Different Kinds of Wrenches

The main function of a wrench is to rotate a bolt head or nut. Choosing the right wrench from the many types available depends on the size and design of the fastener. It may also depend on the accessibility of the fastener.

As you'll soon discover, there is an extensive variety of wrenches available, ranging from open-end and box-end wrenches to combination, adjustable, and even pedal wrenches.

How to Properly Use a Wrench

Using a wrench may appear simple, but doing it properly can make a significant impact. Start by selecting the correct size wrench for your nut or bolt; a tight fit on the wrench head is essential. If it’s too loose, you risk damaging the edges, which will make it harder to turn.

For basic turns, position the wrench so that it forms an 'L' shape with the bolt for extra leverage. Then, rotate the wrench clockwise to tighten and counterclockwise to loosen – you can always remember the classic rhyme, 'righty tighty, lefty loosey.'

If the fastener is very tight, apply steady and consistent force instead of jerking the wrench. Always pull the wrench towards you to prevent injury in case it slips.

Various Types of Wrenches

Here are some of the various types of wrenches you can choose from:

Box-End Wrench

A box-end wrench (also known as a closed-end wrench) is ideal when there's enough space to place the wrench's mouth around the fastener. These wrenches come in 6- and 12-point versions to match the number of sides on the fastener. Hexagonal fasteners, which have six sides, are the most common.

Open-End Wrench

This type of wrench is used for turning fasteners in spaces where a box-end wrench cannot fit around the fastener. It can also be used to help loosen fasteners.

Combination Wrench

A combination wrench is a highly adaptable tool that cleverly merges two types of wrenches into one. On one side, it has a box-end, a closed loop designed to securely grip hexagonal or square nuts, making it perfect for stubborn, difficult-to-loosen fasteners. The other side features an open-end, a U-shaped design ideal for quickly unscrewing the nut once loosened [source: Tameson].

The versatility of a combination wrench makes it a favorite among DIYers and professionals alike. Available in both metric and standard sizes, it accommodates a wide variety of bolt sizes.

Adjustable Wrench

Also known as a crescent wrench, an adjustable wrench can be used on fasteners of various sizes. However, its flexibility comes with a drawback: it is less stable than a fixed-size wrench and may risk injury or damage to the fastener if not used carefully.

An adjustable wrench should be used only when a wrench of the correct size is unavailable.

Torque Wrench

A torque wrench is a highly accurate tool designed to control the amount of force applied to a bolt, ensuring proper tightness and preventing over- or under-tightening. This is especially important in tasks like engine maintenance. Like a socket wrench, a torque wrench features a head, an adjustable socket, a rotating handle with measurement indicators, and a locking nut at the bottom.

To operate a torque wrench, loosen the bottom nut, set the handle to the desired torque setting (measured in lb-ft, lb-in, or Nm), attach the socket, and rotate it to tighten or loosen the bolt. The wrench will notify you when the set torque is reached. Always reset it to the lowest setting after use to maintain accuracy [source: SkillCat].

Socket Wrench

A socket wrench, often called a ratchet wrench, is an essential tool for effortlessly turning fasteners with accuracy. These wrenches fit directly over the fastener, making removal safer and more efficient compared to other wrench types.

The secret behind a socket wrench is its ratcheting mechanism attached to the handle. This smart design enables you to tighten or loosen nuts and bolts by simply pushing or pulling the handle, eliminating the need to remove and reposition the wrench after each turn.

Socket wrenches are particularly useful in tight spaces where movement is restricted. Sockets come in both standard and extended depths, and extensions are available to make removing fasteners even easier [source: Lowell Corporation].

Pipe Wrench

The pipe wrench, designed for use with softer pipes like black pipe, is a vital tool with an adjustable jaw and serrated teeth to ensure a firm grip on pipes of various sizes. It consists of a handle, adjustable nut, fixed jaw, and an adjustable jaw.

To use it, hold the end of the handle for leverage and adjust the nut to fit the pipe size—turn clockwise for smaller pipes and counterclockwise for larger ones. The adjustable jaw on a pipe wrench moves up and down, allowing for easy positioning. With its longer design, the pipe wrench offers extra leverage and grip, making it ideal for tightening or loosening pipes effectively [source: SkillCat].

Allen Wrench

The Allen wrench is a distinctive L-shaped tool known for its hexagonal head, which fits into bolts with hex-shaped sockets. It features two hexagonal ends, each offering its own set of benefits.

When you insert the wrench vertically into a bolt, you'll have less leverage, which may make turning harder but can be useful for reaching tight areas. However, to loosen really stubborn bolts, use the wrench at a 90-degree angle to the nut. This position increases your leverage, making it much easier to loosen the bolt. Remember, the longer side of the wrench provides greater leverage [source: SkillCat].

Strap Wrench

The strap wrench is a versatile and innovative tool, perfect for gripping and turning objects without causing harm. Instead of the typical metal jaws, it uses a rubber strap to create friction and hold items securely. This design prevents scratching delicate surfaces, making it ideal for use with sensitive materials.

Most strap wrenches feature handles for a firm grip, but some models are designed to fit onto the square drive of ratchet wrenches. Its ability to adjust to various sizes makes it useful not only for professional jobs but also for everyday tasks, like opening stubborn jar lids [source: Tameson].

Pedal Wrench

The pedal wrench is a specialized tool used by cyclists and bike mechanics. It is designed specifically for installing or removing pedals from a bicycle. What makes this wrench unique is its slim design, allowing it to easily slide between the pedal and crank arm, where space is often limited.

Typically, one end of the pedal wrench is angled, providing additional leverage to effectively loosen or tighten pedals. The other end is usually flat, making it convenient for use in different positions [source: Wikibooks].

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