How to choose sockets and ratchets

A practical ToolBuyer buying guide to comparing the details that matter before ordering.

Start with the fastener

Match the socket opening to the nut or bolt. The drive size is the square connection between the socket and handle; it is not the size of the fastener. A 17mm socket and a 1/2 in drive refer to different parts of the tool.

Choose a drive size

Common 1/4 in, 3/8 in, and 1/2 in drives suit different access and workload requirements. Larger does not automatically mean better. Check that the ratchet, socket and extension share the same drive, and use adaptors only within their stated limits.

Check socket depth and profile

A deep socket can reach a nut on a projecting stud, while a shallow socket can be easier to use in a restricted space. Hex, bi-hex, Torx, and spline profiles are different. Match the fixing accurately before applying force.

Impact use needs an impact-rated socket

Do not assume a chrome hand socket is suitable for a powered impact wrench. Use accessories specifically rated for the tool and task, and follow the equipment instructions.

A ratchet is not a torque wrench

A ratchet helps turn the fastener. A torque wrench controls tightening to a specified torque when used correctly. Use the vehicle or equipment specification where torque matters; a torque multiplier or angle gauge is not automatically a substitute for a calibrated torque wrench.

Compare the contents

Check individual sizes, extensions, adaptors and the supplied case. A large piece count can include small bits or accessories and may still omit the size you need.

Compare the relevant ToolBuyer range. Check the current product listing for exact specifications, compatibility and supplied contents.