A nut driver looks like a screwdriver with a socket on the end, and crews that carry one tend to reach for it several times a day. It tightens and loosens hex nuts, bolts, and threaded rod in spots where a ratchet and socket will not swing, and it doubles as a long-reach driver for hex-head screws. Because the tool does double duty, the practical basics of nut driver set selection for construction work come down to a handful of decisions: which sizes to cover, whether the shafts are hollow or solid, whether the drivers carry an impact rating, and what kind of handle the set ships with. Many current sets cover all four bases at once. A driver with an impact-rated hollow shaft runs under a cordless drill or impact driver, then drops into a screwdriver-style handle when the job calls for hand driving. That dual functionality is what separates a versatile set from a single-purpose tool.
Nut Driver Sizes and the Fasteners They Cover
Most jobsite nut driver sets are sold in inch sizes, and the six sizes that appear again and again are 1/4, 5/16, 3/8, 7/16, 1/2, and 9/16 inch. Each one matches a hex nut or bolt head found on electrical boxes, equipment mounts, threaded rod, and light mechanical assemblies. Metric equivalents run from about 6 mm to 14 mm, so a set built for inch fasteners will not help much on imported equipment unless metric drivers are included as well.
Which Sizes Show Up Most Often
- 1/4 inch: small machine screws, terminal lugs, and light fasteners in electrical work.
- 5/16 and 3/8 inch: the most common hex heads on brackets, conduit fittings, and general construction fasteners.
- 7/16 inch: structural screws and larger electrical fittings.
- 1/2 inch: heavier brackets, anchors, and equipment mounting bolts.
- 9/16 inch: large nuts on threaded rod and heavy hardware.
A typical six-piece set covers the range above with one driver per size, and the drivers usually share a common shank so they fit the same handle. Sets that skip a size or two save a little money, but they leave a gap on the jobsite exactly when a fastener of that size shows up.
Reading the Size Range Before You Buy
A five-piece or seven-piece set shifts the endpoints, so list the fastener sizes your crew actually touches and confirm the set covers every one of them. The same logic applies when choosing a precision screwdriver set: the driver types and handle styles in the box matter as much as the raw bit count.
| Driver size | Typical hex fastener | Common jobsite use |
|---|---|---|
| 1/4 inch | #8 to #10 machine screws | electrical terminals, small brackets |
| 5/16 inch | 1/4 inch hex bolts | conduit fittings, light fixtures |
| 3/8 inch | 5/16 inch hex bolts | framing brackets, straps |
| 7/16 inch | 3/8 inch hex bolts | anchors, medium hardware |
| 1/2 inch | 7/16 inch hex bolts | equipment mounts |
| 9/16 inch | 1/2 inch hex bolts | threaded rod, heavy hardware |
The table is a starting point. A crew that works mostly on one trade may need only three of these sizes, while a general crew benefits from the full set, and a set with metric drivers covers both worlds.
Hollow Shafts Versus Solid Shafts
The biggest functional difference between nut driver designs is whether the shaft is hollow. A hollow shaft lets the driver slide over threaded rod and long bolts so the socket reaches a nut that sits deep behind the threads. A solid shaft stops at the top of the fastener and limits how far the driver can seat. On a typical 5 inch shaft, the hollow core extends about 3-3/4 inches, which is enough to pass over most threaded rod found on a jobsite.
Hollow shafts also change how the driver engages the fastener. When the nut rides inside the hollow core, the driver keeps the engagement straight and reduces the chance of camming out of a partially stripped nut. The trade-off is cost: a hollow-shaft set costs more than a solid-shaft set with the same size range, and some buyers skip the hollow feature when their work is all open-access fasteners.
Spotting a Hollow Shaft at a Glance
Some manufacturers mark hollow-shaft drivers with a visual cue: drivers with two colored stripes on the shaft are hollow, while drivers with a continuous color are solid. The marking is not universal, so check the product description or measure the shaft depth before relying on it. Sets without hollow cores are cheaper and still fine for many jobs, but they cannot reach a nut on a long stud.
Manufacturers have shipped impact-rated multi-bit screwdriver and nut driver combinations for years, and the hollow-shaft detail is usually called out in the specifications because it decides whether the tool works on threaded rod at all.
