Medium Alumino-Silicate Ultra-Clear Glass

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SPECIALGLASS supplies medium alumino-silicate ultra-thin glass that raises Al₂O₃ content to boost ion-exchange capacity — delivering higher compressive stress and deeper stress depth than ordinary soda-lime glass. With ≥91.5% transmittance, a neutral ultra-clear body, and chemical strengthening to CS ≥650 MPa, it serves automotive, consumer-electronics cover glass, PV, and smart-home applications. Available from 0.25 mm to 2.0 mm, cut to your drawing.

An Ion-Exchangeable, Ultra-Clear Body

The value of this glass is in its balance, not any single figure. Holding Al₂O₃ in the 4.5–8.0% range gives the network more room to exchange ions during strengthening, so it develops higher surface compression and a deeper depth-of-layer than conventional soda-lime stock — and for cover glass, deeper exchange means a higher threshold before edge chipping and drop failure. A low-iron formulation (Fe₂O₃ <0.01%) keeps transmittance above 91.5%, so the glass holds its own in optically demanding roles like conductive glass and PV encapsulation rather than tinting the stack.

Oxide	SiO₂	Al₂O₃	Fe₂O₃	CaO	MgO	K₂O	Na₂O
Set range (%)	69.0–72.0	4.5–8.0	<0.01	6.0–8.0	3.5–5.0	0.1–1.0	13.0–14.5

Physical Properties

Consistent physical constants are what let a fabricator design tempering and lamination around the glass without surprises. The values below are held to tight tolerances across production.

Property	Unit	Value
Density	g/cm³	2.48 ±0.01
Refractive index	—	1.51 ±0.01
Young’s modulus	GPa	73.0 ±0.5
Transmittance	%	≥91.5
Volume resistivity	lg(Ω·cm)	≥10.0
Dielectric constant	—	≥7.0
Softening point	°C	750 ±10
Strain point	°C	516 ±5
Annealing point	°C	562 ±5
Thermal conductivity	W/(m·K)	0.682 ±0.10
CTE	×10⁻⁷/°C	85 ±5
Photoelastic coefficient	nm/cm/MPa	27.0 ±0.2
Poisson’s ratio	—	0.23 ±0.02
Vickers hardness	HV	610 ±10

Chemical Strengthening Profile

With chemical strengthening, the window matters as much as the peak. Preheat, strengthening, and anneal temperatures are staged so the differential between them stays within 50 °C — the margin that keeps thin glass from warping or self-shattering under thermal shock. The recommended cycle below builds CS ≥650 MPa with DOL ≥10 µm across the working thickness range, measured on strengthening salt held below 5000 ppm Na⁺ (Orihara FSM-6000LE, 590–598 nm, n = 1.51, PEC = 27.0).

Stage	Temp (°C)	Interval	Duration (min)
Preheat	380	T0–T1	60
		T1–T2	15
Strengthen	400–430	T2–T3	150–300
		T3–T4	10
Anneal	380	T4–T5	60

Strengthening results by thickness (420 °C / 3.5 h):

Thickness (mm)	0.55	0.80	1.10	1.30
CS (MPa)	≥650	≥650	≥650	≥650
DOL (µm)	≥10	≥10	≥10	≥10

Size, Thickness & Packing

Every thickness ships to a standard G5 sheet or cut to your drawing. Packing counts per box scale with thickness, so you can plan freight and line-feed against real figures rather than estimates.

Standard size: 1300 × 1100 mm (G5) — 51.2 × 43.3 in; custom shipping sizes on request
Thickness range: 0.25–2.0 mm (0.010–0.079 in)

Thickness (mm)	0.25	0.33	0.40	0.50	0.55	0.70	0.82	1.10	1.30	1.50	1.60	1.80	2.0
Pcs / box	900	1020	900	750	680	550	490	370	310	280	250	230	210

Applications

From the console of a car to the cover of a phone, this glass goes where a clear, strengthenable surface is needed in a thin format:

Consumer-electronics cover glass — phone, tablet, and notebook cover glass
Automotive displays — center-console and instrument-cluster cover glass
ITO / conductive glass and PV encapsulation — where transmittance drives yield
Smart-home & HMI — smart-speaker control panels, industrial-control touch, TFT-LCD and ultra-thin white-glass processing

Need Help?

Send dimensioned drawings (DWG/DXF/PDF) with thickness, quantity, and edge requirement, and our team will quote your glass cutting project.