≡× MENU

• Interior
• Window
• Walls
• Projects
• The buildings

Self-tapping screws for sandwich panels consumption per m2. Self-tapping screws for sandwich panels. Horizontal waterproofing device

Today in Russia, sandwich panels are used almost everywhere - they are used to build shops, supermarkets, auto repair shops, car washes, industrial and residential buildings. Sandwich panels are two sheets of metal, between which insulation is laid in the form of mineral wool or expanded polystyrene. This material is fixed to the frame using specialized mounting screws. To determine which number of self-tapping screws required for fastening sandwich panels, you should know the dimensions and thickness of the elements. Let's figure out how to choose the right fasteners and calculate the required quantity.

Fastening requirements

The following requirements are put forward for self-tapping screws:

1. The fasteners must securely fasten the panel to wooden and metal surfaces without allowing it to be pulled out.
2. The self-tapping screw should not damage the surface and the insulation layer, carefully cutting a small diameter hole in it.
3. The self-tapping washer should fit snugly against the metal of the panel, ensuring tightness and protection from moisture.
4. Resistance to temperature changes, solar radiation, moisture, aggressive environments.
5. High fracture and tensile strength. During installation, calculations are made How many self-tapping screws are used to secure the sandwich panel? depending on its size, base and the requirements put forward - after fixation it should not dangle or vibrate even under heavy loads.

All our products meet these requirements - the service life of fasteners is at least 50 years. The advantages of OF screws for sandwich panels include:

1. Ease of cutting through metal due to the unique drill bit at the end of the fastener.
2. Possibility of fixing on any material.
3. Ease of tightening due to the presence of an enlarged hex head.
4. Aesthetic appearance fasteners
5. Reliable fixation of the sheet due to the presence of the main thread and the thread at the screw head.

To calculate consumption of self-tapping screws for fastening sandwich panels, We recommend contacting designers - it is not recommended to select the number yourself. Contact us – we will advise you and answer your questions.

Self-tapping screw design for sandwich panels

Classic fasteners consist of:

1. Grounds. The base is a solid metal rod attached to the head. Near the head there is a thread for fastening, then there is a smooth part, the main thread of a special design, and at the end there is a drill made of high-quality hardened steel, which cuts through metal with ease.
2. Tip. It is attached to the base and is a metal washer with a turnkey head. Behind the metal washer there is an EPDM gasket that protects the hole from moisture and cold.

How to choose the right one

To pick up self-tapping screws for 1 sandwich panel, you should understand how thick the slab will be and what you plan to attach it to. The box must be dense and durable, ideally metal, so that the self-tapping screw does not break out of it during operation. The length of the fastener varies from 85 to 285 mm (for panels from 50 to 315 mm). To calculate the length, add the thickness of the metal frame and another 15 mm to the thickness of the sandwich panel. That is, if you attach a 200 mm thick panel to a 7 mm frame, then 200+7+15=222 (rounded to big side up to 225 mm). The diameter of the fastener usually varies from 5.5 to 6.3 mm - this is enough to cut a hole in metal up to 16 mm thick.

Installation rules

Before proceeding with installation, you should calculate consumption of self-tapping screws for sandwich panels per 1 m2. Typically, a coefficient of 1.5 is used for wall panels, and 2 for roofing panels. This means that 1.5 and 2 screws are required per 1 m2 of surface, respectively. There is no need to try to save on fasteners - their cost is relatively low, while they are responsible for the strength and reliability of the entire structure. Saving on self-tapping screws leads to damage to the panels, their falling out and significant reconstruction costs. Remember that the plane must withstand powerful mechanical and wind loads.

Installation of self-tapping screws is usually carried out at a distance of 300 mm from the edge of the block - this is necessary to ensure that the panel does not bend or break. The fasteners are located at a distance of 800-1200 mm from each other, depending on the expected loads and the area in which the structure will be used.

