Welding Glass Explained: Shade Numbers, Clear Cover Lenses and When to Replace Them

Every welding helmet and shield needs a dark lens to protect the welder’s eyes — but that lens is a spare part, not a permanent fixture, and the shade number stamped on it isn’t arbitrary.

In short: our welding glass spares come in a dark shade (DIN 11) for the actual welding filter, and clear for the cover lens that sits in front of it and takes the spatter damage. Both come in two sizes — 108x50mm and 108x80mm — matched to which helmet or shield they’re replacing. The clear cover lens is the one that needs replacing most often; the dark filter lens underneath it lasts much longer if the cover is doing its job.

Dark shade glass: the actual welding filter

Our Welding Glass Dark DIN 11 108mm x 80mm (309-SDWG) and 108mm x 50mm (309-SDWGN) are the dark filter glass that blocks arc radiation — DIN 11 shade, matched to the lens opening size of our standard flip-front and handheld welding shields.

Clear glass: the cover lens that protects the dark filter

Our Welding Glass Clear 108mm x 80mm (309-SCWG) and 108mm x 50mm (309-SCWGN) sit in front of the dark filter, taking the spatter and scratches that would otherwise damage the actual protective lens. It’s a genuinely sacrificial part — cheap, easy to swap, and designed to be replaced more often than the dark glass behind it.

Matching size to your helmet or shield

Both dark and clear glass come in 108x50mm (matching our standard welding helmet, 308-2) and 108x80mm (matching the flip-front helmet, 308-1300, and the handheld shield’s own 110x50mm opening is a close but distinct size — check the actual lens frame before ordering). Getting the size wrong means a lens that doesn’t seat properly in the frame.

When to replace the clear cover lens

Once the clear cover lens has visible pitting, scratching or spatter buildup that affects visibility through it, it’s due for replacement — that’s the entire point of having a sacrificial layer rather than exposing the DIN 11 filter directly to spatter. The dark filter glass itself only needs replacing if it’s cracked, chipped, or the shade has visibly degraded.

Frequently asked questions

What’s the difference between the dark and clear welding glass?

The dark glass (DIN 11) is the actual protective filter that blocks arc radiation. The clear glass sits in front of it as a sacrificial cover lens that takes spatter and scratch damage.

How often should the clear cover lens be replaced?

Whenever it shows visible pitting, scratching or spatter buildup that affects visibility — replacing the cheap clear lens regularly is what protects the more expensive dark filter behind it.

What sizes does the welding glass come in?

108mm x 50mm and 108mm x 80mm, matched to the lens opening size of the helmet or shield being fitted.

What shade is the dark welding glass?

DIN 11, a fixed shade suited to standard arc welding work with our fixed-shade helmets and shields.

See our guides to welding helmet types and welding shields and goggles to check which lens size your equipment needs, and our guide to leather welding hoods and welding curtains to round out the series.

Browse our full welding glass range in stock now, or get in touch if you’re not sure which size fits your helmet.