You like to know more about glass? Investigate here all important technical terms all around the glass.


Codeletter for attack-resistant glass (DIN 52290): A = thrown projectiles resistant (A1,A2,A3);was through DIN EN 356 replaced with labelling P1A to P5A.

See below Attack-resistant glazing or Attack-resistant glass.

a - Value

Indicates, how many cubic metres of air transmit between inside and outside area per each metre of jointing length during an hour per each existing air-pressure difference of 10Pa.
(DIN 18055, Issue:1981-10 Window; air permeability of joints, water tightness and mechanical strain; requirements and testing).


Energy intake of matter


see: Etching


Gripping of two diffent materials.

Adjusted edge

see: Edge processing

Air-conditioning stones

See: Ventilation Stones.


Optical effect of toughened safety glass (ESG). The tension zones occured with toughened safety glass can lead to double break of light that could be seen observable when coloury ring appears. Anistropies are easy to recognize under polarised light or between two polarising filters. It is not unfavourable fault.

Antique glass

Kind of glass with irregular surface (contains schlieren and bubbles).

Antireflective glass

Flat glass whose coatings minimize normal Reflexes.


Abbr. from the field of sealing compounds: ethylene-propylene-terpolymer rubber (old abbreviation for EPDM - ethylene propylene diene Monomer rubber)


Inert gas, drawn on to improve k-value by multiplate insulation glass (MIG) as gas filling.

Attack-resistant glass

Laminated safety glas, with multi-layer films resp. glass composition, providing a certain resistance against a violent impact. Attack-resistant glazing, see DIN EN 356, DIN EN 1063 and DIN 52290:- thrown projectiles-resistant: code letter P1A to P5A /DIN EN 356)- smashing-resistant : code letter P6B to P7B (DIN EN 356)- gunshots-resistant : code letter BR1 bis BR7 (DIN EN 1063)- detonation-resistant: code letter D (DIN 52290 part 5; still valid at the moment)


Former codeletter for attack-resistant glass (DIN 52290): B = smashing-resistant (B1, B2, B3); was through DIN EN 356 replaced with labelling P6B, P7B and P8B.

See below Attack-resistant glazing or Attack-resistant glass.

Ball-throwing safety

In sport halls and the like facilities the ball-throw resistant elements must be applied. These must be tested according to DIN 18 032, part 3. The test specimens are thereby pelted using ball-throwing devices. Designated by certifikates.

Bank glass

Old term for attack-resistant glass in banking sector (UVV

Alte Bezeichnung für Angriffshemmende Verglasungen im Bankenbereich (UVV approval according to: C2SA/B2 , C2SF/B2)


Compound of raw materials and cullet melted in order to produce flat glass.

Bent glass

Flat glass formed by heating in bending furnace (mostly toughened safety glass).


Referred also to as "shading-coefficient". Shows the median sun-energy transmittance related to overall energy transmittance (g-value) of standard-glas window.

Blind glass

Emergence of turbid degradation, mostly on the upper coating of glass surface. Results oft from leak of MIG.

Blow pipe

Long metal tube used for blowing glass hollow bodies from melted glass (post).

Borosilicate glass

Glass with high share of boron is characterised by substantial chemic resistance, resistance to changes in temperature, however, also by low mechanical resistance.

Box-type window

Double window with inside and outside casement of single glazing. In old buildings still often to come across.

Brass glazing

Glazing with brass grill resp. with lead rods coated by brass.

Building glass casting

General term for concrete glasses, glass bricks and glass roof tiles

Building product

Building products are building materials, elements and constructions produced to permanent embedment in physical structures in order to be grounded.

Bullet-proof glass

Old term for gunshots-resistant laminated safety glass.
see: Attack-resistant glass


Special edge grinding with semicilcular profile (formerly: Round grinding).