Let's consider how many screws do you need for one sandwich panel? classic size on the run:

1. For a panel with a length of more than 6 meters - at least 8 fasteners.
2. There are 6 fasteners per panel with a length of 4 to 6 meters.
3. For a panel with a length of up to 4 meters – 4 fastenings

To install panels on a metal frame, no preliminary drilling is required - the self-tapping screw cuts through the metal itself and securely fixes the panel. For concrete surfaces Usually, the panel and the hole for the dowel are first drilled, and then a self-tapping screw is driven into it.

Note that the above is the simplest calculation number of screws for sandwich panels, excluding damaged and lost items. To calculate everything as accurately as possible, contact our managers - they will advise you and help you with the selection!

Sandwich panels are often used in the construction of structures of varying complexity. Thanks to them, the construction process can be accelerated, and the energy efficiency of the building also increases, since such panels already contain insulation.

For installation you need to prepare special fasteners. Among them are self-tapping screws for sandwich panels.

Properties of self-tapping screws and requirements for them

Special fastening panel elements have the following properties:

• they are able to reliably fix materials regardless of the time of year;
• the plate can be successfully fixed to any material;
• Since they are practically invisible on the structure, its aesthetic appearance is guaranteed after installation.

You should also know that self-tapping screws intended for similar designs must meet the following requirements:

• ensure reliable connection between the panel and different materials;
• during installation, the surface of the product should not deteriorate under the influence of self-tapping screws;
• tightness must be ensured at fastening points;
• fasteners must be resistant to seasonal changes in material.

Composition of fasteners

Self-tapping screws for sandwich panels consist of the following elements:

• grounds;
• tip;
• heads with six sides.

Externally, the base is divided into three parts. Immediately behind the head there is a thread, and then there is a smooth part, at the base there is again a thread. During the installation of structures, the smooth middle of the fastener goes into the panel itself.

The fastening element also comes with a washer equipped with a rubber gasket. It is needed to protect the hole from liquid penetration, making the mount sealed.

Types and sizes of fasteners

You need to choose one or another self-tapping screw depending on the thickness of the structure:

• the length of the fastener must be greater than that expected to fit into the box;
• The material used to make the self-tapping screw must be able to maintain its strength and integrity when screwed in for as long as possible.

You cannot skimp on fasteners for sandwich panels. Cheap fakes may lose the integrity of the thread during installation.

When choosing self-tapping screws, the coating is of no small importance. The fasteners themselves are made primarily from carbon steel, the coverage looks like this:

When installing sandwich panels, you should choose the right fasteners. The length of the screw should be 85-285 mm. Be sure to take into account the thickness of the metal profiles and panels themselves. If the mount has a diameter ranging from 5.5 to 6.3 mm, then the metal frame should have a cross-section from 1.5 to 15 mm, respectively. The panels themselves should have a thickness of 17 to 240 mm.

The length of the fastening element is calculated by summing the thickness of the panel, metal profile, thickness of the gasket (it is 5 mm) and the length of the drill.

GOST standard

When installing sandwich panels, builders often use self-tapping screws equipped with a countersunk head and a pointed end; they comply with the GOST standard 11652–80. Such products are convenient and durable in terms of use and they are highly effective.

According to the existing standard, this fastener equipped with a pointed end and has a strength class B. The thread can have a diameter ranging from 2.5 to 8 mm. The standard also allows for the production of self-tapping screws not only based on metal, but also on plastic.

Rules for installing sandwich panels

Before you begin the installation process, you should calculate their number for future work. For this purpose, it is necessary to take into account the placement of panels and their sizes. Do not skimp on fasteners by trying to make the step wider, since in this case you need to provide the material with maximum strength, taking into account atmospheric and mechanical loads.

Fastening must be done at a distance of at least 30 mm from the edge. Use two self-tapping screws with a pitch of 900-1200 mm for each of the columns. Depending on this value, as well as taking into account all probable loads and will be calculated average consumption self-tapping screws:

• if the panel has a length of 6 m or more, then to attach it you need to prepare about 8 screws;
• if it is shorter than 6 m, then 6 fastening elements will be needed;
• and only 4 fasteners will be needed to mount a panel up to 4 meters long.

