Makita 4-1/2″ SJS Paddle Switch Angle Grinder 10 AMP

The Makita 9564P delivers 10 AMPs and 10,500 RPM in a 5.1-pound package with the SJS mechanical clutch system that prevents kickback and gear damage when the wheel binds. Worth it for contractors who need grinding power with genuine safety protection. The clutch saves your wrists and your tool when you hit rebar in concrete or catch an edge wrong.

Skip it if you’re just cleaning up welds occasionally. The 9564P has been superseded by newer models like the GA5052 (11.0 AMP), but this grinder still earns its place for the combination of power and safety features.

SJS Technology and Power Specifications

The SJS™ mechanical clutch system protects the motor and gears from damage caused by binding or wheel stoppages, thereby extending the tool’s lifespan and reducing downtime. Think of it as a torque limiter for your grinder. When the wheel catches and stops suddenly, the clutch slips instead of transferring all that shock back through the gears and into your hands.

The power specs put this grinder in professional territory:

Specification	Value
Motor Power	10.0 AMP
No-Load Speed	10,500 RPM
Wheel Diameter	4-1/2”
Spindle Thread	5/8” - 11 UNC
Overall Length	12-1/8”
Net Weight	5.1 lbs (2.3 kg)
Power Cord	Approx. 8 ft

The large flush-mount paddle switch with integrated lock-off tab means you can grab this grinder from any angle and get it running. No hunting for a tiny trigger when you’re wearing heavy gloves in winter.

Durability Features and Real-World Performance

Labyrinth construction seals out the dust and debris that kills grinders on Montana jobsites. Zig-zag varnish protects the motor windings from the metal particles that float around welding shops. Spiral bevel gears run smoother and quieter than straight-cut gears.

Customer reviews highlight the safety clutch preventing kickback and the durable industrial-grade build as key strengths. The trade-offs? It’s heavier compared to low-amp models and limited by the cord. At 5.1 pounds, it’s not the lightest grinder on the shelf, but that extra weight comes from components built to last.

This grinder handles welding, fabrication, masonry, maintenance and repair, and construction tasks including grinding welds, cutting steel, stock removal, surface preparation, and cutting tile and masonry. Real contractors use it for everything from cleaning up structural welds to cutting rebar and prepping surfaces for coating.

The kit includes what you need to start working: side handle, 4-1/2” tool-less wheel guard, inner flange, lock nut, and lock nut wrench. The tool-less guard can be rotated for optimal protection without hunting for wrenches.

Makita backs it with a 1-year limited manufacturer warranty and UL listing. The model has been discontinued, but parts and service remain available through Makita’s network.

Frequently Asked Questions

Q: How does the SJS clutch actually work?

The Super Joint System® technology prevents motor and gear damage by allowing the drive shaft to slip if the wheel is forced to stop. It’s a mechanical clutch built into the gear case. When the wheel binds hard enough, the clutch disengages before the gears strip or the motor burns out.

Q: What size wheels does this grinder accept?

The grinder accepts 4-1/2” wheels with a 5/8”-11 UNC spindle thread. This is the standard size for most grinding and cutting discs in this class.

Q: How do you change wheels on this model?

Depress the spindle lock and use the lock nut wrench to loosen/tighten the lock nut on the 5/8”-11 spindle. The spindle lock button holds the shaft while you turn the nut.

Q: Is this grinder suitable for cutting metal?

Yes, it handles cutting steel as one of its primary applications. The 10 AMP motor and 10,500 RPM provide enough power for cutting operations with appropriate cutting discs.

Q: What safety features does the paddle switch include?

The paddle switch is equipped with a lock-off tab to prevent accidental engagement. You have to deliberately move the lock-off before the paddle will activate.