Because the filter has UV and IR coatings applied to it, eyes are protected from harmful rays regardless of active/inactive shade setting.

Best of all, the helmet stays down before, during and after the job is being done.

Auto-darkening welding helmets enable you to setup a welding joint with the hood in position.

No more head snaps to lower the helmet.

No more sloppy starts because the torch moved.

Fixed or Variable Shade

If most of your welding involves one type of material, such as steel, of the same thickness, using the same welding process, such as stick, at the same amperage, then a fixed shade #10 lens is all you'll ever need.

Standard glass lens helmets obviously are fixed shade, and the least expensive auto-darkening helmets also are available in fixed shade.

However, most people weld different materials, such as mild steel, stainless steels, and aluminum, and with different thicknesses that require the use of different welding processes, such as stick, MIG and TIG, for specific jobs. That means the welding amperage can vary from 40 amps to more than 200 amps.

With that variance comes varying degrees of brightness in the arc.

To properly protect your eyes and get the best view of the weld puddle, you need to have an adjustable or variable shade lens.

These adjustments are found either inside the helmet on the lens, or outside on the side of the helmet. Most variable shade lenses adjust from shade #9 through #12 or #13. It may be unlikely you need the shade #13 setting as seen on the suggestion chart below unless you weld at extremely high amperage or have very sensitive eyes.

Switching Speed (Lens Reaction Time)

As you shop for an auto-darkening helmet, you'll notice that most manufacturers advertise the lens switching speed.

This number tells how fast the lens will switch from its natural light state — usually shade #3 or #4 — to the darkened shade when welding begins.

The quicker a welder's eyes are shaded from the high-intensity light, the better. Too slow a reaction time will cause eye discomfort that feels like a dry scratchy sensation sometimes referred to as arc flash.

Entry-level lenses often are rated at 1/3,600 of a second switching speed. Intermediate and professional level helmets switch at speeds as high as 1/16,000 of a second or faster. Some manufactures advertise this rating in a decimal; to compare those ratings, divide 1 into 3,600 for the decimal equivalent. Generally speaking, the faster the switching speed, the more expensive the helmet and lens.

So why pay more for a faster lens? In a word: Comfort.

If you spend all day welding with a lens rated at 1/3,600, which I considered a slower reaction time, your eyes will feel fatigued by the end of the day and could have the dry, scratchy symptoms of arc flash as mentioned earlier.

With faster switching speeds, these effects are eliminated.

Solar Power and Battery Life

Some auto-darkening helmets are designed with an internal, non-replaceable battery and solar assist panel. These helmets often require a charging period in direct sunlight prior to first use, and a similar charging period if they are stored for an extended time, which can be a real bummer when you want to weld right away.

The disadvantage with this type is once the battery wears out the lens doesn't work.

A better investment is a helmet powered by a replaceable battery and solar assist panel that enables you to start welding right away.