Perforated sheets according to DIN 24041

Perforated sheets are available in a wide variety of patterns, shapes and hole arrangements. The DIN 24041 standard makes it possible to precisely describe the type of perforation and its dimensions. Below, we explain the designations used for round, square, slotted and hexagonal holes, as well as the manufacturing process, open area and key applications of perforated sheets.

Designations according to DIN 24041

The types of sheet perforation according to DIN 24041 are:

• Lg – slotted holes, straight pattern
• Lv – slotted holes, staggered pattern
• Qg – square holes, straight pattern
• Qv – square holes, staggered pattern
• Qg – square holes, straight pattern
• Qd – square holes, 45° diagonal pattern
• Hv – hexagonal holes, staggered pattern
• Rg – round holes, straight pattern
• Rv – round holes, staggered pattern
• Rd – round holes, 45° diagonal pattern
• Deco – decorative holes

Please note that the corners of the holes may be sharp or rounded.

L – precise designation of rectangular perforation:

Lg / Lv a × b – t1 × t2

where:

a – hole width
b – hole length
t1 – distance between the centres of adjacent holes, perpendicular to the longer sides of the holes
t2 – distance between the centres of adjacent holes, perpendicular to the shorter sides of the holes

Examples: Lg 5×50-15×60; Lv 2×20-5×24

Q – precise designation of square perforation:

Qg / Qv / Qd a – t

where:

a – side length of the square
t – distance between the centres of adjacent holes

Examples: Qg 4-7; Qd 10-15

R – precise designation of round perforation:

Rg / Rv / Rd a – t

where:

a – hole diameter
t – distance between the centres of adjacent holes (in the case of Rd, this refers not to the nearest holes, but to holes in the same row)

Examples: Rg 4.5-15.0; Rd 10.0-21.0

H – precise designation of hexagonal perforation:

Hv a – t

where:

a – distance between two opposite sides of the hexagon
t – distance between the centres of adjacent holes

Example: Hv 6.00-6.70

The sheet thickness and sheet dimensions must also be specified in each case.

Manufacturing of Perforations and Sheet Appearance

Perforated sheets are produced by punching holes into sheet metal. Since punching tools and equipment are expensive, not every pattern designed on paper can be manufactured economically. For this reason, most manufacturers offer a standard range of perforation patterns, allowing designers to select the option that best meets their requirements.

The sheet thickness typically ranges from 0.5 to 3.0 mm. In the case of austenitic stainless steel, the maximum thickness is often limited to around 2.0 mm, as the material is highly ductile and more difficult to punch.

The entire surface of the sheet is not usually perforated. For both technological and practical reasons, unperforated margins are left around the edges. The quality of a perforated sheet is mainly determined by the flatness of the finished sheet and the consistency, accuracy and overall quality of the punched holes.

Applications of Perforated Sheets

Perforated sheets combine structural strength with an attractive appearance. Unlike solid panels, they create a sense of lightness and openness, which makes them suitable for a wide range of applications.

Architecture and construction – Perforated sheets are widely used for wall and ceiling cladding, particularly in railway stations, airport terminals, metro stations, hotels, sports facilities, shopping centres and similar buildings. When backlit, a perforated ceiling can create a floating effect and give the impression of additional space above it. Perforated sheets are also used for gates, fences and a variety of three-dimensional structures, as the material can be bent and rolled into different shapes.

Furniture and machinery – Perforated sheets are used to manufacture retail and warehouse furniture, shelving, frames and similar components. They are also widely used in the food industry for sieves, screening and grading equipment, drainage systems, separators, cooling equipment, trays, shelves and filters. Similar applications are found in the pharmaceutical and chemical industries.

Lighting – Perforated sheets can be used as covers, diffusers and shades for various types of lamps and lighting fixtures.

Because perforated sheets help disperse sound waves, they are also used in acoustic screens and sound-absorbing panels.

Open Area

One of the most important parameters of a perforated sheet—especially in ventilation, refrigeration and lighting applications—is its open area, designated by the symbol A₀. It is defined as the percentage of the sheet surface occupied by the holes, excluding the unperforated margins.

Open area is important when calculating the flow of gases and liquids, heat transfer and light transmission. However, increasing the open area generally reduces the mechanical strength of the sheet. Hexagonal perforation offers the highest open area, which can reach up to 80%.