William Lee Ltd

Callywhite Lane
S18 2XU
United Kingdom

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Today 09:00 AM - 05:30 PM (Currently Closed)
Fax: 01246 417165
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William Lee Ltd is one of the UK's leading producers of high quality castings in S.G Iron, Austempered Ductile Iron, Grey Iron and SiMo. From the raw casting to the finished component, we have the facilities, skills and experience to meet the diverse requirements of the most demanding industrial sectors. We have been involved in the production of medium to high volume repetition castings for over a century, giving us the experience and expertise to take on most projects. At our facility in Dronfield we utilise state-of-the-art Disamatic D2013 vertical moulding and DF/Disa horizontal moulding plant to produce castings weighing between 0.1kg to 35kg. Our annual manufacturing capacity extends to 35,000 tonnes. A general policy of continual improvement in design and manufacturing processes ensures William Lee customers only ever receive the highest grade components. We implement strict quality control procedures which are fully approved to ISO 9001 standards, and we also hold accreditations to the Environmental Standard ISO 14001.


William Lee Ltd has three separate foundries with a total output capacity of 35,000 tonnes. We are currently in the process of extending our capacity to 50,000 tonnes per annum, which should allow us to take on an even greater variety of moulding projects. Our foundries contain facilities for both horizontal and vertical moulding, the processes of which can be seen on the William Lee website.

Core Making

We are able to produce over 300,000 cores per week thanks to our extensive range of core making facilities. This number is made up of both hot-box (shell) and cold-box cores. To produce a hot-box core we inject resin-impregnated sand into a heated metal core box. The resin hardens as it heats up, meaning that any sand that comes into contact with the surface of core box will also harden. Once this process has taken place, the remaining sand - which is insulated from the heat by the crust that has already formed - will simply drop out, leaving a hollow hardened shell. Cold-box cores are made by mixing a two-part resin with sand to form a solution which, after being blown into the core box, is cured through a reaction with Amine gases which are also blown into the core box. The outcome is a solid core.

A.D.I Heat Treatment

We are one of the few European foundries to have access its own Austempering plant. This consists of 3 preheat furnaces, a quench salt bath and a holding salt bath. Austempering is an isothermal heat treatment process which enhances the strength and wear-resistance of ductile iron, whilst also  retaining the vital impact resistance and ductility for which the material is valued. Austempered ductile iron is also 10% lighter than steel. If you would like to find out more about our A.D.I Heat Treatment capabilities, please visit the William Lee Ltd website.


William Lee Ltd undertakes an enormously diverse range of work, so it's essential that we have the right equipment and the right engineers to ensure that any project is competently processed. Every part that we manufacture is followed through with a route card to ensure that every operation is carried out to the exact specifications of the customer. Our fabrication facilities include robotic  fettlers, CNC lathes, auto grinders, grinders, presses, hand fettlers, and a wide range of specialist application equipment.

Sand Plant

High quality sand is vital for mould production. The use of sub-standard sand often results in dimensional problems and poor surface finishes. Each of our foundries has its own dedicated technician monitoring sand at all times to ensure it meets the required standard. It is regularly tested for moisture content, green strength, permeability, and compaction. Most of the sand that we use is reconditioned and used again - this is both cost-effective and environmentally friendly.


William Lee Ltd has always remained dedicated to providing an exceptional standard of service for its customers. We understand their needs and expectations, and always provide them with high quality products that conform to their specifications. To guarantee the integrity of our products, we implement strict quality control systems which are fully accredited to ISO 9001:2008 standards. This quality system has been formulated to demonstrate our ability to consistently provide products that meet and exceed applicable regulatory requirements. These processes are subject to continual improvement in order to satisfy the ever-increasing standards of excellence demanded by global industry.


William Lee Ltd produces a variety of cast iron materials from its state-of-the-art facility in Dronfield, including Austempered Ductile Iron (A.D.I), SiMo, Grey Iron and Spheroidal Graphite (S.G). Over a century’s worth of experience in the production of cast iron means that we can guarantee all grades meet and often exceed the required specifications. All materials undergo meticulous testing at regular intervals and at various stages of the production process to ensure quality. 

