PS3 Self-Drilling Screw for Sandwich Panels

Dedicated self-drilling screw for fastening insulated sandwich panels to steel and aluminum roof profiles — dual-diameter 6.3 / 5.5 mm geometry for higher pull-out, sealed with an EPDM washer, drilling and tapping in a single action.

Self-drilling — no pre-drillSandwich panels & roofsDual-diameter 6.3 / 5.5 mmSteel & aluminum up to 6 mmEPDM sealing washerLengths 60–230 mm

The Adit self-drilling screw family

Choose the right self-drilling screw for your profile thickness, environment and sealing requirements.

PS3Self-drilling · Sandwich panels · 6.3/5.5 mm PSLLong point · Panels to beams up to 12 mm ABEI304 stainless · Coastal & aggressive environments BIE / BIE A4Bi-metal · Drills stainless & hard steel AUTO / BAUTOExtra-long drill point · Steel up to 12 mm ABP / ABRAesthetic heads · Countersunk / round

What is the ADIT PS3 self-drilling screw?

The PS3 self-drilling screw (Self-Drilling Screw for Sandwich Panels) is a dedicated self-drilling screw for fastening insulated panels (sandwich panels) to steel and aluminum profiles on roofs. The screw drills and taps in a single continuous action — with no need for pre-punching or pre-drilling — while creating a tight, sealed and durable connection.

What makes the PS3 unique is its two-stage screw-body geometry: the screw is built from two threaded zones with different diameters. At the start of the body (P1) the diameter is 6.3 mm (ST6.3), and further along the body (P2) the diameter narrows to 5.5 mm (ST5.5). This unique structure gives the screw exceptional pull-out, grip and sealing performance.

When do you use the PS3 screw? The screw is intended for fastening sandwich panels on roofs directly to a metal profile (steel or aluminum), in thicknesses of up to 6 mm. It comes with an EPDM washer for full sealing and enables fast, code-compliant work.

The advantages of the PS3 screw — not every sandwich-panel screw is the same

Unique dual-diameter geometry: 6.3 mm diameter at the start (P1) and 5.5 mm further along (P2) — a structure that increases the pull-out load and prevents the screw from loosening over time.
Approved technical data: precise pull-out and shear values for every steel and aluminum profile thickness (enabling safe, code-compliant engineering design).
Direct-fastening technology for the panel: the screw drills and taps in a single action — no pre-punching, no accessories and no “dead time” on site.
Proven field durability: made of C1035 steel with a cold-galvanized coating (Atlantis C4 for long lengths) — it does not break, bend or disappoint under harsh roof conditions.
Dedicated EPDM washer: every screw length can be ordered with an EPDM washer for perfect sealing; the 195 and 230 mm lengths come with a washer as standard.
Engineering support and warranty: ADIT engineers are available to help select the model, calculate loads and ensure compliance with strict building codes. Tel: 054-7976110.

The dual-diameter geometry of the PS3 — what sets the screw apart

Unlike a standard self-drilling screw with a single diameter along its entire body, the PS3 is built with two separate, complementary threads:

Zone	Diameter	Pitch	Role
Drill point	—	7.5–9 mm long	Drills up to 6 mm profile thickness
P1 — leading thread (drill-point side)	⌀ 6.3 mm (ST6.3)	1.8 mm	Drills and passes through the steel/aluminum profile; creates strong initial grip in the supporting profile
P2 — screw body (head side)	⌀ 5.5 mm (ST5.5)	1.8 mm	Enters the sandwich panel; the diameter difference creates a “clamping” effect that pulls the panel toward the profile and raises the pull-out load

Why does this matter? The dual-diameter structure ensures the panel is “trapped” between the two threads and cannot loosen. Pull-out loads are significantly higher than a single-diameter screw, and the connection remains stable even under wind and seismic loads.

Approved technical data — connection to a steel profile

The following data forms the basis for safe structural design with the PS3 screw. All values in the tables are in kN per single screw, ST5.5 diameter (screw body P2). Please note: the values listed below are characteristic failure loads (Nrk/Vrk). An appropriate safety factor must be applied for engineering design. The designer must also verify the profile’s own bearing capacity against tear-out.

