One is the handle, the other is the grip
A socket set and a ratchet are not rivals. They are two halves of one system. The ratchet is the handle with a gear mechanism inside that turns things. A socket is the cup-shaped piece that slips over a nut or bolt head and grips it. You need both to loosen or tighten a hex fastener this way. A “socket set” is normally sold as a collection of sockets, usually with a ratchet and a few accessories in a case, so the name sometimes refers to the whole kit.
This explains most of the confusion. Someone shopping for a “ratchet” may be buying only the handle, and someone shopping for a “socket set” may get the handle included or not, depending on the listing. Reading the contents list is the surest way to know.
What a ratchet does
Inside a ratchet head is a gear and a small spring-loaded pawl, a catch that lets the handle turn the gear one way while slipping over it the other way. A small switch or lever selects the direction. This means you can tighten a fastener by swinging the handle back and forth in a small arc without removing the socket each time. In a cramped space where you can only swing the handle a short distance, this is the main benefit.
The ratchet’s square drive stud sticks out of the head, and the socket clicks onto it. Ratchets differ in the number of teeth in the gear. A finer-toothed gear needs less swing between clicks, which helps in tight spots, though very fine mechanisms may be less robust. Handles also vary in length, in whether the head is fixed or flexible, and in whether a quick-release button lets you pop sockets off quickly. Ratchet handles are covered in more detail in a separate article.
What a socket does
A socket has two ends. One end is a square hole that fits the ratchet’s drive stud. The other end is a cavity shaped to fit the fastener, most commonly a hex (six-sided) pattern. Sockets are measured by the size of the fastener they fit, in metric or inch units, and by the drive size of the square hole. Mixing up metric and fractional sizes is a common mistake, and metric versus SAE sizing is explained on its own.
Common socket variations include:
- Shallow sockets for fasteners with little protruding thread.
- Deep sockets for a nut on a long bolt or a bolt in a recessed position.
- Six-point and twelve-point versions. Six-point sockets generally grip the flats of a fastener better and are less likely to round it off, while twelve-point sockets are easier to slip onto a fastener from various angles.
- Impact sockets, made for use with impact tools and typically thicker-walled. Regular chrome sockets should not be used on impact wrenches, since they are not designed for that kind of loading.
Drive size: where the two meet
The “drive size” is the square-hole size on the socket and the matching square stud on the ratchet. Typical sizes are 1/4-inch, 3/8-inch and 1/2-inch, with larger ones for heavy-duty equipment. A socket will only fit a ratchet of the same drive size unless you use an adapter, so drive size is the thing to check first.
Small drives suit small fasteners and tight places. The larger the drive, the stronger the tool, and the bigger the fasteners it can handle. Choosing among socket drive sizes depends on the kind of work. For general household and light automotive work, 3/8-inch is commonly regarded as a versatile middle size, though your own jobs may call for something else.
What else comes in a socket set
Besides the ratchet and sockets, a set often has:
- Extensions, which are short bars that add reach between the ratchet and the socket.
- A universal joint, which lets the socket turn at an angle.
- Adapters, which step up or down between drive sizes. Using a large drive on a small socket can overload it, so adapters should be used carefully.
- Sometimes spark plug sockets, bit sockets and a case or tray.
When you shop, a set’s value depends on whether the sizes cover what you actually work on, rather than only the total piece count. Some sets are sold as just sockets or just wrenches, so check what is included.
What a ratchet cannot do alone, and what sockets cannot do alone
A ratchet by itself cannot grip a fastener. It has only the square stud. A socket by itself can be turned by hand or with another driver but offers almost no leverage. Together they give leverage, speed and good grip.
Another point: a ratchet is built for speed, not for extreme force. If a bolt is badly stuck, putting a long pipe on the handle can damage the internal mechanism. A breaker bar, which is a solid handle with no ratchet gear, is the better choice for stubborn fasteners. Penetrating oil can also help with rusty ones, though it should be used following its label directions and with good ventilation.
For fasteners that must be tightened to a specific specification, a torque wrench is the correct tool; a standard ratchet does not measure how tight you have gone.
Safe use
- Choose the correct size so the socket seats fully on the fastener. A loose fit rounds the corners.
- Pull the handle toward you instead of pushing it away where possible, since a slip is less likely to throw your hand into something sharp.
- Keep sockets and ratchets clean and dry, and wipe off oil or grease so your hand does not slip.
- Do not use hand sockets with power tools unless they are rated for that.
- Wear eye protection when working under a vehicle or around rusty parts.
This is general information; always follow vehicle and tool manuals.
A quick way to remember
The ratchet is the engine of the system, a handle that turns. The socket is the part that touches the fastener. When someone says they need a socket set, they usually mean a ratchet plus several sockets. When someone says they need a ratchet, they usually already own sockets, and they need a handle of the right drive size.