Makita GA5020 (10.5 Amp 5 in. SJS Corded Angle Grinder with AC/DC Switch)

By Makita · Angle Grinders · Power Tools

  • Wheel 5 in
  • Motor 10.5 A
  • Speed 11,000 RPM
  • Weight 5.9 lb
  • Spindle 5/8-11

Lowest price seen
~$209.00 (approx.)
from $209.00 at Amazon

Prices are snapshots. Check the current price with the store.

Summary

A 5-inch, 10.5 Amp corded angle grinder for welders, fabricators and contractors, with a mechanical clutch that protects the gears when the wheel binds. Check the switch before you buy: Makita’s page says no lock-on, the manual describes a lock lever, and at least one retailer lists Lock-On: Yes.

Strengths

  • Owners value the SJS mechanical clutch: when the wheel binds, it disengages the drive shaft, the gears survive, and no restart is needed.
  • Owners appreciate the electric brake for productivity.
  • Brushes sit behind external caps, so you can replace them in the field without a strip-down.
  • The AC/DC switch runs the tool from a generator or DC supply, a feature less common on modern grinders.
  • The labyrinth-sealed motor uses zig-zag varnish on the armature coil and spiral bevel gears for dust protection.
  • Owners in r/Tools and r/Makita praise the build quality and recommend the GA5020 as a starter professional grinder.

Weaknesses

  • No variable speed and no constant speed control; those electronics sit in the GA5020C variant.
  • The lock-on question does not line up across sources: Makita’s page says no lock-on, the manual describes a lock lever, and Burns Tools lists Lock-On: Yes.
  • No established outlet has published instrumented test data for this model.
  • Owner feedback is limited in volume, so long-term reliability rests on reputation rather than data.

Verified specifications

Wheel diameter5 in (125 mm); spindle thread 5/8-11 UNC.
Motor10.5 A, 1,050 W input.
No-load speed11,000 RPM.
Dimensions14 in (356 mm) overall length; 5.9 lb (2.7 kg) net weight.
Switchrear-handle trigger; Makita USA specifies no lock-on feature.
Electric brakeyes.
ClutchSJS (Super Joint System) mechanical clutch.
Brushesexternally accessible for field replacement.
Power inputAC/DC switch for generator or DC sources; 8 ft (2.5 m) cord.
Speed controlno variable speed and no constant speed control; those sit in the GA5020C variant.
Max wire cup brush90 mm (3-1/2 in).
Country of originUSA.
In the box5 in grinding wheel (36 grit INOX), tool-less wheel guard, lock nut, lock nut wrench, inner flange, side handle.
Warrantyone year from the original purchase date.
Full research notes and sources

The SJS clutch and motor protection

The Super Joint System is a mechanical clutch, not electronics. When the wheel binds, the clutch disengages the drive shaft so the gears escape damage, and unlike some electronic clutch systems the grinder does not need a restart. Around the motor, Makita uses labyrinth construction and a zig-zag varnish on the armature coil to keep dust and debris out, plus spiral bevel gears for smoother rotation.

The trigger switch question

Makita’s USA product page describes a rear handle trigger switch with no lock-on feature. The shared GA5020/GA6020 manual includes a lock lever for continuous operation instead: push the lock lever in, pull the trigger, then push the lever further in. Burns Tools lists Lock-On: Yes for the GA5020; PartsSource lists Lock-On: No. The GA5020Y variant takes a different path with a lock-off switch that prevents accidental activation. Treat the switch configuration as something to verify at purchase.

Running costs, parts and where to buy

Day-to-day costs are consumable grinding and cutting wheels. Brushes wear out, but they sit behind external caps and are cheap to swap, and Makita publishes a parts breakdown for the GA5020 on its product page, with brushes, guards, flanges, lock nuts and side handles commonly stocked by parts retailers. The manual asks you to hold the grinding wheel at about 15 degrees to the workpiece and to follow the break-in procedure for new wheels. The warranty runs one year from the original purchase date.

US retail prices in October 2026: Home Depot lists the GA5020 at $189.00, while Burns Tools, Toolup and Pacific Power Tools list it at $209.00. PartsSource, an industrial supply channel rather than a typical retailer, asks $302.32. Makita Canada sells a factory-reconditioned GA5020-R at CA$53.00.

Is it worth it?

At $189.00 it is strong value for a professional-grade grinder with an SJS clutch and an electric brake. At $209.00 it is fairly priced, but it sits against newer brushless cordless models and Makita’s own variable-speed corded grinders. If you work from a generator or a DC supply, the AC/DC switch adds job-site flexibility. If constant speed under load matters, the GA5020C variant has the electronics this model leaves out.

Which model this is

This page covers the Makita GA5020, a 5-inch corded angle grinder, UPC 088381-083249. The Amazon listing for this tool is ASIN B002BA5YNK. Related variants include the GA5020Y kit, the GA5020C with constant speed control, and the GA6020 line with a 6-inch wheel. One Home Depot listing wrongly claims 10,000 RPM for this tool; the official spec is 11,000.

Sources

Manufacturer:

Independent reviews:

  • No instrumented independent test from an established outlet has been published for this model; specialist comparison sites list the GA5020 without dedicated test data (Makita angle grinder comparison).

Owner reports:

Parts and stores:

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