Introduction
This document provides technical specifications and recommendations for special self-tapping screws designed for use in plastics. It includes details on recommended pilot hole diameters, technical characteristics, material and finish options, head and driving systems, and dimensions.

Recommended Pilot Hole Diameter and Plastics Material
The document specifies the pilot hole diameter for various plastics, expressed as a multiple of the screw's nominal diameter (d1). For example, for Polyethylene (PE), the recommended diameter is 0.7 x d1, while for Polycarbonate (PC), it is 0.85 x d1.

Technical Characteristics
Polyplast screws feature widely spaced threads for superior gripping and slim root diameters to prevent material cracking. They can be screwed and unscrewed in the same hole without issues. It is recommended to conduct extraction load and screwing torque tests to determine the suitable hole diameter.

Material and Finish
Polyplast screws are made from zinc-plated steel, with options for other materials like stainless steel A2 and finishes such as nickel-plated, dakromet, or phosphated.

Head and Driving Systems
The document outlines various head types and driving systems, including Panhead (TC), Countersunk Head (TF), and Hexagonal (TH). Each type has specific dimensions and tolerances.

Dimensions and Thread Tolerances
Dimensions for different screw types are provided, including nominal diameters and length tolerances. The document also mentions the possibility of manufacturing custom screws with specific thread types like HI-LO.

Conclusion
This document serves as a comprehensive guide for selecting and using Polyplast screws in plastics, providing essential specifications and recommendations to ensure optimal performance.