Bull's eye

Hand-blown, round glass pane with diameter of 5 - 15 cm. Used for lead glazing (bull's eye window, bull's eye glass)


Former codeletter for attack-resistant glass (DIN 52290): C = gunshots-resistant (C1 - C5); was through DIN EN 1063 replaced with labelling BR 1 - BR7.

See below Attack-resistant glazing or Attack-resistant glass.

Cast antique glass

Patterned glass of antique-glass nature.

Cast glass

Molten and rolled glass,transparency reducing, partly with wire-netting core. See DIN 1249, part 4, Building Rules List A 11.2.

Cathedral glass

Cast glass with wrought structure.

Cellular glass

Glass foam with enclosed air (gas) cells of good insulation qualities. (DIN18 174)


To put reflective metal coating on a glass surface (production of mirrors)

Clear glass

Term for specific colourless glass. Obtained by means of special process control of the melting bath resp. by application of the purest raw materials (zero resp. minimal share of iron).

Climate load

Term for the climatic qualified pressure difference inside panes interspace of a MIG. Could be partly exceeded with several kN/m² of snow and wind loads. Climate loads are considered by dimensioning of MIG according to new "Technical Rules for the Use of Glazing with Linear Supports".


Bonding strenght of a material.

Colorescent-Glas (Opalescentglas)

Contruction is a completion of building products in order to obtain physical structures or their parts. Glass panes composed of diverse glass melts - colourless und coloured.

Coloured glass

Pigmented glasses (not only dyed surface)

Colourless glass

Glasses for optic relevant applications with reduced share of iron in order to minimize the green tint.

Complete glass doors

Frameless glass doors.

Compressive strength

Float glass features a compressive strength of 700 to 900 N/mm².


inwards coved, deepened

Condensation water

Moisture condensing e.g. from air on the cold enough building elements (thermal bridges) when humidity saturation is exceeded. Occurrence partly by heat-insulating glasses of high insulation quality during transient periods (fogging of outside panes).

Concrete glass

Compressed glass bodies (massive, hollow resp. one-side opened). Usage: walkable and drivable contructions in combination with concrete.


Contruction is a completion of building products in order to obtain physical structures or their parts.


outwards coved, elevated

Crown glass (= germ: Mondglas/Mondscheibe)

Hand-blown, round glass pane with diameter of cca. 1m.

Class of optical glasses, DIN 58 925, part 1.

Crystal glass

Term used frequently for mostly lead containing, ground hollow glass.

Crystal mirror glass

In the past: molten and rolled glass, ground on the both sides. Today: By dint of float process manufactured mirror glass.

Cut edge

Crude straight edge. (see also edge processing)


Codeletter for attack-resistant glass (DIN 52290; still valid at the moment): D = detonation-resistant; See below Attack-resistant glazing or Attack-resistant glass.


Imbued cast glass (fr.: dalle = tile), used oft as a glass doorknob.


Acoustic pressure estimated according to frequency-curve A (DIN 45 633). The curve takes into account that  intensity of a sound perceived depends on frequency (tone pitch). Also the unit for sound level dB (A). Coresponding approximately to phon-values at 1000Hz.


Old labelling (doppelte Dicke = double thickness) of industrially manufactured 3,8 mm thick window glass. Order originated from thickness: thin glass - window glass EE, MD, DD - thick glas

Dead etching

see: Etching


Ratio of weight and volume. Unit: kg/m³

Float glass features a density of 2,5 x 10³kg/m³
(wire glass cca. 2,6 x 10³kg/m³)


Process of partial crystallisation of glass. see Glass ceramics

Double-pane effect

Due to concave resp. convex bending of panes the volume of gas enclosed in composite double glazing generates a pressure equalisation with the ambient pressure. Diverse views and reflexions emerge dependig on bending. It is not unfavourable fault.

Double window

Old window structure with two frames and panes (also box-type window)

Drawn glass

Mechanically drawn window glass.


