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Growing by Inches

Growing international demand for inch size threads is encouraging UK suppliers and manufacturers of standard parts and components to broaden their range. The variety of inch thread products available at WDS is expanding to supply customers from North America and around the world.

John Marshall, Technical Manager, WDS Component Parts Ltd, explains the reason behind the growing product range with inch size threads.

Challenges behind standardisation between Britain, the USA and Canada, evidenced during the intense manufacturing demands of World War Two, led to the creation of the Unified Thread Standard (UTS) in 1949. Based on inches, the standard included Unified Coarse (UNC) and Unified Fine (UNF) as the most common examples. Eleven years later, the International System of Units was created as the modern form of the metric standard. With origins in Continental Europe, it remains the only standard of measurement, threads included, in almost every country in the world.

While the basic profile of UTS and metric threads are the same, the difference in major diameter and pitch (the variation between the thread peaks) removes the potential of compatibility. Within UTS, UNC is more commonly used for general engineering applications while UNF, with its increased thread per inch ratio, is preferred for very small applications and those requiring greater precision and strength, such as aerospace applications.

Despite British involvement in the creation of UTS, the UK developed greater ties with Europe and generally adopted the metric thread system. However, following Britain’s departure from the European Union, the potential of increased trade with wider partners including North America has re-emerged. Inch dimension thread sizes don’t just mean America and Canada however, as South America, China and Commonwealth countries are among those with demand for the standard, often in addition to metric.

One of the reasons WDS already supplies inch thread dimensions is to fulfil demand of UK or international OEMs designing products for North American markets. We are often required to provide single or low volume numbers of parts as spares or replacements in addition to the higher volume required for OEMs.

Increasingly however, American, Canadian and South American OEMs are buying direct from our Leeds, England site. First, the price has to be right, as does timescale. We’re able to be competitive even against large scale American-based suppliers because of our large stock, our ability to source large quantities or less frequently requested items, as well as our in-house manufacturing capability. This also contributes to quick delivery and our daily overseas despatch for stock items. Despatch is usually by sea freight, although items can also be shipped by airfreight if the weight is low or if the customer has urgent demand.

As we specialise in standard and component parts, our level of customer service is more personal, detailed and application-specific than most competitors on the global stage. Starting with our website, wdscomponents.com, for each one of our 20,000-plus parts we provide a detailed product specification including 2D and 3D CAD drawings, as well as an increasing range of colour drawings, so the customer can identify what the component in question looks like. We’ve also just released a new catalogue, Inch Dimension Components from WDS, which presents the full and expanded range of standard parts and machine components available in UNC and UNF inch thread dimensions. The catalogue can be located on wdscomponents.com in the media section of the website.

We’ve formed partnerships with many companies because of the direct level of customer service and engineering advice we provide. This is particularly invaluable when a customer begins with us from new when they need clarification to ensure that the exact specification is provided. We’re increasingly attracting North American and global customers as a result of this approach. Our technical team has in depth knowledge of the components and can quickly respond by e-mail or telephone regarding the specification and suitability of the item for the application in question.

A recent example involved an American customer who required a large number of castors. We received their drawings, added our product dimensions and returned it to them to demonstrate fit. That’s just an example of a task which we regularly fulfil but it’s not something that all component suppliers can do, especially if the supplier is a very large, general industrial retailer without the same level of expertise.

Some of the new products available in inch sizes include T-knobs and wing knobs, typically used in machine build and with applications across industry. They’re now available in stainless steel and product quality is another reason why our return business is high – product samples are also provided prior to purchase. These new components join a wide range of existing inch-size products, from nuts and screws to levelling feet. In addition to UNC threads, UNF dimensions are also available for components used for specific industries, such as bicycle manufacture, which requires more precise adjustment. We provide clamping levers for example, which are used as part of the quick release skewer mechanism within a bicycle wheel hub.

WDS can also design and manufacture bespoke parts in UNC or UNF dimensions on request. Any product not currently available in UNC or UNF can also be developed by WDS to fit demand.