How does Astm F3561 Measure Time-based Resistance to Entry?

The ASTM F3561 standard measures time-based resistance by evaluating how long a complete glazing assembly—including the frame, glass, and security film—can deny an attacker physical access under a sustained assault. Unlike earlier standards that relied on static loads, ASTM F3561 uses a dynamic, three-phase sequence to simulate real-world attacks.

The Testing Sequence

The protocol follows a structured progression to test the assembly’s durability:

• Initial Impacts: A calibrated pendulum device delivers a specific number of strikes to weaken the glass, simulating an attacker hitting the surface with a heavy object.
• Tool Application: Immediately following the impacts, technicians apply primary tools (such as screwdrivers, pry bars, or hammers) directly to the damaged area to attempt a breach.
• Timed Resistance window: The resistance is measured in seconds. If a tool fully penetrates the assembly before the time limit for a specific level is reached, the system fails. If it denies penetration for the full duration, it passes.

Performance Levels (1–4)

Resistance is classified into levels based on the duration of the attack and the tools used:

1. Level 1: 60 seconds of resistance against a screwdriver and pry bar (5 impacts).
2. Level 2: 120 seconds of resistance, adding a hammer to the toolkit (7 impacts).
3. Level 3: 180 seconds of resistance, including use of a sledgehammer (10 impacts).
4. Level 4: 300 seconds (5 minutes) of resistance against power tools and all lower-level implements (15 impacts).

To achieve higher levels, such as Level 3, security films are typically paired with impact protection attachment systems (like wet glaze or mechanical anchoring) to prevent the entire filmed panel from being pushed out of the frame.

• ASTM F3561 Standards Explained: Forced Entry and Impact Protection