Old labelling (einfache Dicke = single thickness) of industrially manufactured 1,8 mm thick window glass. Order originated from thickness: thin glass - window glass EE, MD, DD - thick glas.

Edge (of glass)

The straight edge with glass surface form an angle of approximately 90°C

Die gerade Kante bildet mit der Glasoberfläche einen Winkel von annähernd 90° (Cut edge). See: edge processing.

Edge processing

machine-cut edge (Abbr. according to DIN 1249-12: KG)
rimmed edge (Abbr. according to DIN 1249-12: KGS) made-to-measure ground (adjusted) edge (Abbr. according to DIN 1249-12: KMG)

ground (fine-adjusted) edge (Abbr. according to DIN 1249-12: KGN)
polished edge (Abbr. according to DIN 1249-12: KPO)


The value describes ability of a particular surface to reflect heat radiation. The lower emissivity is the more heat is reflected back to the space

Enamelled glass

Toughened safety glass covered on one side by enamel colour. The coating is baked and thereby abrasion-resistant.


International term (ethylene-propylene-seal (Dicht)-material) of an organic elastomer (formerly APTK).


see: Toughened safety glass.


Abbr.: Established Technical Building-regulations (Eingeführte Technische Baubestimmung).


Attack of glass surface by dissolutions containing hydrofluoric acid. The emerging glass surfaces possess dead appearance. By extension of surfaces the sensitivity to pollution increases.


See thermal expansion coefficient

Facet, Sloped edge

Edge with angle differing from 90°C. (Abbr.: according to DIN: FK)

Filter glasses

Glasses of specific qualities as a radiation filter.


see: Surface finishing, Glass finishing.

Fire finishing

see: Fire polishing

Fire-protective glass

See fire-resisting glass resp. fire-resistance grading


Term no more valid today (originally included in the former DIN 4102, issue 1972).

Fire resistance class (for glazings)

DIN 4102

a) G fire resistance classes. Prevention of passage of fire over a specific period of time.

b) F fire resistance classes. Additional prevention of heat radiation.

c) T fire resistance classes. Door glazings; meet the requirements of the F classes. see: Fire resistance time

Fire resistance time

The assigned fire-load duration of the fire resistance classes that must to be satisfied by a material at least (30, 60, 90, 120, 180, 240 minutes).

Fire-resisting glass

Generic term for certified glasses complying with requierements of a fire resistance class.


Term no more valid today (originally included in the former DIN 4102, issue 1972). Alike: fire-resistant, highly fire-resistant


Glas Trösch's fire-protective glass.

Flame polishing

Finishing of glass surfaces ("polishing") by means of special heat treatment. Also called "Fire finishing"

Flanking transmission

Term for sound transmission through ceiling and walls adjacent to the window. Called also bypass Transmission.

Flashed glass

Bilayer glass in homogenous combination with colourless or colour undercoating and even cover-coating, likewise colourless or colour one.

Flat glass

Term for all glasses (mostly lime-natron-silica glasses or borosilicate glasses) with parallel running surfaces. Manufactured mostly by dint of float process (Floatglas).

Flexural strength

Bending stress when broken dB (Sigma).

Flint glass

Optical glasses, mostly leaded, DIN 58925, part 1.


1. By dint of float process manufactured flat glass products. The term "float"= swim acrues from the tin bath used to cool the glass melt in order to obtain as smooth surfaces as possible.

2.Current term for mirror glass though it has not found yet itself in standardisation terminology.

Fluxing agent

Additives in glass batch (soda, potass) lowering the melting Point.


See: cellular glass

Frosted glass

By means of sand blasting (sand matt) or by etching (frosted) onesided or two-sided

matted flat glass. Increased sensitivity to pollution. Matt effect of laminated safety glass is achieved through application of a matt film.

Genuine antique glass

Glass with a stronger bubbling than antique glass.


Glass is an inorganic product of fusion which is cooled to a rigid state without crystallizing. On grounds of thermodynamics glass is a super-cooled liquid.

