Glass & Metalworkers Filters - Technical Information

This is the classic filter that has been used for many years in all types of hot glass applications, as well as kiln working, in spite of the fact that it does not filter IR radiation. The lens is dichroic (exhibits different colors under various light sources). Under incandescent light, the lens is a pronounced rose color, but changes to greenish blue under fluorescent light.

The spectral analysis of this glass at 3.2 mm thick indicates that it has good protection against ultraviolet radiation up to 360 nm, has excellent filtration at the sodium line, and excellent overall visible transmission from 400 nm to 725 nm. The glass does not offer much protection in the near or mid infrared ranges.

In general, this lens is adequate for many glass working applications where the amount of radiation generated is low.

Suggested uses are: Beginning lampworking using hot head torches and MAPP gas, or propane torches with soft glass. Acetylene torch work on silver and gold jewelry, enameling of jewelry, and any operation requiring occasional viewing of heat sources in excess of 1000°, but not for use with high pressure torches on hard materials where very high temperatures are generated.

Because this filter is an older technology, we no longer offer it in our standard and value lines. It is available only as an economy (entry level) product in non-prescription form only.

Maximum Visible Light Transmission: 89.8 %
Average (400 to 750 nm) Visible Light Transmission: 62.7 %
Average (751 to 3000 nm) IR Transmission: 66.7 %

NOTE: This lens is designed for SOFT GLASS ONLY. DO NOT USE FOR OR WITH BOROSILICATE GLASS TYPES WITHOUT ADDITIONAL FILTER PROTECTION SUCH AS OUR 7520 WELDERS CLIP-ON FLIP-UP.

This material was originally developed for enhancement of the primary colors Red, Green, and Blue. The spectral analysis of this glass filter shows it to be very efficient in eliminating the sodium flare, along with very good ultraviolet protection to 390 nm, and much improved infrared protection in the 750 nm to 1000 nm range.

A side benefit of this filter is the apparent improvement in judging the color temperature of the glass while working it. The observed color is very comfortable when viewing glowing heat sources for long periods of time.

Suggested uses are: lamp working of beads and small sculptures. Not recommended for work on very high temperature glasses for long periods of time.

AUR-92^® bifocals are supplied with Aura's exclusive "Uniform Density" feature. A 3.2 mm thick wafer of AUR-92^® is laminated over a thinly ground glass bifocal lens - giving you the same filtration through the bifocal as around it. No other manufacturer can make this claim. This lamination process also makes for a safer lens.

Lenses are available in plano (non-prescription), single vision, and laminated bifocals.

Maximum Visible Light Transmission: 79.5 %
Average (400 to 750 nm) Visible Light Transmission: 45.8 %
Average (751 to 3000 nm) IR Transmission: 59.0 %

NOTE: This lens is designed for SOFT GLASS ONLY. DO NOT USE FOR OR WITH BOROSILICATE GLASS TYPE WITHOUT ADDITIONAL FILTER PROTECTION SUCH AS OUR 7520 WELDERS CLIP-ON FLIP-UP .

This lens is a soft green color and is available in shades 1.7, 2.0, and 2.5. The spectral response of this glass shows excellent ultraviolet and infrared protection. The visible light transmission is adequate for good visibility under most shop working conditions where illumination is somewhat limited.

This filter does NOT provide sodium flare protection. Suggested uses are off hand work, allowing comfortable viewing of glory holes, fire buckets, gathering, enameling, and general kiln work.

AUR-99^® bifocals are supplied with Aura's exclusive "Uniform Density" feature. A 3.2 mm thick wafer of AUR-99^® is laminated over a thinly ground glass bifocal lens - giving you the same filtration through the bifocal as around it. No other manufacturer can make this claim. This lamination process also makes for a safer lens.

Lenses are available in plano (non-prescription), single vision, and laminated bifocals.

Maximum Visible Light Transmission: 56.2 %
Average (400 to 750 nm) Visible Light Transmission: 40.5 %
Average (751 to 2500 nm) IR Transmission: 15.2 %
ANSI Welding Shade: 1.7

Maximum Visible Light Transmission: 38.6 %
Average (400 to 750 nm) Visible Light Transmission: 25.4 %
Average (751 to 2500 nm) IR Transmission: 9.8 %
ANSI Welding Shade: 2.0

Maximum Visible Light Transmission: 23.3 %
Average (400 to 750 nm) Visible Light Transmission: 15.0 %
Average (751 to 3000 nm) IR Transmission: 3.0 %
ANSI Welding Shade: 2.5

Cobalt Blue glass is a very old glass type, and is once again available. The filter is useful in jewelry work when processing platinum, furnace port observation, and in viewing very high radiant emitters such as foundries, boilers, smelters, and carbon arc furnaces.

Under no circumstances should this lens be used in a welding application.

Users should be aware that the lens does NOT filter infrared or ultraviolet and should take necessary precautions against eye injury.

Lenses are available in flat plate only - we can edge them to fit a limited number of spectacle frames. These lenses are better suited to a visor, hood, or goggle type of frame.