Impact Ratings and Power Tool Compatibility
Not every nut driver is built to run under an impact driver. Impact tools deliver short, high-torque pulses, and a driver that is not impact-rated can crack at the shank or round off at the hex. Compact impact drivers commonly produce 1,500 to 2,000 inch-pounds of torque, which is far more than a hand driver ever sees. When a set is rated for impact use, the same driver works under an impact driver, a cordless drill, or a 1/4 inch hex bit holder, so one kit covers power driving and hand driving.
Matching the Driver to the Tool
- Impact driver: fastest for driving and removing, best paired with impact-rated drivers.
- Cordless drill with a bit holder: fine for light work, slower, and easier to control.
- Hand driving with the handle: maximum control for final torque on finished work.
Choosing nut driver bits for construction means checking size, impact rating, and shank compatibility together. A bit that fits a drill chuck will not necessarily survive an impact driver, and a bit built for an impact driver will not necessarily seat in a proprietary handle.
Speed Control Still Matters
An impact driver can spin a nut off faster than you can react, and over-tightening a nut on threaded rod is easy to do. Use the lowest speed setting for final seating and switch to hand driving when the fastener needs a precise torque. A quick test on a scrap piece of threaded rod before the real installation shows how the driver behaves at each speed.
Handles, Ratcheting Mechanisms, and Compatibility
The handle is where nut driver sets differ the most in feel. A screwdriver-style handle gives the set its hand-driving mode, and some handles add a ratcheting mechanism so the driver stays on the fastener while the grip is repositioned. Ratcheting saves time on long runs of nuts, but it adds moving parts, and some users find the mechanism unnecessary on a tool that is mostly used with a power driver.
A complete set with a handle typically lists around $50, while the drivers alone run closer to $30, so buying the drivers only makes sense when a compatible handle is already on hand.
Compatibility With Other 1/4 Inch Hex Tools
Most nut drivers use a 1/4 inch hex shank, which means they can be used with bit holders, magnetic bit extensions, and other handles that accept hex bits. Some handles add a retention cut that is specific to the manufacturer, and that cut can keep the handle from seating on a standard 1/4 inch hex bit. If you plan to mix brands, test the fit before relying on it.
For crews that prefer compact carry, folding nut driver sets trade a little leverage for portability, and they make sense when the drivers live in a pouch rather than a tool box. A folding set rarely includes a ratcheting handle, but it keeps the whole size range in a single pocket.
Storing the Set So the Sizes Stay Together
Loose nut drivers disappear fast on a jobsite. Sets with a molded tray or a rail keep the sizes organized, and color-coded shafts make it possible to grab the right size without reading the stamp. Replacement drivers are sold separately for most systems, which is useful when one size wears out before the rest.
Magnetic Retention and Fastener Control
Built-in magnets are the difference between a nut driver that holds a fastener and one that drops it into a wall cavity. A magnetized driver keeps the nut or screw seated on the socket while the operator lines it up, which matters for overhead work, confined spaces, and long reach applications where a second hand is not available.
How Magnetized Drivers Behave
- The magnet holds ferrous fasteners on the socket tip during placement.
- The driver can pick up a nut from a tray or parts bin without touching it.
- On hollow shafts, the magnet sits near the socket so the fastener stays in place while the driver seats it.
Magnetic retention works only with steel fasteners. Brass, stainless, and aluminum hardware will not hold, and a magnetized driver can pick up metal chips and filings that then get pressed into soft materials. Magnetic nut driver systems earn their place in production fastening work, where every dropped fastener costs time and a trip down the ladder.
A quick check before buying: hold the driver near a fastener in the store and see how firmly the magnet holds. Strong magnets hold the nut for vertical and overhead work; weak magnets are barely useful on a bench.
Building a Practical Nut Driver Setup
Putting together a nut driver setup is a short exercise in matching tools to work. The steps below work for a first set or a replacement set.
- List the hex fastener sizes your crew touches in a typical week, then buy a set that covers the full range.
- Decide whether the work involves threaded rod or long bolts; if it does, choose hollow shafts.
- Check the impact rating if the drivers will run under an impact driver or a drill.
- Pick a handle style that matches how the crew works: ratcheting for speed, a plain handle for simplicity.
- Confirm the drivers fit the handles and bit holders you already own, then store the set so the sizes stay together.
The same trade-offs appear when comparing precision screwdriver sets: driver types, sizes, and set economics decide what actually earns space in the box. A set that covers the fasteners on your jobs and works with the power tools you already own is the one that will still be in the truck at the end of the season.