2. Class 4 (Open Style): Flexibility at a Lower Cost
A Class 4 laser (like the HeatSign HS-FL20) has an exposed laser source. The beam travels through the air to the part without a physical barrier.
✅ The Pros:
Unlimited Part Size: Since there is no box, you can mark a 2-meter long pipe, a car chassis, or a large mold. You are not limited by the door size.
Portability: Many Class 4 machines are handheld. You can take the laser to the part (e.g., marking a VIN on a truck frame).
Cost: You aren’t paying for the sheet metal, safety glass, and interlock sensors.
❌ The Cons:
Mandatory PPE: Everyone in the “Nominal Hazard Zone” (NHZ) MUST wear laser safety goggles rated for the specific wavelength (1064nm for fiber).
liability Risk: If an employee takes off their glasses “just for a second,” you are liable for eye injuries.
Fume Extraction: Without an enclosure, smoke spreads into the room. You need a targeted fume extractor nozzle close to the source.