Sandwich Panel Self-Drilling Fasteners

Product detail · Updated 10 October 2026

Product and application brief

Sandwich-panel self-drilling fasteners are selected for the complete panel-to-support connection, not simply by screw length. Metal skins, the intervening core, the receiving support and any sealing or load-spreading components are separate inputs. A generic roofing screw name does not establish a suitable panel fastening system.

Product forms and reference names

Choice or field	What to identify
High-thread and free-spin catalogue construction	EJOT JT3-D-12H describes a steel-support sandwich-element fastener with high thread, an under-head free-spin zone and a pre-assembled sealing washer. These features are selected-product choices, not universal features of all panel screws.
Timber-support construction	EJOT JT3-D-2H-6.5/7.0 is separately identified for panels onto timber. A steel-support drilling range must not be substituted for the timber embedment and joint requirements.
No-top-thread hidden-fixing example	SFS SX5-6.3 describes concealed panel fixing using spreader plates and a screw without top thread. This is distinct from a high-thread arrangement: specify the panel joint and plate, rather than assuming either fastener fits every panel.
Primary fastening versus secondary attachments	Panel-to-support fastening, sheet overlaps and accessory attachment are different connections. This detail concerns the primary panel connection; provide the actual joint drawing if the enquiry concerns another interface.

Panel stack and receiving support

State outer and inner skin materials and thicknesses, core material, overall panel thickness and profile or concealed-joint geometry. Identify the receiving steel or timber separately. Total panel thickness is not the thickness of metal the drill point cuts, and it is not automatically the fastener clamping range.

Thread arrangement and panel face

Select the documented high-thread, free-spin or no-top-thread construction with the panel system. SFS distinguishes its no-top-thread fastener for seating through spreader plates, while EJOT lists high thread and an under-head free-spin zone on a different series. Do not infer panel-face support, controlled compression or suitability from a generic long-screw illustration.

Clamping range, length and drilling point

Use the chosen manufacturer's measurement diagram to distinguish nominal length, clamping range, skin/support stack and point projection. The SFS CLmet description explicitly accounts for the application build-up rather than just nominal panel thickness. Steel drilling and timber embedment are different checks. No universal range, embedment or tightening value is supplied here.

Sealing washer and hidden-fixing components

Specify whether a washer is supplied, its metallic backing and seal designation, and any spreader plate required by the panel joint. Verify the exact selected variant: a family-level washer description does not prove every order code includes that assembly. Washer diameter or seal material alone does not establish a weather-tight connection.

Material construction and assembly evidence

Body material, drill-point construction, finish and service environment need independent specification. EJOT's documented stainless-body/hardened-steel-point example is not an all-stainless identity or FastenerBridge approval. Third-party certifications, installation tools and performance values belong to their exact products and conditions; request the selected documentation and panel-system review.

Specification fields

Choice or field	What to identify
Identity and joint	Controlled panel-system/joint drawing, selected fastener reference and revision; exposed or concealed fixing, primary panel or secondary attachment.
Panel skins and core	Each skin's material/thickness, core type, overall thickness, profile, joint shape and surface finish.
Receiving support	Steel material/thickness or timber requirements; gaps and intermediate layers, stated separately.
Head and thread layout	Head/drive, high top thread or no top thread, free-spin zone and corresponding seat/plate from the selected drawing.
Length and fastening range	Nominal length and datum, documented clamping range, required point clearance and steel engagement or timber embedment review.
Drill point	Selected point designation and documented metal stack/drilling capability; do not use panel depth as drilling thickness.
Seal and plates	Included or separate washer, backing/seal specification and variant code; spreader plate and mating-panel requirements if specified.
Material and installation	Body/point construction, finish, environment, selected setting instructions, assembly qualification and required reports; no generic torque or capacity.
Quotation inputs	Pieces, destination, packing/traceability and exact drawings or part lists. Availability, supply scope and timing require confirmation.

Common product questions

Is any long roofing screw a sandwich-panel fastener?

No. Identify the panel joint, skins/core, support, selected thread layout, clamping range and sealing or spreader assembly.

Does every sandwich-panel screw have top thread?

No. Original catalogues distinguish high-thread arrangements from a no-top-thread concealed-fixing example. Follow the specified panel system and selected fastener drawing.

Is panel thickness the drilling capacity?

No. Overall panel depth includes the core. The drill point and receiving support must be checked against the documented metal stack or timber application separately.

Product references

References checked 10 October 2026 identify structures, not FastenerBridge stock, certification or brand affiliation. Final requirements follow the selected specification. No universal dimensions, load rating or tightening torque is stated.