California Blasters Practice Test 2026 - Free Blasters Certification Practice Questions and Study Guide

Detonating cord is designed to carry a detonation along its length, so the material in its core must detonate reliably and quickly. PETN fits that need because it has very high detonation energy and velocity and can be formed into a uniform, compact core that stays workable when wrapped in the cord’s flexible jacket. This combination ensures the detonation wave travels along the cord with speed and consistency, which is why the source lists PETN as the core load. Other materials like TNT or RDX/HMX have different performance profiles—less energy, different sensitivity, or different cost and manufacturability—making them less ideal for the cord’s core in typical practice.