Structural installation process will differ depending on what material was used to produce the frame:

If knots are formed during the connection of adjacent sections, they can be sealed using special sealing foam or mineral wool. The span of structures affects the size of the joints. If it is less than 4 meters, then the seam will be about 15 mm. If the span is longer, the indicator will increase to 20 mm or more.

Manufacturers of self-tapping screws

The cost of installing sandwich panels using special self-tapping screws depends on whether you will do it yourself or use the help of hired specialists. Doing it yourself will cost much less, but remember that it is better not to undertake it if you do not have the proper experience.

As already mentioned, there is no need to save on purchasing self-tapping screws. You should not buy suspiciously cheap fasteners, they can quickly break.

• "Harpoon".
• SFS intec.
• "Scorpion".

During the construction of industrial, warehouse, agricultural buildings and structures, public and commercial buildings, as well as refrigerators.

System composition

1. Load-bearing structure (metal or reinforced concrete frame), according to the project
2. Sealing tape - 3.0 mm
3. Sandwich panel with thermal insulation TECHNOSANDWICH S
   1. Profiled galvanized steel with polymer coating– 0.5-0.7 mm
   2. Adhesive for sandwich panels – less than 0.5 mm
   3. Thermal insulation TECHNOSANDWICH S – thickness according to calculation No. 1*
   4. Adhesive for sandwich panels – less than 0.5 mm. *
   5. Profiled galvanized steel with polymer coating* – 0.5-0.7 mm.
4. Panel fastening
5. Cover plate made of galvanized steel, thickness 0.5-0.7 mm

Main stages and principles of installation

1. Base structure

The base of the system can be a metal or reinforced concrete frame of the building, as well as a free-standing half-timbered row of posts.

2. Horizontal waterproofing device

In the support zone facade panels on the bases it is necessary to make anti-capillary horizontal waterproofing with TECHNOELAST EPP material

3. Installation of the first row of facade panels.

To fix the first row along the bottom panel, a locking angle is installed at the base.

The first row of panels is suspended at a distance of 1-3 cm from the base. The gap between the panel and the base is filled non-flammable thermal insulation TECHNOLITE. All panels are connected to the frame through sealing tapes. The panels are fixed with anchors to the supporting frame. The vertical joint of the panels must have a gap, which is also filled with TECHNOLITE material.

4. Installation of facade panels.

The bottom edge of the panel rests firmly on the bottom installed panel and snaps into the lock. This joint must first be sealed with butyl rubber cord. The panels are fixed with anchors to the supporting frame. All panels are connected to the frame through sealing tapes. The vertical joint of the panels must have a gap, which is filled with TECHNOLITE material.

From the outside, the vertical joints of the panels are closed with shaped profiles.

5. Installation of sealing tape.

The tape is glued to a surface that has been cleaned of dirt and protective films. The location of the tapes must provide a 100% guarantee of preventing air from entering the façade thermal insulation.

6. Installation of facing screen

The following materials can be used as facing screen:

• porcelain stoneware slabs;
• fiber cement boards;
• aluminum composite panels
• metal or PVC siding.

To create a complex façade geometry that does not replicate the surface of sandwich panels, a ventilated façade substructure is used. In the case of finishing sandwich panels, a “hat profile” is used to fasten the cladding, fixed in the required direction to the sandwich panel.

1. Required Tools and accessories for installing sandwich panels:

1.1. Soft slings with a lifting capacity of 5 tons, 10 m long - 2 pcs.

1.2. Rubberized lower spacers and upper spacers with stops, size 1200x150 mm - 4 pcs. (Fig. 1). Protruding parts of fasteners are not allowed on the rubber surface to avoid damage.

1.3. Nylon cable with a diameter of at least 4 mm, for stabilizing bundles and individual panels during lifting (Fig. 2).

