Best 3/8 Inch Impact Wrenches: Four Budget Cordless Options Tested Head to Head

Introduction

Dedicated 3/8 inch impact wrenches fill a useful niche: a shorter, lighter sidekick for day-to-day tasks like top-of-engine work and other jobs where a full mid-torque tool is more wrench than you need. Most major brands now offer one, usually with a smaller body and shorter length than their half-inch lineups. Here we compare four dedicated 3/8 inch models, all bought at typical retail prices, that each advertise around 160 ft-lbs yet deliver very different real-world performance.

Why Dedicated 3/8 Inch Impact Wrenches Exist

All four tools tested here are only offered in a 3/8 inch drive configuration, rather than being compact or mid-torque half-inch models repackaged with a smaller anvil. The category appeals to buyers who want something easy to carry and maneuver for light automotive and maintenance work.

Each tool was run through three power tests: a 5-second forward working torque test, a 10-second reverse max torque test, and a best-case 15-second run on a fresh battery. Size, price relative to power, and honesty of advertised claims were also factored into the comparison.

Ryobi ONE+ HP PSBIW1B

The Ryobi ONE+ HP PSBIW1B sells for $119 bare, though kits have been seen as low as $99, sometimes cheaper bare than buying the equivalent brushed kit. It is part of the HP line, meaning a brushless motor, but notably it lacks the terminal pickups for Ryobi’s HP battery communication tech, which is common on their lower-cost HP tools. In testing, swapping between a 3Ah HP pack and a newer 4Ah high-performance pack produced only trivial differences, so battery choice does not appear to matter much on this tool.

At 5.43 inches long, it is the smallest and shortest of the group, though the battery design limits how truly compact the overall package feels. Measured results were solid: 131 ft-lbs working torque, 183 ft-lbs max torque, and 201 ft-lbs in the best-case run.

Harbor Freight Earthquake EQ 3/8 XT 20V

The Earthquake EQ 3/8 XT 20V sells as a kit for $135 and is not available bare. It is the longest of the four at 6.7 inches, thanks to its brushed motor, while advertising the same 160 ft-lbs as the Ryobi.

Measured performance put it last on power: 119 ft-lbs working torque, 171 ft-lbs max torque, and 186 ft-lbs best case. Combined with its length, that makes it the least compelling package here, scoring roughly 27.8 ft-lbs per inch of length.

Craftsman V20 3/8 Impact Wrench CMCBF910B

The Craftsman V20 CMCBF910B costs $99 bare and advertises 165 ft-lbs. It is 5.7 inches long, brushless, and its specs do not appear to match any current DeWalt 3/8 inch models, suggesting it may be a unique design to the V20 line rather than a rebadge.

It was the standout performer. It delivered 168 ft-lbs working torque, 205 ft-lbs max torque, and a class-leading 230 ft-lbs in the best-case test, and it scored the best torque-per-inch figure at 40.4. In everyday use it surprised by removing caliper bolts and other fasteners you might not expect from a budget 3/8 inch tool.

Bauer 1783C-B1

The Bauer 1783C-B1 is the cheapest of the day at $70, and the most puzzling. Harbor Freight advertises 325 ft-lbs for it, but that figure is bolt breakaway torque, and no working or fastening torque spec is given at all. It is also essentially the same tool as Bauer’s hex drive impact driver, down to the injection-molded body and weight, yet the driver sells for around $40.

Despite the marketing fuzz, the tool performed respectably: 126 ft-lbs working torque, roughly 226 ft-lbs max torque, and 223 ft-lbs best case, nearly matching the Craftsman. At 6.5 inches long it is on the larger side, and its 69% score on advertised claims drags down an otherwise decent showing.

Things to Consider Before Buying

A dedicated 3/8 inch impact wrench should be small; otherwise, a mid-size half-inch option usually brings far more punch for similar money. That makes length and body size worth real weight in this class. Battery ecosystem matters too: if you already own packs from one brand, a bare tool purchase can be significantly cheaper than a kit.

Overall Buying Advice

The Craftsman V20 CMCBF910B is the clear pick from this comparison. At $99 it delivered the highest measured torque in every test, comes in a short 5.7 inch package, and proved capable of real automotive tasks like caliper bolts. The Ryobi is the better choice if you want the shortest overall tool and are already invested in Ryobi batteries, though its battery shape makes it bulkier than its 5.43 inch length suggests. The Bauer offers surprising power per dollar if you can look past its dubious 325 ft-lbs claim and longer body. The Earthquake is the weakest combination of power, length, and price here and is the hardest to recommend.

Conclusion

Among these four dedicated 3/8 inch impact wrenches, the Craftsman V20 hits above its weight and is the standout value at $99. The Ryobi is a compact runner-up, the Bauer is a cheap surprise with honest power but inflated marketing, and the Earthquake trails the field on both size and output.