Discover our wide range of wrenches online now at Cromwell. We stock high-quality wrenches to suit all your working needs, including adjustable wrenches, wrench sets and jaw and knurl replacement kits. Our wrenches are constructed from durable materials, like drop forged chrome vanadium steel for strength you can rely on.

Our range of wrenches has been specially selected from well-known, quality brands, like Yamoto®, Facom®, Bahco® and Eclipse Blue® to provide excellent quality at great prices.

What are wrenches?

In the UK a wrench is often referred to as an adjustable spanner, where the jaws can be adjusted to grip and apply torque to fasteners, like nuts and bolts. Constructed in a range of sizes for different applications, the lower jaw is adjusted using a thumb screw at the neck of the tool. In this way, a single wrench can be used for multiple jobs.

When are wrenches used?

An extremely versatile hand tool, wrenches are widely used in a range of industries. They appear frequently in automotive garages and are a regular in a plumbers' tool kit. Used to apply torque to fasteners, a wrench is also a popular tool on construction sites and DIYers' workshops.

Wrench types

Most types of wrench have an adjustment feature to provide a strong grip in multiple applications. An extremely flexible tool, it can be used for gripping, tightening and loosening fittings like nuts and bolts or other similar fasteners in car engines during maintenance and repair.

• Adjustable wrench   -   One of the most popular wrenches, the adjustable wrench is wrench is often referred to as an adjustable spanner, where the jaws can be adjusted to grip and apply torque to fasteners, like nuts and bolts

• Strap wrench   -   A self-adjusting tool, this wrench features a flexible jaw with teeth for a strong grip.

• Pipe wrench    -   Adjustable using the same method as an adjustable wrench, this wrench closes from the top and is used by plumbers on pipes. Self-clamping, it allows for single-handed operation

• Pliers wrench   -   Used for gripping and bending, this tool is more pliers than wrench. The parallel jaws grip with zero pressure to allow for working with delicate materials

• Chain wrench   -   Featuring a flexible chain at the end of a ratchet handle, this wrench grips using small teeth along the length of the chain and is an ideal choice for heavy-duty projects

Considerations when choosing a wrench

Dimensions - the size of the handle is important when handling and exerting force on a fastener. The wrench must be easy to grip and use.

Application - when in regular use in a mobile toolkit, the weight of the tool must be taken into consideration, while this isn't so much an issue for a DIY enthusiast.

Jaw width - this ties in with application in knowing the frequent sizes you'll need on hand. The most used are 6in. 8in. and 12in wrenches.

• **Material **- wrenches are often made of steel alloy or hardened vanadium steel for a heavy-duty tool. A chrome or nickel-plated finish will protect against corrosion.

Adjustable strength - when buying an adjustable wrench, pay attention to the quality of construction and the strength of the scroll wheel. Some lower quality designs will easily adjust and lock the jaw into place but won't hold it there.

Wrench jargon buster

We want to make it easier for you to find the wrench you want, so we've put together a brief outline of an associated safety standard to keep you in the know.

What does the standard BS ISO 6787:2018 mean?

BS ISO 6787:2018 outlines the technical specifications, including the dimensions of adjustable wrenches.

Let's break it down...

• BS - This was published by British Standards (produced by the BSI group)

• ISO - An adjustable wrench must meet the safety standards outlined by the International Organization for Standardization

• 6787 - This is the assigned legislation number

• 2018 - This is the year the safety standard around adjustable wrenches was updated. It now specifies test conditions for tool performance and outlines the dimensions and admissible clearance of the jaw adjustment


What is the best material for a wrench?

Wrenches are subject to a lot of torque and thus are made from strong alloys like chrome or vanadium steel. Cheaper tools are sometimes made from molybdenum steel which is an ideal alternative for light-weight applications.

How do I know what size wrench to use?

Measure the diameter of the fastener (nut or bolt) and multiply this by 1.5. This will give you the jaw size required to adjust the fastener as desired.