Dressing Plates

Bonanomi manufactures cast iron dressing plates in G25 and G30, custom-made, in a single piece up to 7000x2500 mm. Each plate is machined in accordance with DIN 876 standards and accompanied, upon request, by an installation service and a certificate of conformity.

From the foundry to delivery, every stage is planned together with the customer to ensure flatness, rigidity and long-term stability.

G25 or G30 Cast Iron Dressing Plates

The Dressing Plate is a G25 or G30 Grey Cast Iron Base used in precision mechanics to inspect or mark out workpieces of any material and shape.

It consists of a perfectly flat surface known as the plate, which complies with DIN 876 Standard concerning the flatness of machined surfaces. The underside of the plate is formed by ribs that increase the rigidity of the base according to the load the structure will need to bear. The machining of the surface and lateral bands is planned with the customer, so as to obtain benches on which scribers or measuring elements can slide.

Difference Between Cast Iron G25 and G30 in Dressing Plates

Pearlitic lamellar cast iron provides excellent thermal stability, which translates into consistent flatness over time regardless of temperature variations in the production environment. This characteristic makes surface plates suitable for every stage of the process: from semi-finishing to final inspection.

G25 cast iron has a hardness of 180–200 HB and a tensile strength of approximately 260 N/mm², making it ideal for applications with medium loads and high machinability requirements.

G30 cast iron reaches a hardness of 190–230 HB and 300 N/mm² tensile strength, and is recommended for heavier-duty applications or where greater structural rigidity is required.

How are Bonanomi's Dressing Plates made?

Bonanomi Dressing Plates can be produced using three types of mouldings depending on production requirements:

Natural model
Model in Core Boxes
EPS model

At the end of the mould preparation, the Cast Iron is poured.

The process ends with careful slow cooling of the casting in the stirrups, in order to obtain good relaxation of the internal tensions caused by non-homogeneous masses present in the structure of the casting (difference in thickness between ribs and plate), maximum workability and excellent stability of the finished piece.

The production of the Dressing Plates starts with single piece sizes from 1000x800 mm up to 7000x2500 mm. Modularity is a fundamental feature to adapt to any construction layout.

Levelling accessories and other services

As accessories for levelling, Bonanomi supplies Support Columns or Electro-welded and Painted Tubular Steel Supports in various sizes, depending on the customer's needs, all with the possibility of adjustment by means of a micrometric screw.

Our company also offers an installation and assembly service, providing, at the end of the work, test certificates and certificates of conformity regarding the work.

As an alternative to the standard precision mechanics products listed in the catalogue, Bonanomi can manufacture any dimensional encumbrance, using any material, in order to better comply with the needs and requests of the final customer.

Not only Dressing Plates: discover other Bonanomi products

Not only Dressing Plates: discover other Bonanomi products!

In our Precision Mechanical Workshop, we also manufacture:

We also offer Third Parties Mechanical Processing (Outsourcing Services).

Frequently Asked Questions

Is it possible to order a custom surface plate?

Yes. Bonanomi manufactures custom surface plates in any size, up to 7000x2500 mm in a single piece. You can specify the material, surface finish, the presence of slots or holes, and the finishing of the lateral bands. Each project is defined directly with the customer.

Do Bonanomi surface plates come with certification?

Yes. At the end of production and, if required, installation, Bonanomi issues a certificate of conformity and, in the case of the assembly service, a test certificate documenting the positioning and levelling operations carried out.

How is the flatness of a surface plate maintained over time?

Lamellar cast iron ensures high thermal stability, which minimises dimensional variations over time. To preserve flatness characteristics, it is advisable to protect the surface from impacts, clean it regularly with non-abrasive products, and periodically check the levelling via the micrometric screw on the support feet.