Round hole perforations provide the possibility of a large open area and strength and comes in triangular, diagonal, straight or staggered rows and also with decorative holes.

Our perforated sheets with round hole perforations are used in many applications for example:

  • for agriculture (sieves for sorting/grading of seeds and stones)
  • for the building industry
  • for the recycling industry (sorting of bulk materials)
  • Protection and ventilation sheets

Round holes are often used for acoustics and safety for the IT industry, as well as machinery construction for protection and ventilation panels.

Round holes offer a large ventilation opening with effective protection for the machine parts inside.


Round hole perforations offer an aesthetic decorative privacy shield and increases protection against the sun, and are also used for infill panels in balconies and balustrade panels.

Our vast experience as Europe’s largest producer and supplier of perforated products ensure we are your reliable and competent partner to process several types of raw materials.

Take inspiration offered by the vast number of possibilities and feel free to contact us for further information



Square holes can be supplied with parallel rows, diagonal rows or staggered rows. In addition, square hole perforations allow a high open area for applications such as ventilation and guards.

Some examples of applications for perforated sheets with square hole perforation.

Safety and ventilation sheets  

  • Ventilation and safety guards for the machine building industry
  • Ventilation and security covers for computer server chassis 
  • Facades
  • Screens for defusing and sun protection
  • Balconies and balustrades

Our vast experience as Europe’s largest producer and supplier of perforated products ensures we can produce these patterns in many different materials. 

Take inspiration offered by the number of perforation possibilities and be guided by our experts



Depending on the application requirements there are a range of slotted holes and patterns e.g staggered or straight rows, herring bone and chessboard from which to select.

Get inspiration from the numerous possibilities of perforation and please ask for any advice. 

A few applications for slot hole perforated sheets

  • Sieves for grain drying and sorting
  • Malting floors (drying-kiln and germ-hutches)

Sieves for seed processing machinery are used in both the pre-cleaning and main cleaning of grain, maize, oil seeds, legumes, malt, rice, coffee and soy beans. The cleaning and sorting of seeds (malformed, discoloured, germinated, broken, contaminated with other species or mouldy grains in seed lots) can severely impact seed quality, viability and vigour and therefore the market value.

When used for this application DNT sieves achieve high quality cleaning and accurate sorting of seeds.

Sieves for sorting machines

Sieves for revolving screen machines

  • Test sieves for grain according to DIN/ISO 3310
  • Laboratory sieves with a high degree of accuracy
  • Food processing industries
  • Fodder and grain mills
  • Recycling industries
  • Separation
  • Pellets and granulates production

DNT's screens for malting floors are manufactured to high quality standards giving reliability and effectiveness. For all processes, from drying-kiln to germ-hutches, perforated sheets incorporating slot hole perforation are predominantly used.
Brewery and Winery/Others

  • Malting floors made of steel and stainless steel for malt processing technology
  • Sieves for press houses and presses
  • Sieves for paring and polishing rice
  • Rope belt conveyers
  • Decorative applications 


 Maximum ventilation

The need for effective cooling is increasing for many technical products. Flexible solutions and innovative products like our hexagonal perforation patterns are the answer.

Our hexagonal perforation provides an extremely high open area of up to 85%. Sheets with holes of this configuration are very lightweight. The stability of the parent material is of the utmost importance to maintain the shape of a honeycomb structure. This pattern produces an appealing, timeless design suitable for current and future product applications.

The ability to control airflow can be used not only for cooling, but also the opposite effect using a targeted heat supply.

Whether it is racks or server cabinets the heat developed from the integrated systems and components must be removed to the outside efficiently, which is usually achieved by using internal fan modules. A sheet with a hexagonal perforation provides a very large open area giving optimal ventilation. Thanks to the high air flow, temperatures can be kept constant in the cabinet, whereas the other areas of the cabinet can remain obscured by non-perforated areas and are therefore protected.


The need to cool heat producing parts of machines and engines e.g. tractors and other vehicles is a traditional application for perforated sheet metal products. Depending on the chosen open area, the heat can either be dissipated or be re-circulated. Small hexagon perforated sheets can also be used as protection against insects in the engine compartment.


Applications for bridge slot sheets

Bridge slot perforation is often used for water drainage shafts and drying. Bridge slot perforation is typically used for:

  • Drying and storing solid matters and materials of all kinds
    • including herbs, tea, grain and grass seed, maize, rape and wood chips
  • Filters for fountains and drainage

The open area of bridge slot perforation is variable and depends on the depth of embossing. An embossed depth of 1.5 mm (suitable for rape seed) provides an open area of 3.7 % for ventilation. Another example are sheets with an embossed depth of 3.0 mm giving an open area of 9.1%.