Glass block (Glass brick)

Cuboid hollow glass component, see DIN 18175

Glass brick

Cuboid hollow glass component (DIN 18175)

Glass cement

Mostly teo-component fastener to bonding two glass elements.

Glass ceramics

Glass product of substantive resistence to changes in temperature. Manufactured by dint of specially controlled heat treatment (first exposure time at nucleation temperature, second exposure time at crystal growth temperature), when glass crystallises partly out (devitrification).

Glass edges

The Rims limiting a glass pane (glass surfaces) and flats laying between these rims (edge surfaces). DIN 1249, part 11.

Glass engraving

Local processing of surface by means of grinding Tools.

Glass etching

= Glass engraving

Glass fin

Laminated safety glass of load-bearing effect fitted for purpose of reinfocement of a constructi. Mostly related to point mounting.

Glass finishing

Subsequent processing and mechaning of glass to adapt particular usage.

Glass grinding

Erosive processing of glass surface (edge processing, flat porcessing).

Glass mortar

Mostly two-component, fast setting plastic composition for infilling vacancies between boreholings and suspension bolts in order to improve frictional connection and form-fit.

Glass prism

Old term for concrete glasses.

Glass roofing tile

Pressed light transmitting roof "brick" from glass. The form and term corresponding to standard clay bricks.

Glass types

Glasses distinguished by their chemical composition (DIN 1259)

Glass weight

see bellow "Density" or "Grammage".

Glas Trösch Design

Glass furniture;

show-cases, tables, lamps, accordion partition etc.

Glazing glass

Old term for industrially manufactured window glass. Mostly without edge processing.

Goethe glass

Hand-blown, slightly wispy glass.


A square meter of Floatglas has a weight of 2,5 kg per thickness milimeter (wire glass 2,6 kg).

Green tint

Greenisch colouring of lime-natron-silica glasses induced by a small amount of iron oxide contained in the natural raw materials. It is not unfavourable fault.

Ground edge

The whole surface of edge is threated by grinding. Grind-matte appearance - sporadic discolouration and shell defect are feasible. See also edge processing

machine-cut edge Unmaschined even edge (cut edge). (see also edge processing)


see: Total energy transmittance.

Hand-blown technique

Manufacturing of glass by dint of blow pipe. Still in use in fabrication of numerous coloured and special glasses handcraft.

Hardened glass

Out-of-date term for specific toughened safety glass (ESG). (Note: ESG features no increased hardness)

Heatable window panes

Glasses heated by means of placed or applied conductive wires or layers (heated rear window in branch of motor vehicles).

Heat-insulating glass

Glass with such coating (wenige Atomschichten dicker Metallauftrag) as it transmit radiation of particular wavelenghts (transmission) resp. reflect (reflection) the radiation (heat radiation).

Heat protection glass

see: Heat-insulating glass

Heat resistant glass

Borosilicate glass of low coefficients of expansion and a substantial resistance to changes in temperature.


Stability test of ESG over 8-hour exposure time and at median temperature of furnace of 290°C (±10 K). The test ought to induce high temperature - low temperature transformation of nickel-sulphite-inclusions which could lead to a spontaneous break. Requested among others for crash-securing glazing from ESG, ESG-facing tiles and non-quadrilateral linear bedded ESG panes.

Heat transmission coefficient

see: U-value

Hemmed edge

Cut edge with sharp rims removed. (see also edge processing)


Grinding of cut edge. The surface of edge remains crude.

see: Edge processing

High fire-resistant

Term no more valid today (originally included in the former DIN 4102, issue 1972).

High-lead crystal

see: Lead crystal

Horticultural glass

Generic term for flat glass used for horticulture purposes.

Oberbegriff für Flachglas zu Gartenbauzwecken. Horticultural blank glass DIN 11 525; Horticultural clear glass DIN 11 526.


see: Heat-Soak-Test

Hydrofluoric acid

Fluoric hydrogen acid causing substantial abrasion of glass surfaces. Used in glass etching. Severe problem for the Environment!