Developed as a low cost alternative to the split lens AGW^®-286, this lens will knock out all competitors products. It meets or exceeds all applicable ANSI standards.

The AGW-203 filter is a "full coverage" filter, this filter is full dark, approximately a true shade 3.5 welders filter. It is available in all our Standard Line, which feature a Lifetime Warranty, and in our Value Line, which feature a One Year warranty.

20% thinner than competing filters and with similar savings in weight, this filter takes the pressure off your nose.

Maximum Visible Light Transmission: 12.4 %
Average (400 to 750 nm) Visible Light Transmission: 5.6 %
Average (751 to 3000 nm) IR Transmission: 3.4 %
ANSI Welding Shade Equivalent: 3.5 approximate

NOTE: This filter is *NOT* designed for advanced techniques such as fuming, or with intensive flare colors without additional filtration such as our 7520 welders clip on flip up.

The AGW^®-250 lens was developed to answer requests for even better ultraviolet and infrared radiation protection while also reducing the light level perceived by the eye.

It consists of a base lens of AUR^®-92 with a thin layer of either shade 4, 5 or 6 Green Welding (full coverage) cemented to the base lens. This is very desirable when working with high pressure torches and glass requiring very high temperatures.

Suggested uses are: where there is a need for attenuation of bright illumination, such as that generated when working Pyrex^®, quartz, Vicor^®, platinum jewelry work, and any operation where long periods of time are spent gazing into a high temperature furnace or fire pit.

Maximum Visible Light Transmission: 11.2 %
Average (400 to 750 nm) Visible Light Transmission: 4.9 %
Average (751 to 3000 nm) IR Transmission: 4.0 %
ANSI Welding Shade Equivalent: 3.5 approximate

Maximum Visible Light Transmission: 5.7 %
Average (400 to 750 nm) Visible Light Transmission: 2.1 %
Average (751 to 3000 nm) IR Transmission: 1.5 %
ANSI Welding Shade Equivalent: 4.5 approximate

To view the graphs for this filter, look at both the AGW®-250 filters for shade number references.

You asked, and we answered! This lens is the latest in our catalog for the best protection of infrared and ultraviolet radiation.

The lens consists of a base of our AUR^®-92 filter with a lower half lens of Green Welding (Shade 4, 5 or 6), and a upper half lens of Green Welding (shade 2, 3, or 4). You may have your lenses made half and half or one third/two thirds, standard or reversed. Your choice.

This filter is particularly valuable for use in fuming and other tasks where the brightness of the flame is a problem. It will also lend itself to most borosilicate glass work where larger sculptural work is done.

Maximum Visible Light Transmission: 11.2 %
Average (400 to 750 nm) Visible Light Transmission: 4.9 %
Average (751 to 3000 nm) IR Transmission: 4.0 %
ANSI Welding Shade Equivalent: 3.5 approximate

Maximum Visible Light Transmission: 5.7 %
Average (400 to 750 nm) Visible Light Transmission: 2.1 %
Average (751 to 3000 nm) IR Transmission: 1.5 %
ANSI Welding Shade Equivalent: 4.5 approximate

This filter is an enhanced version of the AUR^®-92. It has added infrared absorption that the AUR^®-92 does not have.

The AGW^®-300 is a revolutionary new filter designed for hot glass workers that are working at the furnace doing gathers and gazing into firepots as well as scientific and artistic glassworkers who are doing work with clear borosilicate only. The AGW^®-300 is a one-piece, non-laminated filter with the same transmission characteristics of our original AGW^®-186 laminated filter. The filter has very good visible light transmission, averaging 60 to 70%, with excellent absorption of the sodium flare.

Suggested uses are: High pressure torches and temperature applications on hard glasses like Pyrex^®, and Vicor^® where high visible acuity is required along with filtration of high amounts of infrared radiation.

Lenses are available in plano (non-prescription) and single vision prescriptions only.

Maximum Visible Light Transmission: 77.6 %
Average (400 to 750 nm) Visible Light Transmission: 60.0% %
Average (751 to 3000 nm) IR Transmission: 3 %

NOTE: This lens should not be used with colored borosilicate and/or fuming. It does not provide sufficient color flare filtration. You must use additional filtration such as our 7520 Clip-on Flip-up.

The AGW^®-325 lens was developed to answer requests for even better ultraviolet and infrared radiation protection while also reducing the light level perceived by the eye. This filter replaces the traditional AGW-286 filter.

It consists of a base lens of AGW ^®-300 with a thin layer of either shade 4 or shade 5 Green Welding (1/3 or 2/3 coverage) cemented to the base lens. This is very desirable when working with high pressure torches and glass requiring very high temperatures.

Maximum Visible Light Transmission: 11.2 %
Average (400 to 750 nm) Visible Light Transmission: 4.9 %
Average (751 to 3000 nm) IR Transmission: 4.0 %
ANSI Welding Shade Equivalent: 3.5 approximate

Maximum Visible Light Transmission: 5.7 %
Average (400 to 750 nm) Visible Light Transmission: 2.1 %
Average (751 to 3000 nm) IR Transmission: 1.5 %
ANSI Welding Shade Equivalent: 4.5 approximate