Ideally seed and grain need to be stored in an area with a moisture content of less than 14.5%.
If the storage area is too moist, fungus infestation and self-heating can follow. DNT Bridge slot sheets offer you a drying solution with appropriate optimised ventilation.
With their open area DNT Bridge slot sheets allow permanent free flowing ventilation.
Our service for you

  • Guidance for the optimal storage and drying solution
  • Additional ventilation sheets or replacement of existing damaged ventilation sheets
  • Production of different material thicknesses
  • Additional fixing holes and bending as required
  • Short delivery times

If you want to secure first choice solutions for ventilation you will always find the right partner for service, ideas and quality in DNT. We are your experienced partner for industry and agriculture.


 The size of the “pockets” depend on your requirements, however the shape of the “pockets” is the most important consideration for the performance of the machine. DNT Trieur sheets are cut to size according to your specific requirements and then rolled or welded into a cylinder.

These products offer you the highest quality for sorting and separating seeds to minimize your waste. DNT Trieur sheets are made of steel or stainless steel.


The advantages of DNT Trieur sheets are:

  • Optimal number of “pockets” per square metre
  • Quality checks for ensuring pocket tolerances
  • Precision, long-life sheets
    Cleaning and sorting

Wheat, spelt, rye, barley, oat, raw rice, maize, rape and other seeds

Seeds – grain needs to be the same size and weight for processing. DNT Trieur sheets separate according to the length of the grain. To guarantee constant sizes and shapes, different sheet configurations are available. When separating round grain, DNT Trieur sheets will sift out short, round or broken grain, whilst during the separation of long grain cereals sizing can also be performed e.g. the separation of oats from wheat.

Pulses, white rice, barley, pearl barley and rye
Seed processing

Vegetable seed, pulses, sesame, linen seed, sunflower, oil seed, alfalfa, clover seed, grass seed, raw rice, maize and cereals
Bulk materials

DNT Trieur sheets are also used in the processing of fluid and industrial bulk materials such as plastic granules, wood pellets, minerals and recycling materials.

Machine productivity increases because DNT Trieur sheets minimize the space between the pockets to allow maximum throughput per hour.



DNT Premium Perforation product range

With DNT Premium Perforation, we offer products with holes the same size as sheet thickness, as well as hole sizes smaller than sheet thickness, such as:

1: Perforation with holes the same size as the material thickness (1:1 perforation) 

  • 0.50 mm holes in 0.50 mm stainless steel
  • 1.00 mm holes in 1.00 mm stainless steel

2: Perforation with hole size smaller than the material thickness

  • 0.20 mm holes in 1.00 mm stainless steel (DNT Perfocon)
  • 1.00 mm holes in 1.50 mm mild steel
  • 8.00 mm holes in 10.0 mm stainless steel

DNT is the world’s largest supplier of perforated sheets and one of the only companies to offer such an extensive range of these types of perforations from stock, as well as tailor-made solutions with other patterns and thicknesses.
DNT Premium - taking perforation to the next level...

DNT Premium Perforation gives you several advantages when compared to traditional and main-stream perforation in areas such as:

  • Durability (wearing)
  • Lifetime of screen (less replacement, fewer production stops for maintenance)
  • Cost effectiveness
  • Strength



Small holes in thick material

DNT Perfocon is an exclusive product from DNT which offers specially shaped holes that allow easy exit of particles through the screen – even with a combination of small holes in thick material. DNT Perfocon is extremely durable and long lasting compared to alternative products, giving you a more cost effective solution due to fewer production stoppages.

DNT Perfocon is a specially designed product, produced with a special technique that enables us to manufacture sheets with a thickness many times greater than the hole diameter, e.g. 0.2 mm holes in 1.0 mm stainless steel. To make sheets with holes that small in a material so hard and thick is exceptional and opens the door to an entirely different use of perforated sheets.

The properties of directional perforation enable control in airflow and sieving. The design and the angle are developed specifically to reduce the possible blocking of the holes, thereby DNT Perfocon minimizes the clogging effect. These qualities make DNT Perfocon particularly suited for the separation processes.

An example of this is when selecting a stainless steel DNT Perfocon sheet that has subsequently been electro polished, it will distinctly minimize the risk of enzymes and other particles "sticking" in the holes and reducing the flow. The electro polishing process effectively de-burrs the hole and smoothes the surface eliminating the possibility of particle blockages. We offer DNT Perfocon in mild, galvanised and stainless steel.

  • Cheese moulds
  • Distributer plates in fluid bed dryers
  • Hammer mills
  • Centrifugals

    DNT Perfocon hole sizes
  • from 0.15 mm to 1.0 mm/stainless steel
  • from 0.15 mm to 3.0 mm/mild steel 



Architectural applications

Embossed sheets are often used as decorative elements within a wide range of applications such as simple cover plates, shop decorations or sophisticated facade claddings.

