D20 ET4 Protective Window 20 kW for Fiber Laser Cutting Heads (10 pcs)

replacement protective window in d20 / et4 rated up to 20 kw, made for fiber laser cutting heads. the ar coating keeps transmission high while the window absorbs contamination instead of the focus lens.

size:

• diameter (d): 20 mm
• thickness (et): 4 mm
• pack: 10 × protective window

spec:

• ar-coated for fiber laser wavelengths to reduce reflection and power loss
• suitable for 20 kw cutting systems
• 4 mm thickness gives good stiffness and flatness under assist-gas pressure
• plane-parallel faces help keep focus and gas flow consistent

material:

• quartz fused silica window
• stable under rapid local heating from spatter hits
• ar coating applied to both surfaces for high transmission

use:

• protective window in fiber laser cutting heads
• shields the focus lens from dust, fumes and metal spatter
• lets you swap a cheap window instead of cleaning or replacing the lens

compatibility:

• for fiber laser cutting heads that use round d20 mm × et4 mm protective windows
• match diameter, thickness and power class with the window you are replacing

quality:

• each window visually inspected for coating defects and scratches
• clean, chip-free edges
• packed individually to keep the optical faces clean