There are many advantages of using an iron casting. Firstly, a highly fluid molten state means that it is easy to cast. It’s also easy to machine, and has excellent damping and bearing properties. And though it is 10% lighter than steel, it still retains outstanding strength, and is highly resistant to fatigue.


William Lee Ltd can improve your logistics, simplify communications and potentially reduce costs by taking on responsibility for the fabricating and finishing processes. These can either be completed by our sister company, CNC Speedwell, or can sub-contracted to various approved machinists. We a have a large database of UK and European sub-contractors that enables us to select the best partner for the job. Finishing processes such as galvanising, sheradizing, electrophoretic painting, powder coat painting and zinc plating can also be completed through the use of various known and reputable sub-contract finishers.


We are able to perform all but the most specialised testing processes in-house thanks to our comprehensive range of test and inspection equipment. 

Dimensional analysis is carried out using a state-of-the-art Mitutoyo Coordinate Measuring Machine.

Tensile testing, hardness testing and Eddy Current testing are processes used to evaluate mechanical

Metallurgical analysis is carried out using ARL metals analysers, carbon/sulphur determinators, image analysers, Aquinto image capturing systems and ultrasonic testing.

We use magnetic particle inspection and ultrasonic tests to detect defects within the materials.


We operate a Total Productive Maintenance System (TPM) which enables us to carry out more than 200,000 inspections on plant and equipment per annum. This ensures that all of our facilities are up the demanding standards of modern industry. The TPM system also responds to plant breakdowns, following problem solving techniques such as 5 WHY, Kaizen and Cause & Effect to minimise downtime. 

William Lee Ltd also implements predictive maintenance techniques that allow us to assess the condition of every bearing on site, and also to analyse gearboxes, hydraulic oils, extraction systems, lighting levels, tool vibration levels and more.


William Lee Ltd utilises state-of-the-art 2D and 3D CAD software for its design processes. Programmes include AutoCAD 2010, the industry standard draughting tool, DelCAM, a leading toolmakers design tool, and Solidworks, the very latest 3-Dimensional modelling tool. 3D CAD modelling is increasingly being used in place of 2D drawing, largely due to the fact that 3D designs can be integrated into the manufacturing process. 

We also use Solidification Software to locate problem areas in the casting during the design stage, which significantly reduces waste during the manufacturing stage. If you would like to find out more about our design capabilities, or if you need to discuss your design ideas with our experts, just give us a call on 01246 416155.

Forging/Fabrication to Casting

In many cases castings can offer distinct advantages over other metal forming processes, including improved mechanical characteristics, reduced production costs and greater design flexibility. In recent years, William Lee Ltd has undertaken numerous innovative projects in which existing components have been modified through the consideration of alternative materials and design and manufacturing processes. This has been achieved without compromising the overall quality and application suitability of the end product. Typical examples include the conversion of steel pressings or fabrications to cast components and conversion of steel castings, forgings and non-ferrous materials to A.D.I or S.G Iron. You can find out more about the benefits of these processes by visiting the William Lee website.



Registration Number: 02575974
VAT Number: n/a
Registered at Companies House:23 January, 1991 (31 years and 6 months ago)
No of Employees: 251-500
Annual Turnover: 20-50m
Parent Company: Castings Plc
Company Type:
  • Manufacturer
  • Service Providers

Opening Times

Monday 09:00 AM - 05:30 PM
Tuesday 09:00 AM - 05:30 PM
Wednesday 09:00 AM - 05:30 PM
Thursday 09:00 AM - 05:30 PM
Friday 09:00 AM - 05:30 PM
Saturday Closed
Sunday Closed

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Additional Information

Company Certifications

ISO 9001:2015 - Quality management systems – Requirements
ISO 14001:2015 - Environmental management systems – Requirements with guidance for use

Financial Information

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