The sheets are opaque and have a stylish visual effect due to their texture.
Anti-skid applications

Embossed sheets are also used for pure functional applications: for example as platforms for gang-ways and machine parts, mainly as an anti-skid application.
Depending on the form and type of embossing, the sheets can be used where various anti-skid and stiffening properties are required. Such patterns are seen in the transportation sector.

Similarly, the sheets can be used where both decorative and functional requirements have to be met, for example, indoor swimming pools and shipbuilding.


Want to be different?

You are familiar with all the usual perforation patterns, but would like to offer something new and exciting to give the final product that extra special touch!
Why not try using ornamental perforation? Experience the unconventional patterns in the world of perforation.

The extent of ornamental perforation increases month by month. Applications such as sun screens, protection screens or facade panels are just a few applications to mention and there are so many more possibilities for the use of ornamental perforated sheets.

Use our expertise in perforation!
Contact us today and we will find the right solution to your needs.



Light and cost efficient

It is a great advantage that expanded metal is not assembled nor welded, but always made in one piece.

  • No metal is lost in the expanding process, hence expanded metal is a cost effective alternative to other products.
  • Because there are no strained joints or welds, expanded metal is stronger and is ideal for forming, pressing and cutting.
  • Due to the expansion the weight per metre is less than that of the original sheet.
  • Due to the expansion a much bigger open area is possible compared to other similar products. 
  • Greater strength

The three-dimensional shape of the meshes is another advantage since the areas where the meshes meet are strong and enable the material to stand a far heavier point load than similar products or a flat sheet.



Whether it is a security, functionality or design aspect – we are your partner if it involves perforated and formed metal components for automotive applications.
We currently manufacture loudspeaker grilles, ventilation system grilles, airbag components as well as numerous other perforated parts all with precision and quality.

We can supply components ready-to-install as a combination of metal and plastics by maintaining close co-operation with our partners.

We aim to support you from product concept, through the development stage, right through to the start of production. We can undertake feasibility studies, and have our own tooling facilities which can produce prototypes to suit your requirements.

Feel free to contact us. 


White goods powered by DNT

In the production of perforated dishwasher filters we offer the complete
service from perforating and forming, including surface treatment, right up to final assembly complete with plastic rings and funnels. Our customer’s requirements are always our focus.

We have decades of experience in the manufacture of perforated sieves using highly developed technical methods. Strict quality control systems give you the certainty that you are receiving the best possible service.

Our product range for the white goods industry is wide and varied.
Please contact us for more information.


 For a long time, lamps and lighting have not only needed to be functional but also provide an aesthetic design feature that has led to some products becoming cult objects.
There are many ways of producing and achieving individual light effects!

Whether in design or product development, the building of prototypes, pre-production or mass production, we always work closely with customers to achieve their unique product. 

Our experience in working with well-known manufacturers and our knowledge of modern finishing techniques ensure you are dealing with a partner who will turn your ideas into reality. 




DNT  Mud filter screens

 are available with accurate hole perforation, manufactured with uniformity in flatness and straightness for high durability and easy mounting into caulking joints. 

 Hole size Centre Open area MATL. Thickness 0.50 mm 1.09 mm 19.6%* Stainless 0.30 - 0.40 mm (0.020") (0.043")   (0.012"-0.016")* 625 hpsi


Working screens / Centrifugal screens

DNT offers various types of centrifugal screens in high quality materials with precision slot and round hole perforations. The DNT Working screens are supplied with precision aligned lock-lap joints for easy installation. 



Optimal filter efficiency

Pulp press screens from DNT are manufactured with accurate hole perforations to ensure optimum filter efficiency.

DNT Pulp press screens are available in all dimensions and most materials, and the screens are supplied flattened and cut precisely to the requested dimensions.


Perforated screens according to your requirements

One of DNT's specialities is perforated screens for diffusers. The screens are produced according to your specifications and demands.

We offer perforation in stainless steel up to 10 mm thickness with various hole sizes.

We shall be pleased to make an offer according to your drawings.

 Hole size Centre Open area MATL. Thickness Consult DNT Various Various Stainless 1.00 - 15.00 mm (0.078"->0.592")


We are a leading manufacturer, supplier and exporter of Nickel Screens. Nickel screens are used in sugar and fruit juicer industry. Manufacturing is by the deposition of nickel on to an etched matrix of the shape of the required electroform. The matrix is made by the photographic reproduction of the screen surface, which is subsequently processed to confirm to screen mesh openings.


Abrasion resistant

Rust free

Deformation free

Find out more



Clients can avail from us vacuum filter screen, as we are a leading manufacturer, supplier and exporter of Vacuum Filter Screen. Vacuum filter screen is mainly used in the sugar industry and is made of stainless steel plate, sheet and strip with perforations. The filtrate treatment offered is very effective with reduced load on juice heaters. Steam consumption in drying cake is avoided in vacuum filter screen.