Ice-patterned glass

The flat glass furnished with frost patterns. Manufacturing: matted surface is covered with glue and afterwards dried. The shrinkage emerged due to hardening of glue and leads to its delamination. Through glue glass shells unhinge from the glass surface. The emerged pattern reminds a frosting formerly occured on single windows.

Infrared transmission

Uncoloured glasses possess high transmittance of light in wavelength range of 780 to 2800 nm (sloping from 780 towards 2800 nm). Absorption band of lime-natron-silica glasses occurs at 2,85 mm.

Insulation glass

see: Multi-pane insulation glass.


Spacer (comparable with u-profile) with reduced share of thermal bridges mostly from stainless steel.

Interference phenomena

Known also as Newton's rings. Interaction of more glass surfaces and light. It is not unfavourable fault.


Prismatic colours occured on the glass surface (to some extend due to partial decomposition of the surface). Can be also produced artificially through coating.

Island effect (Fracture appearance)

Formation of a glass island (breaking rim contacts nowhere the pane edge). Occurrence often by heat-strengthened glass.

Katheder's effect

Effect named after Friedrich Katheder  who researched into the interface via embedded volume of air between both panes of a MIG (multiplate insulation glass). Thereby is the applied surface load of induvidual thicknesses displayed on both single panes.

Kilopond kp.

Aside from force defined unit for force (conversion:1 kp = 9,81 N. as calculations value: 10 N)


Inert gas, drawn on to improve k-value by multiplate insulation glass (MIG) as gas filling.

Laminated glass

General term for laminated-glass systems such as a cast-resin lamination regulated contrary to laminated safety glass with no special interlayer requirements. Often used incorrectly as a notation of laminated safety glass.

Laminated safety glass

Abbr.: LSG (VSG).
Consisting of two or more float-scheets with viscoplastic interlayers laminated at the high temperature and pressure. Interlayer can contain wire or steel-fibre core. Feasible also usage of toughened safety glass or partly toughened safety glass sheets. Splinterbinding and on condition of appropriate thickness and structure attack-resistant in terms of DIN 52920. (see: Attack-resistant glass)

Lead crystal

Mostly hollow glass ware with lead-containing glass composition (at least 24% lead content, high-lead al least 30% lead Content)

Lead glass

Lead glasses (at least 5% lead content). Application: shielding from high-energetic rays (e.g. X-rays).

Lead glazing

Edging of glass using slodered lead bars. Especially in glass painting and design-glazing.

Light-chanelling glass blocks

Glass blocks with light-chanelling stamping of surface

Light diffusion

Dispersion of incident light through diffusion resp. reflection.

Light reduction

Diminished passage of light due to absoption resp. reflection.

Light transmission / Light transmittance

The light transmittance expresses the direct transmitted and visible rate of radiation in wavelength range of visible light from 380 nm to 780 nm, relating to light-sensitivity of the human eye. The light transmittance is denoted in percents and among others affected by thickness of glass. Minor oscillations are possible depending on different content of iron oxide in glass. Thus floatglas, as a single pane, features a light transmittance of 90% in wavelength range of visible light. Common uncoated insulation glass composed of two floatglas panes has a light transmittance of cca 80% and coated insulation glass cca 75 - 80 %.

Linear k-value

Thermal bridges loss coefficient Ψ (i.e.: Psi). Due to Ψ the share of thermal bridges in a window could be considered.


Antireflective glass by Glas Trösch.

Made-to-measure ground edge

The whole surface of edge is threated by grinding. Grind-matte appearance - sporadic discolouration and shell defect are feasible. (See also edge processing)

Maschine glass

Old term for mechanically drawn window glass.