1.4. Spacer frame or traverse - to prevent soft slings from coming together when lifting a bundle longer than 7 m. -1 pc.

1.5. Special clamps for transfer to the installation site - 2 pcs. (Fig. 3).

1.6. Soft slings with a lifting capacity of 1 ton. - for hanging clamps: - 2 pcs.

1.7. Scaffolding or mechanized platforms for lifting people to the required height (according to the height of the ridge of the building) - 2 pcs.
1.8. Electric tool for cutting thin sheet metal that does not cause heating of the metal (electric jigsaw) and manual scissors - 1 pc.

1.9. Electric drilling machines with special nozzles for driving screws (it is recommended to use a specialized tool with adjustable tightening force and a device for gripping screws) - 2 pcs.
1.10. Measuring tapes (length 7.5-10 m) - 2 pcs.
1.11. Markers for metal and polyethylene - 4 pcs.
1.12. Construction level (0.6-1 m) - 1 pc.
1.13. Construction plumb.
1.14. Set of non-metallic gaskets (plastic, paronite, polyethylene) 80 -100 x 40 - 60 mm, thickness 1-1.5 mm (thickness should be the same): - 10 pcs.
1.15. Core - 2 pcs.

2. Preliminary work when installing sandwich panels

2.1. Draw up a site layout plan. Take into account the type, brands, ease of transferring them to the place with minimal rearrangements of the crane and scaffolding.
2.2. Level the storage areas for panels (uneven surfaces are not allowed; fill with crushed stone if necessary).

3. Preparatory work

3.1. Level the area adjacent to the modular building with a width of at least 2.5 m for installing scaffolding or moving mechanical lifting platforms.
3.2. Level the area inside modular building for installing scaffolding or moving a mechanical lifting platform.
3.3. Complete all work on the installation of the building frame, especially welding work and frame coloring.
3.4. Carry out final leveling, placing bottom marks on all columns.
3.5. Mark the top and bottom marks on window, gate crossbars and the top under the roof, taking into account the installation size -1000 mm, the gap between - 1.5 mm and the lock - 22 mm in order to prevent errors.
3.6. Unpack the boxes (if boxed).
3.7. Carry out an inspection, avoiding dragging on the surface of another panel.
3.8. Place packs of panels by brand and in quantities required for a given element of the facade and roof. Placement should be carried out on prepared sites, taking into account the free movement of the crane, etc. Vehicle.
3.9. Install scaffolding or mechanized platforms for lifting installers to the panel fastening site.

4. Preparation for installation of sandwich panels

4.1. Remove the packaging film from the pack.
4.2. Place the panel on polystyrene, wood, and foam pads (Fig. 5). You can do it right on the same pack.
4.3. Carefully inspect the lock parts; protrusion of mineral wool beyond the inner shelf of the lock is not allowed. If necessary, remove excess mineral wool with a wooden scraper.
4.4. Delete protective film from lock connection
4.5. Remove the protective film from the areas adjacent to load-bearing structures(columns, crossbars)
4.6. Remove the protective film from the locations of the fastening elements - self-tapping screws.

5. Installation of sandwich panels

Installation must begin with the walls.

Before this, install the mask of the plinth cover - point 9.1 .

5.1. Attach the clamps at a distance of 1/4-1/5 L from both ends. The center of the pressure plate should be located no closer than 150 mm from the edge (Figure 5). 5.2. Tie nylon cables to the edges for stabilization when moving to the fastening point.
5.3. Holding it, lift it with a crane (Fig. 5).
5.4. Deliver the sandwich panels to the installation site.
5.5. Align the marks on the column (crossbar) according to points 3.4. and 3.5. with edges (Figure 7).

