DeWalt 3/8 in Drive Universal Impact Socket — 6-point (5/16 in)

Why this little universal stays in my impact kit

A 5/16-inch hex doesn’t sound like a size that deserves its own universal impact socket, but the reality of engine bays, HVAC plenums, lawn equipment, and sheet-metal work says otherwise. So many worm-drive clamps, hex-washer-sheet screws, and tight little fasteners live in places where a straight shot is a fantasy. That’s where the DeWalt 5/16-in universal impact socket earns its keep. I’ve been using it on hose clamps tucked behind throttle bodies, tin screws along a furnace trunk, and stubborn clamps on a marine bilge pump. It hasn’t left my 3/8-inch impact drawer since the first day.

Build and finish

The socket is built from heat-treated CR-440 steel with a black oxide coating. The overall length is just over 2-1/8 inches, and the drive end measures about 7/8 inch across, so it feels substantial in hand for such a small size. The yoke and cross-pin in the universal joint look cleanly machined with no ragged edges or burrs, and the pivot tolerances are tighter than I usually see in budget universals. The black oxide is even and matte—easy to grip with dirty hands and not the mirror-finish you’d find on chrome sockets. It will protect against glare and minor corrosion, but like any black-oxide finish, it appreciates a quick wipe of oil if you’re working around salt or water.

Laser-etched markings are big and legible on both the body and the drive side. After several wipe-downs with brake cleaner and parts wash, they’re still high-contrast. Nice touch, especially on a size I grab constantly.

Fit, grip, and fastener protection

This is a 6-point profile, and it behaves the way a 6-point should: it loads the flats, not the corners. On worn or slightly rounded clamp screws, I could really lean on the gun without camming out. The broach is centered and square; there’s no hint of slop on the fastener. With hex-washer sheet-metal screws, where the heads can be a touch inconsistent, the socket still bites predictably. If you’re transitioning from a 12-point universal, you’ll notice the difference—less chatter, less head damage, and more confidence with an impact.

Depth-wise, there’s about 9/16 inch of engagement before you hit the well. That covered the collars on my larger worm-drive clamps and the occasional protruding sheet-metal tip without bottoming out.

Access and geometry

Universal sockets are a compromise between reach, articulation, and bulk. This one is compact enough at the nose to get into clamp forests around radiators and turbos, yet stout enough at the drive end to survive an impact wrench rattling through rusted hardware. The joint’s range of motion is generous; I could hit a clamp tucked under a plastic intake tube at close to a 30-degree offset and still get solid drive.

There’s a bit more girth at the drive end than a separate 5/16 socket on a slim U-joint, so for truly claustrophobic spots, I still reach for a 1/4-inch drive setup or a wobble extension. But as a one-piece solution that stays together on the gun and doesn’t fling parts, this design strikes a practical balance.

On the gun: performance

I ran it on both a small cordless 3/8 impact and a compact air gun. It seats securely on detent-ball anvils and is also O-ring/retaining-pin compatible for through-hole anvils—handy when you’re working overhead or near a bay where launching a socket means it’s gone for good. With the pin-and-ring in place, it never walked off the anvil, even during long runs on rows of sheet screws.

The joint stiffness out of the box was on the tight side. That’s not unusual; a drop of light oil and a few minutes of cycling under load smoothed it out. It keeps just enough friction to hold an angle, which makes starting screws and clamps far less fiddly. Under hammering loads, there’s no clackety backlash—just a controlled transfer of torque.

Durability over time

Heat-treated CR-440 and a stout yoke inspire confidence, and so far the socket has backed that up. I’ve hammered off corroded stainless clamps on a boat trailer and buzzed through dozens of HVAC screws without any visible peening on the drive square or mushrooming on the nose. The cross-pin retains its shape; the joint hasn’t developed meaningful play. The black oxide will show bright spots on edges after heavy use, but that’s cosmetic. A quick wipe with oil at the end of the day keeps surface rust at bay.

At half a pound, it’s heavier than a standard 5/16 socket, which is expected given the integrated joint. That mass hasn’t been a downside; if anything, it damps some of the chatter you can get with cobbled-together extensions.

Ergonomics and identification

High-visibility laser etching and a consistent profile make it easy to grab the right piece with dirty gloves. The size marking is readable from a distance—no hunting through a pile of black sockets. The knurled feeling you sometimes get on black oxide is present enough to help, but not so rough that it chews up gloves.

Quirks and limitations

• Initial joint stiffness: Mine needed a drop of oil and a short break-in. After that, it moved freely while still holding an angle.
• Bulk at the drive end: The 7/8-inch drive-side diameter can be a squeeze in extremely tight cavities. For those, a 1/4-inch drive setup or a separate universal plus a thin-wall socket can be better.
• Black oxide care: It’s not rust-proof. If you’re around moisture or salt, wipe it down and give it a light oil film.
• Single-purpose size: This is a specialist—fantastic for clamps and small hex heads, but you’ll still want neighboring sizes (1/4, 8 mm, 10 mm) if you’re building out a kit.

None of these are deal-breakers; they’re predictable trade-offs with this category of tool.

Alternatives and pairing tips

If you already carry a wobble extension and a standard 5/16 impact socket, you can replicate some of the access this piece provides with a slimmer profile. The trade-off is stability—the integrated universal holds an angle and doesn’t shed parts. For a full clamp-and-sheet arsenal, I pair this with 1/4- and 8 mm universals, plus a long 5/16 magnetic nutsetter for the driver. That mix covers most automotive, marine, and HVAC work without constant bit swapping.

Manufacturing and consistency

Mine is made in Taiwan, and the workmanship reflects the better end of that spectrum: square broach, concentricity at the nose, and clean pivot work. No high spots, no gritty feel, and the laser etching is crisp. The included compatibility with O-ring and retaining pin is a plus if you’re using air impacts or working overhead.

The bottom line

The DeWalt 5/16-in universal impact socket is a quietly excellent problem-solver. It grips small hex heads securely, survives real impact use, and gets into angles where straight sockets stall out. The build is solid, the markings are easy to read, and the universal joint strikes a practical balance between stiffness and freedom once it’s broken in. You can nitpick the drive-end bulk or the need for a light oiling, but in daily use those fade behind the simple fact that this socket makes clamp and sheet-metal work faster and less frustrating.

Recommendation: I recommend it. If you regularly deal with 5/16-inch clamps and hex-washer screws, this socket earns its spot by combining a secure 6-point grip with a durable universal joint, clear markings, and impact-ready construction. It’s a reliable, purpose-built tool that saves time in tight quarters and holds up to real-world abuse.