  • Leak proof
  • Rust proof
  • Variable speed pulley



Complete solutions

As a result of the combination of our specialized machines and our network of professional partners we are able to produce prime quality products and solutions - from the custom made perforated sheet to the fully formed and coated part.

We can cut and shape the perforated sheet to meet the needs of your final application, by shearing, water jet cutting or laser cutting.

Our punching/laser machines can combine lasercutting, punching and forming in a combined process. This offers the following competitive advantages:

  • Optimal and reliable results in laser cutting
  • Precise and constant performance in punching
  • Distinguished quality
  • Complicated shapes, special engraving and complex perforated areas
  • Levelling

For some applications a high degree of flatness of the sheet or coil is required. We offer levelling according to your requirements.  
Rolling and forming

We can roll, bend and form your perforated sheets, using special tooling where necessary, to meet your requirements. Please feel free to contact us for further information.

Depending on your specifications we are able to offer fabrications produced in our in-house welding equipment.
Other secondary operations

Above we have listed a few of the secondary operations we can provide. Please feel free to contact us for any other needs.


By close cooperation with our subcontractors we have built up a large experience within hot dip galvanizing and knowledge of how to obtain the best results.
When to use hot dip galvanised sheets

  • Generally if a lasting corrosion protection is needed.
  • For outdoor use or use in humid and corrosive environments such as swimming baths.
  • If painted/coated perforated sheets are required to be used in corrosive, humid or outdoor environments.
  • Advantages of hot dip galvanising
  • Smooth and uniform coating.
  • Sharp edges and corners are protected optimally.
  • The coating is very robust and can withstand minor bumps and bruises in connection with the mounting, transportation etc.
  • Disadvantages of hot dip galvanizing
  • Limitation of the product size.
  • Risk of distortion.Perforated sheets suitable for hot dip galvanising
  • Carbon steel cold rolled and hot rolled sheets with a minimum thickness of 1.5 mm.
  • Perforated sheets with holes that are = or > 6.0 mm in diameter (if hot dip galvanising of perforated sheets is required for sheets with holes less than 6.0 mm, e.g. R 5.0 mm or R 4.0 mm, additional investigation is required).

Sheets and fabrications are hot dip galvanised according to DS / EN ISO. Please feel free to contact us for more information


 Coated surfaces ensure an excellent protection against corrosion and an individual decorative look.

Before colour coating, perforated products must be treated appropriately to ensure the proper protection against corrosion. RMIG can arrange such processes as passivating or hot dip galvanising.
The advantages of powder coating are:

  • A thick layer can be applied in one process (50-300 micron).
  • The finished result guarantees uniform surfaces.
  • Powder coating is less affected by mechanical wear and therefore easy to clean.
  • Long outdoor life with the right preliminary treatment. 
  • Wide choice of colours.
  • Materials with holes down to and including 1.0 mm diameter can be powder coated. (If the holes are smaller than 1.0 mm further investigation is required)
  • A more cost effective process than wet coating.

    The advantages of wet coating are:
  • A very elegant appearance / finish can be achieved.
  • Wet coating is very suited for materials to appear multi-coloured.
  • Very long outdoor life if the correct layer thickness is chosen.
  • Wide choice of colours.
  • Materials with holes down to and including 1.0 mm diameter can be wet coated. (If the holes are smaller than 1.0 mm further investigation is required) 



Perforated anodised aluminium sheets are used more and more - for aesthetic, architectural or technical reasons. The untreated raw aluminium surface is very sensitive and susceptible to corrosion from atmospheric conditions. Untreated aluminium becomes dull and grey in time, whereas an anodised surface will keep its looks for many years – practically without maintenance.

When required, DNT can arrange the anodising of your perforated sheets in natural or coloured finishes.
Advantages of anodising

  • Improved corrosion resistance
  • Superb colour stability
  • Low fingerprint sensitivity
  • Scratch resistance for high value products
  • Possibility for a different decorative surface, e.g. by colouring

For indoor use we generally recommend an anodising of minimum 10 micrometres (10 mµ) on one side, and for outdoor use we generally recommend an anodising of minimum 20 micrometres (20 mµ) on one side (the side visible).  

sugar screens



  • Slots 0.04 x 2.65 mm, thickness 0.33-0.35 mm, open area 5%
  • Slots 0.06 x 2.67 mm, thickness 0.32-0.35 mm, open area 8%
  • Slots 0.09 x 2.70 mm, thickness 0.30-0.35 mm, open area 11%



Screens are available for all kind of brands used wordwide, like;

BMA, Bosco, Broadbent, Buckau Wolf, Five Cail, Hein Lehmann, Pieralisi, Salzgitter, Sangerhausen, Silver Weibull, Smith Mirless, Swidnicka Urzadzen, Techno Export, Universal, Vetek, Western States.

Other centrifugal brands available upon request.