Cast-glass speciality (small  squares engraved)


Cast-glass speciality (longitudinal grooves engraved )


Cast-glass speciality (small elongated rectangles engraved)


Colour balance between front tile and front windows considering the light conditions occured (with and without interior lighting)


Surface processing of glass trough etching, sand blasting or grinding.


Old labelling (mittlere Dicke = medium thickness) of industrially manufactured 2,8 mm thick window glass. Order originated from thickness: thin glass - window glass EE, MD, DD - thick glas.

MIG Abbr.:

Multiplate insulation glass.

Millefioriglas: (Thousand-flower glass)

Segments of colourful patterned bars are alloyed by dint of clear glass. Handcraft fabrication (frequent form of occurrance: paper weights), common since cca. 1000 B.C.

Mitre return

Edge forming an angle of 45°C with glass surface.

Model pane

All forms of panes deviating from square resp. rectangular


Simple homogeneous pane structure (contrary to double lamination od laminated safety glass).

Multiplate insulation glass Abbr.: MIG.

Glazing units made of two or more glass panels which are separated from each other by an interspace (pane interspace). Spacer profile keeps the distance of panels. The pane interspace is filled either with dried air or with gases resp. gas mixtures; the joints of units are airtight and moisture-proof mostly by the use of organic sealing compounds. (Prior to that, rims of glasses are welded). Air-inflated MIG: Building Rules List A 11.5.1/2 (DIN 1286-1) Air-inflated MIG with coating: Building Rules List A 11.7 (DIN 1286-1), Gas-inflated MIG with coating: Building Rules List A 11.6 (DIN 1286-2) Thickness variation og insulation glasses (panes incl. interspace): ± 1mm

Noise insulation glass (mostly insulation-glass construction)

Noise insulation (increased sound insulation) is achieved through configuration various thicknesses of glass, gas filling (SF6) in pane interspace as well as through usage of laminated safety glass or cast-resin laminated panes. Possibly also laminated safety glass with noise-insulating interlayer.


Special edge grinding with share of concave and convex Profile.


Abbr. for overhead glazing

One-way glass

see: two-way mirrors




Glasses, used in optics, with reduced share of iron in order to minimize the green tint.

Overhead glazing

Abbr.: OHG (ÜKV).
According to "Technical Rules for the Use of Glazing with Linear Supports" all the glazings with a propensity to verticals of more than 10°C. The overhead glazing regulations are also valid for vertical glazings, provided these are not only subject to short-term changeable effects such as wind action. Among them are e.g. vertical parts of northlight glazings

Patterned glass

Cast glass with embossed surface.

Picture glass

Thin flat glass for glazing of pictures (partly non-reflecting).

Photovoltaic module

Abbr.: PV-Module. Mostly silicium semiconductors (solar cells) delivering by light irradiation eletric current.  Meist Silizium Halbleiterelemente (Solarzellen) die bei Lichteinstrahlung elektrischen Strom abgeben. Degrees of efficiency: monocristalline cells: 12 to 16 % polycristalline cellen: 9 to 14 % amorphous cells: 4 to 5%

Plate resistance

A quality of building element according to DIN 52612

Polished edge

see: Edge processing


Glasses according to authorisation of Federal Communication Commission

Pressed glass

see: Glass block, Concrete glass


In the process of converting of float glass into safety glass a special inner progress of stress occurs. At first, in order to cause a modification of the glass structure (e.g. crack initiation), the acquired surface tension must be overcome. The procedure of toughened glasses manufacturing: a) thermical pretension: see: Toughened safety glass. Normally cooled glass is steadily heated to its softening temperature. Subsequent rapid cooling of the glass through cold air leads to the instant solidification of surface. The core stays viscous hence its contraction into tighter structure is enabled. As a result of different structures the surface of the glass (compact structure of a small volume) is exposed to a compression stress by the inside (open structure of large volume).

b) chemical pretension: Normally cooled glass is put in salt solution resp. molten salt of a high temperature. In the process an ion exchange takes place in surface. The effect could be enhanced through a tension spreading. Large-volume salt ions are replaced with small-volume glass ions which results in occurrance of compression stress in the surface. The progress of stress

shows stronger increase than the case of thermically toughened safety glass is.


see: Glass block, Concrete glass

Profile construction glass

Cast glass with U-profile (wider bridge, narrow flange). Ornate surface. Also with a wire core. DIN 1249, part 5. Building Rules List A 11.3


Abbr. for polyvinyl butyral.
Viscoplastic interlayer of laminated safety glass. Plain thickness of film 0,38mm. The more of the film is applied, the higher is remaining structural capacity.