5.6. Installation gap between the ends, between the panels and the roof, the base, adjacent walls, etc. should be 20-30 mm (Fig. 6).
5.7. The gap in the lock connection of 1-1.5 mm must be set using spacers inserted along the edges into the lock during installation (Fig. 6). It is prohibited to apply excessive pressure during joining; there must be a guaranteed gap to avoid bulging metal sheet in a locking connection.
5.8. Check building level horizontal (vertical) edge.

5.9. Mark the drilling site.
5.10. Secure with self-tapping screws to the supporting structures (Fig. 8), maintaining the distances according to Fig. 9. An increase in the joint and between the screws and the joint is unacceptable - because shaped elements are designed specifically for these dimensions, and if the distance increases, the screw head will interfere with the normal installation of the shaped elements.
5.11. Remove spacers.
5.12. The number of fastening screws on the main surface of the wall should be selected at the rate of 1 screw per 1 square meter
5.13. The number of fastening screws at the corners of the wall should be selected at the rate of 4 - 5 screws per purlin or column, due to increased wind separation at the corners of the building.
5.14. The screws are tightened until the bending of the metal washer is eliminated. Bending into the washer means excessive tightening - which is unacceptable.

6. Sequence of installation of sandwich panels

6.1. The first one is installed on the base at a distance of 20-30 mm from the base. It is mandatory to check horizontality (verticality).
6.2. The second one is installed on the first one with a gap of 1-1.5 mm through spacers.
6.3. The third and subsequent ones are similar.

(6.4. Panels connecting to a window, door, gate require increased attention due to the connection with the crossbars and neighboring ones (Fig. 10). They sometimes require cutting out a part for the opening.

ATTENTION!Cutting is done at the installation site of the sandwich panels electric jigsaw after marking. When marking, it is necessary to take into account the installation gaps of 20-30 mm between the panels and window or door blocks. After checking the horizontalness of the cutting lines with a building level on both sides, a cut is made on both sides, the mineral wool is cut through and the piece is removed.

If cutting is impossible on the mounted panel (protruding parts of the crossbar, close proximity of structures, etc.), markings are applied with inside directly at the installation site of the sandwich panels, without fastening with self-tapping screws. Then it is removed and placed on special stands. The markup is transferred to outer side. Cutting is done on both sides, according to the markings, with a jigsaw, after which the cotton wool is cut through sharp knife and the piece with mineral wool is removed. Lift with a cutout to the installation site with extreme caution, because the product has lost its original bearing capacity!
6.6. The latter, when laid horizontally, is connected to the roof overhang. The joint can be either on the inner sheet or on the top profiled sheet. It is necessary to check the gaps between the wall and roofing panel. The gap should be 20-30 mm.
If necessary, trim or trim the inner sheet with a recess of mineral wool (Fig. 11).
6.7. If the integrity is damaged, attachment to the crossbar is not carried out.
If trimming was done, then attachment to the longitudinal substructure is mandatory.

After installing the sandwich panels on a given site, or on the entire building, they proceed to installing roofing panels.

7. Sequence of installation of the roofing part of the sandwich panels

7.1. The correctness of all the others depends on the installation of the first roofing part.
7.2. Needs to be examined carefully. Remove the roof overhang from the cutting area mineral wool, including corrugated ones. Carefully inspect the lock parts; protrusion of mineral wool beyond the inner shelf of the lock is not allowed. If necessary, remove excess mineral wool with a wooden scraper.
7.3. The first is mounted in an open wave towards the end of the building. ATTENTION: do not confuse left and right overhang trimming!
7.4. Attach the clamps at a distance of 1/4-1/5 L from both ends. The center of the pressure plate should be located between the first and second or second and third corrugations.
7.5. Tie nylon cables for stabilization during transfer to the execution point.
7.6. While holding, lift the panels with a crane.
7.7. Deliver the sandwich to the installation site.
7.8. Align the edge with the end of the building, along the outer edge.
7.9. Set the overhang to the distance specified in the project.
7.10. Check the parallelism of the end edge with the axis of the building by pulling the cord along the ridge, and if there is no joint, then along the facade of the building. This determines what edge the mounted panels will have: smooth or stepped.
7.11. The gap in the locking connection is 1-1.5 mm. It is prohibited to apply excessive pressure during joining; there must be a guaranteed gap to avoid bulging of the locking connection.
7.12. Mark the drilling site.
7.13. Secure with self-tapping screws to the supporting structures.
7.14. The number of fastening screws on the main surface should be selected at the rate of 1 per 1 square meter, and with a distance between runs of 2 m, 2 per run.
7.15. The number of fastening screws at the corners of the roof should be selected at the rate of 4 screws per run, due to increased wind separation at the corners of the building.
7.16. The number of fastening screws on the sides of the roof should be selected at the rate of 3 screws per run.
7.17. The screws are tightened until the bending of the metal washer is eliminated. Bending the washer inward means over-tightening, which is unacceptable.
7.18. Docking is carried out according to Fig. 12.

