EN ISO 15481:1999

Overview

EN ISO 15481:1999 (published by CEN as an adoption of ISO 15481:1999) defines the characteristics and designation of cross recessed pan head drilling screws with tapping screw thread. The standard covers screws with thread sizes ST2,9 up to and including ST6,3, specifying geometry, dimensional limits and how these screws interface with sheet or plate materials. It is intended for manufacturers, designers and quality professionals working with self‑drilling/tapping fasteners for thin materials.

Key topics and requirements

• Scope and thread sizes: The standard applies to cross recessed pan head drilling screws with tapping screw threads in sizes ST2.9 to ST6.3.
• Head and recess types: Defines pan head geometry and cross‑recess forms (Type H and Type Z) and provides dimensions for recess depth and penetration.
• Dimensional data: Tabulates key dimensions (head height, thread major diameters, effective thread length lg, nominal length l, radii r, and drilling point function references) so manufacturers can ensure interchangeability.
• Drilling range: Specifies the sheet/plate thickness ranges for which each thread size is intended (drilling capability increases with thread size - up to about 6 mm for the largest sizes).
• Functional and mechanical properties: References ISO 10666 for mechanical and functional property requirements (drilling point function and performance).
• Thread and tolerancing: Relies on ISO 1478 for tapping screw thread form and ISO 4759‑1 for tolerances (product grades and dimensional tolerances).
• Finish and acceptance: Surface finish guidance references ISO 4042 (electroplated coatings) and ISO 3269 acceptance inspection procedures.

Practical applications

• Fastening sheet metal, thin plates and components where a self‑drilling, self‑tapping solution is needed.
• Typical use cases include appliance assembly, HVAC and ductwork, electrical enclosures, light‑gauge steel framing and general sheet‑metal fabrication.
• Useful where a pan‑head, cross‑recess drive is preferred for assembly speed, torque control and a flush bearing surface.

Who should use this standard

• Fastener manufacturers designing and certifying drilling/tapping screws.
• Product designers and mechanical engineers specifying fasteners for sheet‑metal assemblies.
• Quality assurance and procurement teams ensuring conformity and interchangeability.
• Installers and OEMs seeking standardized fastener dimensions and performance expectations.

Related standards

• ISO 10666 - Drilling screws with tapping screw thread (mechanical/functional properties)
• ISO 1478 - Tapping screw thread
• ISO 4757 - Cross recesses for screws
• ISO 4759‑1 - Tolerances for fasteners
• ISO 4042 - Electroplated coatings for fasteners
• ISO 3269 - Acceptance inspection for fasteners

Example designation (from the standard):
Drilling screw ISO 15481 - ST3,5 3 16 - Z

Keywords: ISO 15481, EN ISO 15481, cross recessed pan head drilling screws, tapping screw thread, drilling screws, fasteners, sheet metal screws, ST2.9–ST6.3.