The ArcOne S240-12 is a fixed shade 12 auto-darkening welding filter in the 2 x 4 inch class (a horizontal lens with a 5.25 sq in viewing area). Retailer pages list a 2.5 light state, two sensors, fixed sensitivity and no grind mode or delay control. It is a simple replacement or upgrade for a helmet that takes this lens size, but a single dark shade of 12 will not suit every process and amperage.
Quick Verdict
A straightforward single-shade lens for welders who always weld at roughly the same settings and want a clear 2.5 light state. Skip it if you need adjustable shade, sensitivity or delay, or if your helmet takes a different cartridge size. Check the Amazon listing for the package details and compatibility before buying.
ArcOne S240-12 Specs
| Specification | Detail |
|---|---|
| Brand / model | ArcOne S240-12 (Amazon ASIN B0026GP7Q8) |
| Type | Auto-darkening filter, single shade, horizontal mount |
| Dark shade | 12 (fixed) |
| Light state | 2.5 |
| Sensors | 2 |
| Sensitivity | Fixed |
| Grind mode / delay | Not supported |
| Viewing area | 5.25 sq in (2 x 4 inch class lens) |
| TIG rating | 50 amps, per a retailer page |
| Standards | ANSI Z87.1 and CSA Z94.3, per a retailer page |
| Not confirmed here | Switching speed, power source, weight and warranty. Check the Amazon listing |
Specs above come from retailer product pages (Penn Tool and EMI Supply) and have not been independently tested.
Who It Is For
- Welders with a helmet that accepts a 2 x 4 inch horizontal lens.
- Users who want a simple set-and-forget lens without controls.
- Welders whose work consistently calls for a dark shade 12.
Who Should Skip It
- You switch between low-amp and high-amp work and want an adjustable shade.
- You need grind mode, delay or sensitivity controls.
- You are unsure your helmet takes this size and shape.
Is Shade 12 Right for Your Welding?
Shade needs rise with welding current, and the right number depends on the process and amperage. Check a shade chart or your helmet manual before choosing a fixed lens. If most of your work is lighter, lower-amperage welding, a lighter fixed shade or a variable lens may be more comfortable. Always test the lens on scrap and confirm it darkens fully before striking an arc.
How to Check Fit and Install
- Measure the opening in your helmet. This lens is a 2 x 4 inch class horizontal lens, so confirm the exact size and orientation in the helmet manual.
- Remove the old filter only after you see how the helmet holds the cartridge.
- Seat the new lens with the sensors unobstructed and no gaps around the edges.
- Clean the lens and cover plates with a soft, lint-free cloth. Avoid harsh cleaners.
Pros and Cons
Pros
- Simple single-shade design
- Two sensors and a 2.5 light state, per retailer pages
- Standard-size lens for helmets that accept it
Cons
- Fixed shade 12 and fixed sensitivity
- No grind mode or delay control
- Switching speed, power source and warranty must be confirmed on the Amazon listing
Is It Worth Buying?
If your helmet takes this lens and you weld at consistent settings, a fixed lens is a low-fuss option. Compare the price against adjustable cartridges before deciding. A lighter fixed alternative from the same family is covered in our ArcOne T240-10 review.
Related Guides
New to auto-darkening filters? Read how an auto-darkening welding helmet works and how to clean and maintain your helmet lens.
Frequently Asked Questions
What shade is the ArcOne S240-12?
It is a fixed shade 12 lens with a 2.5 light state, per retailer pages. The shade cannot be adjusted.
Does it have grind mode or adjustable sensitivity?
No. Retailer pages list fixed sensitivity and no grind mode or delay.
Can I use it for plasma cutting?
Do not assume so. Cutting shade needs depend on the current and process, so check a shade chart and the manufacturer guidance before using a fixed shade 12 lens for cutting.
Will it fit my helmet?
Only if your helmet accepts a 2 x 4 inch class horizontal lens. Measure your current filter or check the helmet manual first.
Final Verdict
The ArcOne S240-12 is a simple fixed shade 12 lens for compatible helmets. It suits steady, repeatable work, not mixed processes, so match the shade to your amperage and confirm fit before ordering.