8. Sequence of installation of sandwich panels

8.1. The installation sequence is according to Fig. 13.

9. Installation of window and door units.

9.1. Fastening of window and door units is carried out only to metal substructures; fastening is prohibited.
9.2. Installation clearances of 20 mm are required.

10. Sequence of installation of strips.

Before installing the flashings, fill all installation gaps with TERMO LIGHT PM-35 mineral wool.

The minimum overlap of the flashings is 40 mm, the maximum pitch of the fastening screws is 400 mm. Washers with rubber gaskets must be installed on the screws to ensure tightness. On the sides of the flashings facing upwards, it is necessary to apply a layer of sealant 10-15 mm wide inside.

10.1. The mask of the plinth cover is installed first. It must be installed before installing the sandwich panels first. wall panel sandwich. The edge of the mask should go into the mineral wool. The distance from the outer edge to the outer edge of the mask must be carried out strictly according to the design, observing this value throughout the entire length of the facade. The mask is fastened to the base using dowel-nails 6 x 40 mm.
10.2. After installing the base cover mask, the wall covers are installed.
10.3. Base cover. Apply sealant to the upper inner side. The lower flange is inserted behind the mask of the base flashing, it is pressed against the wall and secured with self-tapping screws to the upper part.
10.4. Roof overhang flashing mask. Check that the installation gap is thoroughly filled and sealed. Bend the cut trapezoids to cover the corrugations top sheet. Attach only to the wall with self-tapping screws.
10.5. Attach the roof overhang flashing only to the wall.
10.6. Attach corner strips starting from the bottom. Make a trim on the lower flashing to ensure a tight fit to the base flashing (Fig. 14). Make trimming on the top flashing to ensure a tight fit of the overhang to the flashing.

10.7. Façade extension strips. Make a trim on the lower flashing to ensure a tight fit to the base flashing. Make trimming on the top one to ensure a tight fit to the overhang strip.
10.8. Roof end frame flashing. Make a trim on the lower flashing to ensure a tight fit to the corner flashing and prevent water from flowing in.
10.9. Ridge strip, along with two ridge strip masks. Bend the cut trapezoids to bridge the gap between the corrugations of the top sheet. Check that the installation gap is thoroughly filled and sealed.
10.10. Flashings for windows, doors, gates, starting from the bottom flashing. Trim the flashings for a tight fit. Apply sealant on the inside with a width of 10-15 mm. on all edges of the flashings facing upward to prevent water penetration.
10.11. Perform sealing polyurethane foam from inside the premises of those installation gaps that were not sufficiently sealed from the outside of the building.
10.12. Install the internal plinth strips.
10.13. Internal overhang flashings.
10.14. Internal corner strips.
10.15. Internal ridge caps.
10.16. Internal flashings of the roof end.
10.17. Internal flashings for windows, doors, gates.

