios.
Common failures and maintenance
Air hammer performance degrades when compressed air carries moisture, which corrodes internal components and reduces piston speed. A properly installed moisture trap in the air line significantly extends tool life. The tool should be oiled periodically with light pneumatic tool oil; neglecting this causes the valve to stick and the piston to move sluggishly. Worn pistons and valve seals are the primary failure modes, typically after several hundred hours of use depending on air quality and maintenance.
The term 'air hammer' is sometimes used interchangeably with 'pneumatic hammer' or 'pneumatic chisel,' though strictly speaking a chisel is the smaller variant for finer work. The naming reflects the tool's action: it hammers rather than cuts or drills. On jobsites, workers often call them by brand names or simply 'breakers,' though this can cause confusion with the larger hydraulic breakers used on demolition equipment.