Abbr. for Photovoltaic module

Quartz glass

Glass made nearly of 100% silicon dioxide (silica glass).

Raw glass

Rolled cast glass with slightly patterned surface.

Reflection-free glass

Flat glass with anti-reflective layers.

Refractory deformation temperature

Temperature range at which is softening point of glass melt placed. Also called glass transition temperature Tg. Tg of float glass moves around 520°C.

Remaining structural capacity (= Reduced safety)

Quality ensuring that no fragments fall down in case of a completely broken pane resp. that the actual function persists furthermore (e.g. crash security). Asertained via experiments.

Reverse glass painting

Handcraft to artistic paintings of glass.

Round grinding

Processing of glass edge by means of grinding in order to obtain quarter-circular arch. No more common. (today: Bullnose)


The assessed sound reduction index denotes the sound insulation ability of a building element. In the process the sound transmission through flanking contructive building elements is omitted.[dB] Other indices sound reduction:R'w; R'w,B: assessed sound reduction index incl. sound transmission through flanking building elements (embedded windows). Rw,P: assessed sound reduction index without effect of flanking building elements according to DIN 52210. In test certificates also as Rw labeled. R'w,Res: resulting sound reduction index of building elements wall incl. windows, doors, roller shutters etc.


See: Picture glass


Security alarm glass by Glas Trösch


Insulation glass by Glas Trösch with embedded shading system in pane interspace


Toughened safety glass (EGS) by Glas Trösch


Partly toughened safety glass (TVG) by Glas Trösch


Laminated safety glass (VSG) by Glas Trösch


Noise insulation glass by Glas Trösch


Screen-printed glass by Glas Trösch


Attack-resistant glass by Glas Trösch


Heat-insulating glass by Glas Trösch


Heat-insulating glass by Glas Trösch


Solar control glass by Glas Trösch


Combi-glass of heat insulation and solar control by Glas Trösch

Sandblast matting

Matting of surface by dint of sandblast.


Sulphur hexafluoride, heavy gas, resulting in increased noise insulation when applied in MIG (and also in decline of U-value).

Silica glass

Quartz glass (nearly from 100% SiO2) with extrem high resistance to changes in temperature and high UV Transmission.

Slotted corner

Sharpening of pane Corners.


Mostly a mettalic profile (stainless steel, aluminium) keeping the required distance between the sheets.

A drying agent is accomodated in the spacer as well.

Sulphur hexafluoride

Sulphur hexafluoride, heavy gas, resulting in increased noise insulation when applied in MIG (and also in decline of U-value).


Matting of surface by dint of acid-etching resp. sandblast.

Surface finishing:

Subsequent processing of flat-glass surface by means of grinding, etching, sand blasting, glue-etching and enamelling.

Tensile strength

Tensile stress at the point of rupture. e.g. (σ sigma tensile force when glass breaks).

Thermal expansion coefficient

Formula character:  α (  of float glass (at 20 to 300°C): 9 x 10  K ) denotes the fractional change in lenght per degree of temperature change. That means: a glass panel expands 0,009 mm per 1 m lenght and per 1K increase of temperature. Meassuring according to DIN 52 328

Thick (window) glass

Old term for industrially manufactured cca. 4,5 - 6,5 mm thick window glass. Order originated from thickness: thin glass - window glass EE, MD, DD - thick glas

Thin (window) glass

Old thickness regarding term for industrially manufactured cca. 0,7 - 1,6 mm thick window glass. Order originated from thickness: thin glass - window glass EE, MD, DD - thick glas

Tin side

Term for the float glass side encountering the tin bath. It is characterised by reduced mechanical solidity but then enhanced chemical resistance. Slightly fluorescent when exposed to untraviolet light.

