JCB Pro 18V 620Nm Impact Wrench Review - JCB-18PIW-620

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JCB Pro 18V 620Nm Impact Wrench Review (JCB-18PIW-620) - and How It Compares to the 350

By Mark Moore, Power Tools Editor · Updated 23 July 2026 · 10 min read

When we reviewed the JCB-18PIW-350, the verdict was "nut-busting bargain". JCB has since added a bigger sibling: the JCB-18PIW-620, a ½" square-drive wrench pitched at mechanics, builders, scaffolders and agricultural users, the buyers for whom 350Nm occasionally meets a bolt that laughs at it. This review covers what the extra money buys, and just as important who shouldn't spend it.

(Platform context in our Pro 18V buying guide.)

Specifications

Torque literacy: working vs breakaway

Impact wrench marketing loves the big number, so credit to JCB for publishing both: 400Nm is what this wrench fastens and drives with; 620Nm is the hammering peak it applies to crack a stuck fastener loose. When comparing wrenches across brands, compare like with like, a rival's headline figure may be either. In practice the split is exactly what you want: 400Nm working torque runs down scaffold fittings, plant bolts and trailer hardware briskly, and the breakaway reserve is for the corroded, over-torqued and thread-locked fasteners that define farm and recovery work.

Control that prevents carnage

620Nm without control is a stud-snapper. The 3+1 arrangement,  200/300/400Nm steps plus the breakaway mode, with digital 3-speed control and a variable trigger is what lets one tool run down a wheel nut politely and murder a seized pivot bolt an hour later. The ½" drive wears a friction ring for quick socket swaps (use impact-rated sockets only - chrome sockets shatter), and the brushless motor, LED and reverse round out a spec with no obvious gaps. One professional habit this power demands: final-tighten wheel nuts and critical fasteners with a calibrated torque wrench,  an impact wrench removes and runs down; the click wrench finishes. JCB sells those too, which is either convenient or knowing, depending on your mood.

620Nm or 350N,? The honest split

The honest advice hasn't changed since our 350 review: for seasonal wheel swaps and home-workshop duty, the 350 at £89.99 remains the value pick - 350Nm defeats the wheel nuts of ordinary life. The £40 step to the 620 buys headroom that matters when fasteners live outdoors, carry thread-lock, or were last touched by someone with an air gun and no conscience: farms, scaffolds, plant yards, trailers. If you're reading the "best for" row and recognising your week, you already know which you are.

The JCB-18PKIT-5 angle: the maintenance kit

For the agricultural and plant audience there's a purpose-built bundle: JCB-18PKIT-5 (£325.00) pairs this wrench with the JCB-18PGG-VS grease gun we've reviewed, two 5.0Ah E-TECH batteries, the fast charger and a heavy-duty bag - effectively the cordless service kit for anyone maintaining tractors, mowers, plant and machinery. Given 5.0Ah packs sell at £54.98 each and the charger at £19.99, the bundle arithmetic works the way JCB's kits reliably do. It's the natural companion purchase for readers of our machinery maintenance guides.

Garden Review is reader-supported. Links to JCB Tools on this page are affiliate links - we may earn a commission on qualifying purchases at no extra cost to you. This does not influence our advice or ratings. Prices verified July 2026 and subject to change. Always use impact-rated sockets and final-torque critical fasteners with a calibrated torque wrench.