PS3 ST5.5 — connection to a steel profile

Load parameter (kN)	Steel thickness 2 mm	Steel thickness 3.5 mm	Steel thickness 5 mm
Characteristic failure load — pull-out (Nrk)	5.4	8.7	9.6
Characteristic failure load — shear (Vrk)	4.8	4.8	4.8
Design load — pull-out (Nrd)	2.5	4.0	4.8
Design load — shear (Vrd)	3.7	3.7	3.7
Recommended load — pull-out (Nrec)	1.8	2.9	3.4
Service load — shear (Vrec)	2.6	2.6	2.6

PS3 ST5.5 — connection to an aluminum profile

Load parameter (kN)	Aluminum thickness 2 mm	Aluminum thickness 4 mm	Aluminum thickness 5 mm
Characteristic failure load — pull-out (Nrk)	2.0	7.6	9.6
Characteristic failure load — shear (Vrk)	4.8	4.8	4.8
Design load — pull-out (Nrd)	0.9	3.5	4.8
Design load — shear (Vrd)	3.7	3.7	3.7
Recommended load — pull-out (Nrec)	0.7	2.5	3.4
Service load — shear (Vrec)	2.6	2.6	2.6

Note: the shear capacity does not account for tear-out of the profile (steel or aluminum). The designer must check the profile’s tear-out capacity to determine the final shear capacity. Using steel screws for a connection in aluminum can cause galvanic corrosion.

Geometry and dimensions — PS3 screw

The ADIT PS3 screw comes with uniform, precise dimensions across all lengths in the series:

Parameter	Value / range	Unit
Screw diameter (P2 — body)	5.5	mm (ST5.5)
Outer diameter incl. thread (P1 — head)	6.3	mm (ST6.3)
Head diameter (dk)	10.5	mm
Washer diameter (C)	5.46	mm
Head thickness (K)	4.1–4.5	mm
Hex socket (e)	8	mm
Thread pitch P1 (6.3 mm)	1.8	mm
Thread pitch P2 (5.5 mm)	1.8	mm
Drill-point length	7.5–9	mm
Maximum steel thickness for drilling	up to 6	mm
Available lengths	60–230	mm

Quick installation guide — PS3 screw for sandwich panels

Mark the entry point: A light tap with a punch (center punch) for precise centering will prevent the screw’s drill point from slipping at the start of rotation — especially important on smooth panel materials.
Prepare the right screw gun: Drilling speed in steel: 1,000–1,800 rpm. Drilling speed in stainless steel: 600–1,000 rpm. Maximum installation torque: 10.4 Nm. An impact driver may be used — but stop immediately once the screw head seats against the panel.
Drive perpendicular to the profile: Hold the screw gun at 90 degrees to the material with steady, continuous pressure. Driving at an angle breaks the drill point, weakens the connection and impairs the sealing.
Stop when the screw seats and the washer is compressed: When the screw seats and reaches the required clamping torque — stop. You must ensure the EPDM washer is compressed evenly but not fully crushed — this is the key to a hermetic seal against rain.

Part numbers and lengths — PS3 screw

Part no.	Anchor type	Length (mm)	Small box (units)	Coating
PS55060	PS3 5.5/6.3×60	60	500	Cold galvanized
PS55082	PS3 5.5/6.3×82	82	500	Cold galvanized
PS55098	PS3 5.5/6.3×98	98	500	Cold galvanized
PS55115	PS3 5.5/6.3×115	115	500	Cold galvanized
PS55130	PS3 5.5/6.3×130	130	250	Cold galvanized
PS55150	PS3 5.5/6.3×150	150	200	Cold galvanized
PS55180	PS3 5.5/6.3×180	180	200	Cold galvanized
PS1955195	PS3 5.5/6.3×195	195	200	Atlantis C4
PS1955230	PS3 5.5/6.3×230	230	200	Atlantis C4

Any screw can be supplied with an EPDM washer on request. The 195 and 230 mm lengths come with an EPDM washer as standard.

All sandwich-panel screw models in the ADIT catalog

PS3: Self-drilling screw for sandwich panels on roofs, dual-diameter geometry 6.3/5.5 mm, hex head with washer. The dedicated series for fastening panels to straps and roof profiles.
PSL: An extra-long screw for fastening sandwich panels to beams, with a long drill point (Long Point) enabling drilling up to 12 mm profile thickness. Also available with an EPDM washer (PSL+ARVUL).
ABEI: Self-drilling screw made of 304SS stainless steel. Suitable for aggressive environments, outdoors, coastal areas and the chemical industry.
BIE / BIE A4: Bi-metal screw (stainless-steel body, hardened-steel drill point). Designed for fast, direct drilling in stainless steel and hard steel (also available in A4/316SS).
AUTO / BAUTO: Self-drilling screw with an extra-long drill point — enables drilling up to 12 mm steel thickness. The BAUTO is the bi-metal stainless-steel version.
ABP / ABR: Screws with aesthetic heads. ABP — conical countersunk head for smooth surfaces. ABR — round, flat head.
RSZ / RS A2: Self-drilling screw with a small lens head for fine seams and frames.