Total energy transmittance

g-value according to DIN 67 507: indicates which fraction of incident solar radiation (wavelength range of 300nm - 2500nm) gets in the interior. This is composed of direct irradiation (tau) and heat intake through the warmed panes (q) (secondary heat supply inwards because of long-wave radiation and convective flow of heat). Values denoted in %. g = tau + q

Toughened glass

see: Toughened safety glass.

Toughened safety glass (ESG)

Thermally toughened safety glass features an increased mechanical strength as well as an increased resistance to changes in temperature. The fracture appearance is characterised by a multitude of blunt-edge crumbs of approximately  equally large. manufacturing: glass plates are heated at the refractory deformation temperature and afterwards quenched through cold air (=toughened). Therby the surface is hardenen while the inside of glass stays viskid and because of slower cooling is able to tighten stronger than the surface of glass. As a result of different structures the surface of the glass (compact structure of a small volume) is exposed to a compression stress by the inside (open structure of large volume). Mechanic stress must first overcome the acquired surface tension of ESG in order to cause modification (e.g. crack initiation) of the glass structure. The surface tension of ESG = 120 N/mm². Descriped in A 11.4 of the Building Rules List.

Transport safety

A glazing indicates transport safety only when on predictable conditions danger is impossible.


UV. short-wave range in solar Radiation.


To pull a point mounting from PVB-film out of a damaged laminated safety glass.

Uneven light refraction

See Anisotropy


New term for k-value.

Indicates heat quantity (W) passing through a building element per a square metre (m²) and at difference in temperatur of 1 K.
U = W/m² K.
Test standards of U-values for the glazing (Uv): 52619 part 2

Heat transmission coefficient according to DIN 4108.
Measuring of plate resistance: DIN 52612
Dependence of heat transmission resistance  1/i and 1/a and the thermal resistance 1/λ


The ü-mark expresses conformity of a product with Building Rules List.
ÜZ: Certificate of compliance by accredited test centre.
(MIG air-filled, without coating)
ÜH: Declaration of compliance of producer. (MIG gair-filled, with or without coating)
The ü-mark must comprise the following specifications:

1.       Name of producer

2.       Compliance certificate


brief description of authoritative technical standards and essential attributes of a building product as far as its purpose is concerned,


the label for a general technical approval as "Z" and its number,


the label for a general technical  test certificate as "P", indentification of the test centre and number of test certificates or


the label "Approval in a given case" and authorities.

3.      Pictograms or labels of certification body, if its intervention is required.

Ventilation stones

Glass blocks with vent holes.

Vertical glazings

According to "Technical Rules for the Use of Glazing with Linear Supports" all the glazings with a propensity to verticals of more than 10°C.

Warm edge

Term for MIG spacer of iproved thermical Qualities.


Special edge grinding with a profile of circle Segment.

Water glass

Water soluble glass (alkali silicate glass). Pre-product for sol-gel-process.


see bellow "Density" or "Grammage"

Welding glass

Coloured glass of peculiar filter Qualities.

White flashed opal glass

Colourless glass with a milkiness of overlay coat (external layer).

Wire glass

Cast glass with a wire-netting core. Wired glass is no safety glass!

Wire-laminated glass

Laminated safety glass with a wire core.

Wired mirror glass

Mirror glass with a wire core.

Wired patterned glass:

Cast glass with a wire-netting core and embossed surface.


Inert gas, drawn on to improve k-value by multiplate insulation glass (MIG) as gas filling.


Frameless glass shower system by Glas Trösch.