N-Bk7 Optical Glass/Optical Glass/Borosilicate Glass

• Certification: CE, ISO, BV
• Application: Rubber, Plastic, Chemical, Construction, Metallurgy, Ceramic, Casting, Glass, Astronomy, Medicine, Biology, Communication, Milit
• Type: Optical Glass
• Shipping Cost: Estimated freight per unit.: about shipping cost and estimated delivery time.
• Currency: US$
• Return&refunds: You can apply for a refund up to 30 days after receipt of the products.
• Model NO.: RAY-OS104#
• Substrate: N-Bk7 Optical Glass
• Cte: 7.1*10-6/K (-30 Celsuis Degree to +70celsuis Degr)
• Annealing Point: 719celsuis Degrees
• Transformation Temperature Tg: 557celsuis Degrees
• Abrasion AA: Ve = 63,96 Vd = 64,17
• Transport Package: Wood Case
• Specification: 300mm*200mm*170mm
• Trademark: Raytek
• Origin: Germany
• HS Code: 2811229000
• Production Capacity: 100000kg Per Year
• Package Size: 40.00cm * 40.00cm * 25.00cm
• Package Gross Weight: 8.000kg

Product Description

General Introduction:
N-BK7 is borosilicate crown glasses with exceptional optical homogeneity. Laser components uses this glass when especially high demands of quality are put on the glass in both transmission and reflection.
BK7 is also a very pure universal optical glass. Among optical glass series products, It is one of the most standard glass types used to produce high-quality optics, mainly for the visible spectrum. The relatively hard borosilicate crown material consists of the purest raw ingredients. It contains very few inclusions and is almost free of bubbles.

Products Name: N-BK7 Glass

Main Characteristics:
1). Excellent quality at a low price.
2). Very good to process: easy to polish. The achievable polishing quality is suited for high power laser applications.
3). Material can be used without exception in transmission in the wavelength range from 400nm to 2000nm.
4). When used as HR mirror, this material can also be used outside of this wavelenght range because the beam does not penetrate the material.
BK7 is a block glass, it is not available as natural blank glass sheets. So, there are no standard thicknesses. Therefore, the glass thickness must be specified individually as per users requirements.

Thermal Properties:

Item	Value
Coefficient of Expansion:	7,1 x10^-6/K (-30 °C to +70 °C)
	8,3 x10^-6/K (+20 °C to +300 °C)
Viscosities:
Softening Point (107,6 dPa):	719 °C
Annealing Point (1013 dPa):	557 °C
Transformation temperature Tg:	557 °C
Thermal conductivity:	1,114 W/(m x K)
Specific heat capacity:	0,858 J/(g x K)(20 °C ; 100°C)

Mechanical Properties:

Item	Unit	Value
Density	g/cm^3	2.51
Yong's Module E	GPa	82 x 10^3 N/mm^2
Poisson's ratio μ		0,206
Compression strength	GPa	-
Bending strength	MPa	-
Tensile strength	MPa	-
Torsional rigidity	GPa	-
Vickers hardness	GPa	--
Knoop Hardness HK 0,1/20 (ISO9385)	-	610
Abrasion Aa*	-	ve = 63,96 vd = 64,17
Refractive index nd	-	-
Softening point	ºC	-
Annealing point	ºC	-
Strain point	ºC	-
Specific heat(26ºC)	kJ/kgK	-
Thermal conductivity ratio(26ºC)	cal/cm.sec.ºC	-
Thermal conductivity ratio(100ºC)	Cal/cm.sec.ºC	-

Refractive Index name	Wavelength (nm)	Refractive Index
ni	365,0	1.53627
nh	404,7	1,53024
ng	435,8	1,52668
nF'	480,0	1,52283
nF	486,1	1,52238
ne	546,1	1,51872
nd	587,6	1,51680
nD	589,3	1,51673
n632,8	632,8	1,51509
nC	643,8	1,51472
nc	656,3	1,51432
nr	706,5	1,51289
ns	852,1	1,50980
nt	1014,0	1,50731

Main Applying Fields:

Applying Fields:	Typical Applications 1).Demanding optical applications 2).Base material for precision optics 3).Windows, lenses, and prisms 4).Substrates for mirror and filter coatings 5).Measurement and sensor-technology use 6).Lenses and dispersion prims
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Matching Custom Manufacturing Serivce:
Including Moulding, CNC machining, Polishing, Particle beam processing, Magnetic flux conversion processing, Grinding, Coating, Lightweighting, Custom Shaping, Counterbores, Drilling & Coring, Edge & Bevel Polishing,3D Contouring, Bevels & Chamfers, Steps & Slots, Laser Cutting & Marking, Metrology & Inspection, Precision Pitch Polishing, Double-Sided Polishing, Optical Assembly, Measuring, etc.
Matching processing equipments;
1).Single side lapping and polishing machines
2).Duble sided polishing machines
3).Ring throwing machines
4).DMG five-axis five-linkage spherical milling machine
5).DMG ultrasonic machining center
6).Super large scale gantry cnc machining center (2.0*2.0m)
7).Super large scale surface grinder (1.6m*1.6m)
8).CNC cutting machines
9).Thin plate cleaning machines
10).Ultrasonic trough cleaning machines
11).Plane interferometers
12).Two dimensional detectors
13).Ion beam polishing machines
14).Magnetorheological polishing equipments

Main Export Countries & Areas: 
Usa, Uk, Japan, Germany, Spain, France, Swiss, Korea, Russia, Pakistan, India, Portugal, Canada, New Zealand, Australia, Saudi Arab, Turkey, Finland, Poland ,etc.

Raytekoptics Extra value added services offered:
1). Optical workcraft & process solution design;
2). Rough processing raw materials;
3). Semi finishing raw materials;
4). Fabricate custom sizes and shapes;
5). Design and supply custom coatings;
6). Modify and resurface customer supplied materials;
7). Drill holes, notch glass and provide beveled substrates;
8). Precision polish optics with non-standard aspect ratios;

Payment Method: by T/T or Western Union.
Delivery time: 7-10 days.
Quality Warranty: Ruitaiphotoelectric(Raytekoptics) offers quality warranty for our optics products with "3R" policy--return, replace & refund policy.
For any inferior-quality products, Ruitaiphotoelectric(Raytekoptics) is responsible for return, replacement and refund.