Quality Control

Specialist Refractory Services Limited was established in 1984 to manufacture refractory mould materials for the casting of non-ferrous metals by the lost wax casting process. Over the years the company has developed into a leading specialist in the use of gypsum plaster for non-ferrous metal casting.

As a company we put QUALITY first and believe that excellence is not a skill, it is an attitude. We apply this attitude to all aspects of our company from the purchase of raw materials right through to the customer application of our products. We take great pride in offering world class products, customer service and technical support.

We have a strong culture of “lessons learnt” within the company which means that continual improvement and product/process development is at the core of what we do. It is “not by chance” that we, as a group, are the largest manufacturer of investment casting powder in the world manufacturing and supplying in excess of 50,000 metric tonnes per annum, which is in excess of 55% of the world’s consumption. We have worked very hard to provide the best products and technical service in the market at a competitive price and delivered product on time.

The company is Accredited ISO 45001:2018 and ISO 9001 Quality Management and the raw material & finished product testing regimes and product quality assurance system are regularly audited




Internal Routine Testing On Finished Products

In process testing include Set Time, Rise (loss of entrapped air under vacuum), Flow time & Viscosity. If any of these specifications are not met during batch processing control, additions are made to the batch and it is re-blended and tested again.

Every batch of investment plaster that is manufactured undergoes a full casting trial as a Factory Acceptance Test (FAT). Subject to this FAT passing and all other parameters being within specification, products are then released for despatch.

At the request of the customer Certificates of Conformity (C of C) can be issued detailing actual batch test results versus product specification for the following parameters: Gel Time, Gloss off,Viscosity and FAT Casting Results.

A 2kg sample of each batch of investment plaster produced is retained and stored for 12 months.


Pour Test

Setting Expansion Test

Sieve Test