Dynabrade 54789 Air Angle Grinder 4 in 12000 Rpm 0.70 Hp

Product Description

The DYNABRADE 54789 is a pneumatic angle grinder designed for heavy-duty material removal, grinding, and surface preparation in industrial and fabrication environments. It accepts a 4 inch diameter wheel and spins at 12,000 RPM, driven by a 0.70 HP air motor that requires a 1/4 inch NPT air inlet and consumes 40 CFM at 90 psi. The rear exhaust directs spent air away from the work surface, keeping the operator's line of sight clear. A triggerlock function allows sustained operation without continuous trigger pressure, reducing hand fatigue during extended use. Installation and operation are handled by qualified maintenance technicians and tool-room professionals working in metal fabrication, automotive, aerospace, and general manufacturing.

The 54789 is suited for metalworking applications requiring a compact, right-angle grinding posture. The 3/8-24 spindle accepts standard 4 inch depressed-center wheels, Type 27 grinding wheels, and compatible accessories available through tool supply channels. At 4.2 pounds, it is manageable for overhead and vertical surface work. Typical applications include weld blending, rust removal, deburring, and edge grinding on steel, aluminum, and cast iron workpieces in shop or field settings.

Key Features

• 4 inch wheel diameter with 3/8-24 spindle thread for broad accessory compatibility
• 12,000 RPM free speed for aggressive material removal
• 0.70 HP air motor powered at 90 psi operating pressure
• Rear exhaust directs airflow away from the work zone
• Triggerlock for sustained grinding without continuous trigger engagement
• 1/4 inch NPT air inlet fits standard shop air line fittings

Compatibility

Designed for use with standard 4 inch diameter grinding wheels and abrasive accessories threaded to a 3/8-24 spindle, compatible with typical pneumatic tool air supply systems operating at 90 psi.

Installation Notes

Installation and tool changes must be performed with the air supply disconnected and all residual pressure bled from the line. A licensed or trained pneumatic tool technician should verify that the shop air system delivers adequate CFM and regulated pressure before connecting the tool. Always confirm that mounted wheel or accessory speed rating meets or exceeds the 12,000 RPM spindle speed before operation. Follow ANSI B186.1 safety guidelines for the use of portable air tools.