Safety markings come before screen size
A welding helmet must protect the face and eyes from ultraviolet, infrared and visible arc radiation, plus sparks and spatter. Check the manufacturer's safety markings and instructions for the target market. Do not treat a good-looking shaded visor or a low price as proof of protection.
For the United States, look for clear documentation related to the applicable ANSI Z87.1 eye and face protection standard. The exact marking format and edition matter. A helmet that cannot provide its instructions or replacement parts is a poor place to save money.
Understand fixed and auto-darkening lenses
A passive fixed-shade helmet is simple and inexpensive, but the welder must lift or remove it to inspect work. An auto-darkening filter senses the arc and switches to a darker state, letting the helmet stay in place through starts, stops and inspection.
Auto-darkening is convenient for beginners, but it still needs a correct shade, a fast enough switching response and reliable power. Built-in batteries, replaceable coin cells and solar assist vary. Read the manual for the exact lens.
Match shade and settings to the process
The correct shade depends on the welding process, amperage and arc intensity. Many adjustable hobby helmets provide a shade range rather than one fixed number. Start with the manufacturer's shade guide and adjust if the arc is too bright to view comfortably.
Auto-darkening controls may include sensitivity and delay. Sensitivity helps the lens react to the arc without being triggered by ambient light; delay keeps the lens dark briefly after the arc stops, which can be useful when inspecting a hot weld. These controls do not replace a suitable protective lens.
Fit is part of protection
A helmet that slips, leaves gaps or presses uncomfortably will be moved or worn incorrectly. Adjust the headgear, check that the helmet stays in position while nodding, and make sure replacement cover lenses are available. Keep spare outer and inner lenses, especially if you grind around the welding area.
For glasses wearers, check clearance and comfort with the actual helmet. Do not modify the shell or lens system to make it fit. If the helmet cannot be adjusted safely, choose a different model.