Engineering consulting + a quality PS3 screw = a complete solution for sandwich-panel roofs

The market is flooded with sandwich-panel screws from obscure sources that usually break under load, drill slowly, rust quickly — or worse, fail to provide a real seal. What sets ADIT Ltd. apart from other suppliers is its engineering knowledge and technical documentation. The company’s engineers are available to help calculate and select the correct screw length according to panel thickness, determine screw spacing according to wind and snow loads, and ensure compliance with building codes. This saves the cost of field failures and enables code-compliant, approved structural design.

Frequently asked questions — PS3 screw for sandwich panels

What makes the PS3’s dual-diameter geometry unique, and why is it important?

The PS3 screw is built with two threads of different diameters: P1 at 6.3 mm diameter at the drill-point end — drilling and passing through the supporting profile — and P2 at 5.5 mm diameter on the screw body located inside the panel. The difference between the two diameters creates an “active clamping” effect: the panel is trapped and drawn between the two threads and cannot loosen. The result — higher pull-out loads than a uniform-diameter screw, and excellent durability under wind and vibration loads.

What is the difference between the PS3 and the PSL, and when do you use each?

PS3 is intended for fastening sandwich panels to straps/purlins — relatively thin profiles up to 6 mm thick, with a standard drill point (point No. 3). PSL is intended for fastening panels to beams — thicker profiles up to 12 mm, thanks to a long drill point (point No. 5) that enables deeper penetration. Both come in the 6.3/5.5 mm dual-diameter geometry.

How do you choose the correct PS3 screw length according to panel thickness?

Length calculation: sandwich-panel thickness + supporting-profile thickness + minimum P1 thread engagement in the profile (at least 10 mm). For example, an 80 mm panel on a 3 mm profile — you need a screw of at least 93 mm, i.e. choose the PS55098 (98 mm). The manufacturer’s technical data table specifies the suitable panel thickness for each part-number code.

What is an EPDM washer, and why is it critical for the PS3 screw?

When you drive a PS3 into a sandwich-panel roof, the screw creates a hole in the metal skin that could let rain and water into the insulation layer. PS3 models with an EPDM washer (which comes as standard on the 195 and 230 mm lengths, and to order on all other lengths) include an EPDM rubber sealing disc — highly resistant to UV rays, heat and cold. With proper tightening, the rubber is compressed and forms a perfect, hermetic seal against water ingress around the hole.

Can the PS3 be used to fasten a sandwich panel to an aluminum profile?

Yes, the PS3 is approved for connections in aluminum, but there are two important things to know: first, pull-out loads in aluminum are lower than in steel (especially in thin thicknesses) — you must work according to the dedicated aluminum load table. Second, steel screws in a connection to aluminum in an exposed outdoor environment can cause galvanic corrosion. Consider using stainless-steel screws (ABEI) in particularly aggressive environments.

What is the difference between Nrd (design load) and Nrk (characteristic failure load) — and which one do you use for design?

The characteristic failure load (Nrk) is the value determined in destructive laboratory tests — the value at which the screw or profile collapses. You must not design a project based on the failure load! Engineers divide the failure load by an appropriate safety factor (per international standards) to arrive at the design load (Nrd) — which is the safe value for design. For conservative design, you can use the recommended load (Nrec). ADIT provides all three values in its technical tables.

Why does my screw’s drill point break or fail to drill?

In most cases this happens due to: driving at an angle (not 90 degrees to the material), using a screw-gun speed higher than 1,800 rpm or lower than 1,000 rpm, trying to drill a profile thicker than 6 mm with a PS3 (which is rated up to 6 mm only), or uneven pressure at the start of drilling. For thicker profiles, switch to the PSL with a long drill point, or to the AUTO series.

What is the PS3’s galvanized coating, and which environments is it suitable for?

Lengths up to 180 mm come with a cold-galvanized coating, and the 195 and 230 mm lengths come with an Atlantis C4 coating — a more advanced coating that is more durable in harsh outdoor conditions. Cold galvanizing is suitable for indoor environments and protected enclosures. For aggressive outdoor environments, coastal areas, or where ETA documentation is required — consider using stainless-steel screws.

Can a PS3 screw be removed and re-driven into the same hole?

The screw can be removed, but it is strongly not recommended to reuse the same screw in the same hole. The double thread (6.3 + 5.5 mm) damages both the screw thread and the hole, and re-driving will significantly impair the pull-out capacity. If re-installation is needed, replace with a new screw and, if possible, position it at a new point.

What is the recommended screw spacing for PS3 screws on a panel roof?

Screw spacing depends on the wind and snow loads in the area, the panel type and the roof geometry. There is no single “standard spacing” — the designer must calculate the spacing according to the relevant service loads and the screw loads from the tables. ADIT engineers are available to help with this calculation. Contact us at Tel: 054-7976110.

Planning a sandwich-panel roof? Tell us the panel thickness, profile type and load — our engineers will help you select the right PS3 length and screw spacing.

Talk to our engineers