Engineering & Finishing

CNC & Conventional Machining

To provide our customers with a complete one stop engineering solution we took the steps to invest and develop the machining side of our business and now house both 4 and 5 axel Haas CNC machining centres. These centres undertake high precision turning, milling, drilling and surface grinding as well as being able to produce full detailed dimensional reports.

As well as highly efficient and accurate CNC machining we do operate conventionally as well with an array of machinery including lathes, pillar drills, radial drills and a horizontal miller.

Our team of skilled machinists in this department can provide accurate machined finishing to your castings whatever it may be.

Shot Blasting

After careful hand finishing, all our castings have the option of a shot blast finish – using stainless steel shot, this service provides a uniform surface finish and is ideal for pre-treatment prior to further polishing, painting or powder coating

As well as offering this service on our castings the shot blasting facility also gives us the ability to restore previously supplied items such as bronze plaques that weather over time and lose the shine – a quick spin in the Sisson rotary table can bring these tired looking items back to life.

Polishing & Plating

Various options are available to our customers post casting – two such frequently required surface treatments are polishing and plating.

Whether it be high mirror finish polishing or satin finish our industry served silversmith polishers can provide this service.

Plating is a sub-contracted service we offer where castings can be chrome or brass plated to not only offer a high quality surface finish but also additional protection to the castings.

Powder Coating

Our powder coating facility operates daily with our self-supply Conservatory stock – however this is another option in our “one-stop-shop” that we offer when supplying castings – we use high grade paints and offer all RAL colours in both gloss and matt finishes.

Durable and pliable but with a lower environmental impact than traditional paint finishes this hard wearing finish is both attractive and scratch resistant often making it the preferred choice for cast products.

Heat Treatment

The hardness of a casting can be further increased through a heat treatment process – not all materials lend themselves to this process however some aluminium alloys and High Chrome Irons both show significant hardness and machinability improvements once treated.

Using conventional methods such as vacuum treatment and oil/water quenching we gradually treat the castings to various AMS and ISO standards and once complete can offer full hardness and crack detection testing.

Other heat treatment services we can offer include Flame Hardening which is often used for impeller vanes to give additional strength and Annealing which is typically used to reduce material hardness for ease of machinability and to help eliminate internal stresses.

Resin Impregnation

Vacuum pressure impregnation is a reliable method used to seal porous castings and other materials without impacting on the functional or dimensional characteristics of the material.

Impregnation has been in commercial use for over 60 years and continues to be the preferred method for ensuring pressure tight components in fail safe applications. The aerospace, automotive, food processing and oil and gas industry use vacuum impregnation to improve the quality of their base castings, conserve resources and reduce scrap.

Technical Capabilites

Casting Capabilites

CHC Sheffield Lost Wax Casting
CHC Sheffield Sand Casting
CHC Sheffield Pressure Die Casting
CHC Sheffield Sand Casting
© Copyright 1948 - C.H. Coward Limited.

540 Ecclesfield Road, Sheffield, S5 0DJ

Company number 00456385

VAT GB 172 41 8077


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