Toolcraft expansion pins made of spring steel according to DIN 1481 standard, designed for heavy-duty applications in bicycle headsets. These expansion pins, with dimensions of 18 mm in diameter and 140 mm in length, provide secure fastening for bicycle headset components, including bearings and associated parts. The spring steel construction ensures high tensile strength and durability under bicycle conditions, delivering reliable performance in regular use. The heavy-duty design offers increased load capacity compared to standard variants and is suitable for various outdoor recreational bicycle applications. Each pack contains 10 expansion pins for multiple installations or replacements. Precision manufacturing ensures consistent dimensions and reliable expansion properties during assembly in bicycle headsets. These expansion pins serve as essential components for maintaining proper headset function and steering precision in bicycle equipment. The spring steel material provides corrosion resistance and retains mechanical properties across typical outdoor temperature ranges during cycling activities. Professional installation ensures secure fastening of headset bearings and associated components, contributing to overall bicycle safety and performance. The standardized dimensions allow compatibility with various bicycle headset systems that require 18 mm diameter expansion pins.