11. Work after completion of installation of sandwich panels

11.1. When completing the installation of the panels, it is necessary to remove the protective film both outside and inside the building. 11.2. Remove the protective film both outside and inside the building. 11.3. Remove the protective film on the strips both outside and inside the building. 11.4. Wash off traces of dirt with a damp cloth. If this method is ineffective, use a rag soaked in solvents - white spirit, 646 or acetone. No more than 40 reciprocating movements at a time; if traces of dirt are not removed, repeat after 30-40 minutes.

In the construction of houses, various cladding materials are often used for insulation and protection. concrete walls from adverse weather conditions. To secure the sandwich panels to the façade of the building, a special metal frame is installed. The facing material is attached to this metal profile using special screws. They differ from other types of fasteners due to their unique two-part thread. Self-tapping screws for sandwich panels are available with different sizes. They are selected depending on the thickness of the facing material and the metal frame.

As mentioned above, self-tapping screws for finishing a building have two threads (at the end of the fastener, small and frequent, and near the head, larger and rarer). They are separated by a smooth gap. This fastener structure is necessary for more reliable installation of sandwich panels. A large-diameter thread located near the head of the self-tapping screw secures facing material, and the lower fine thread cuts into the metal structure.

The space between the two threads prevents the cladding panels from wobbling by keeping them level. These self-tapping screws (hardware) are additionally supplied with steel washers and vulcanizing gaskets that do not allow moisture to pass through to the facade of the building and to the fasteners themselves. The hardware head has a hexagonal shape for screwing with a wrench.

In production we also have self-tapping screws for sandwich panels, which are attached to concrete or wooden wall without the use of an additional frame. They only have one solid thread.

Screw sizes

To select the correct fastener size, it is necessary to take into account the thickness of the metal profile and facing material.
Metal carcass, which can be used for self-tapping screws with a diameter of 5.5/6.3, has a cross-section from 1.5 mm to 15 mm.
Fasteners are available in different lengths from 75 to 280 mm.
The thickness of sandwich panels varies from 17 to 245 m.
Calculation required length The self-tapping screw can be made using the formula: panel thickness + metal profile thickness + drill length + 5mm (gasket thickness). The relationship between the length of the fastener and the thickness of the material can also be seen in special tables.

Roofing screws

In roofing, fasteners also play an important role. Their service life will depend on their quality finishing materials. Roofing screws are divided into three types:

1. For metal. They have a drill end that allows you to punch holes up to 1.2 mm. When pre-drilled, the self-tapping screw can penetrate up to 6 mm. Such fasteners are made of steel and coated with a layer of zinc.
2. On wood. They have a sharper end for better penetration into the wood. If a long-length self-tapping screw (from 40 cm) is used for installation, then the hole for it is pre-drilled with a drill of a smaller diameter.
3. For corrugated sheets. These fasteners are similar to self-tapping screws for sandwich panels. They can be used for installing corrugated sheets on both metal and wooden bases.

Harpoon self-tapping screws

Among the many brands of self-tapping screws, we can highlight “Harpoon” fasteners, which are available in several models. All of them are made of carbon steel, and differ in their anti-corrosion coating and size.

Self-tapping screws with a diameter of 5.5/6.3 mm are produced with Ruspert and Xylan coatings. They can have a length from 85 to 285 mm. Such fasteners are intended for metal profiles with a thickness from 4 to 12.5 mm. The cross-sectional size of the panels should not exceed 225 mm.

For thinner metal structures(from 2 to 5 mm) “Harpoon” fasteners are produced with the same diameter but shorter length (from 85 to 230 mm). Self-tapping screws for sandwich panels are coated with anti-corrosion solution “Ruspert” or “Xylan”. They can be used for mounting panels with thicknesses from 25 to 210 mm. There is also a series "HARPOON PLUS", designed for thick metal structures. Such self-tapping screws are used for profiles with a thickness of 4 - 16 mm and 4 - 25 mm. They differ in thread diameters (4-16 mm require 5.5/6.3 mm, and 4-25 mm require 6.3/7.0 mm).

Video about HARPOON Plus self-tapping screws for sandwich panels HSP25-R-S19