QUALITIES & PROPERTIES OF MUSCOVITE MICA

Home 9 QUALITIES & PROPERTIES OF MUSCOVITE MICA

FED SPEC HHI 536	ASTM D-351	COMMERCIAL CLASS	USES	SCALE OF COMPARATIVE VALUE
QUALITY: SUPERFINE
NMC	V-1	Clear	Geiger-Muller counter windows, Klystron Tubes, Microwave windows, X-Ray Analysis Instrument, Ultra-thin Mica Windows, Medical, Nuclear, Airborne.	100
NMS	V-2	Clear & Slightly Stained	Large transmitter capacitors, bolometers, metalized resistance cards, special high quality TV applications, air regulating diaphragms	65
QUALITY: CAPACITOR QUALITY
NMF	V-3	Fair Stained	Low power loss and high “Q” – for radio & general electronic	45
NMG	V-4	Good Stained	“Q” slightly lower – for average radio & electronic works Mica Observation Window for Gauge Glass and Oil Burner	32
QUALITY: RADIO TUBE QUALITY
NMSA	V-5	Stained A	Small capacitors and high quality radio tube spacers	14
NMSB	V-6	Stained B	Absolutely clear fuse windows for special applications	12
QUALITY: CLEAR ELECTRIC
NMH	V-7	Heavy Stained	Fuse windows, heating elements, neon electrodes, thermostat insulators, low quality tube spacers & for low voltage applications	10
QUALITY: SPOTTED ELECTRIC, STAINED ELECTRIC
NMBS	V-10	Black Stained	Resistors, motors & appliances (more surface leakage & stains conduct at high voltage)	3
NMBD	V-8	Black Dotted	110 / 220 volt insulation, transformer layer insulation, appliances	5
NMBS	V-9	Black Spotted	Non-conductive dots & spots (small surface leakage in mica)	4s

FEDERAL & ASTM Specifications

Federal and ASTM specifications may be used any time, as we are able to furnish certificate of compliance on the products fabricated.
Following are some of the applicable specifications:

ASTM-D-351-97 :	VISUAL QUALITY MICA
ASTM-D-748 :	MICA FOR FIXED CAPACITORS
HH-I-536 :	VISUAL QUALITY MICA
HH-I-538 :	ELECTRICAL PASTED MICA

MUSCOVITE MICA: PROPERTIES

Optical
Optic axial angle (2V) degrees	38 – 47
Optic plane to plane of symmetry Orientation	Perpendicular
Indices of refraction	Alfa : 1.552 – 1.570 Beta : 1.582 – 1.607 Gamma : 1.588 – 1.611
Electrical
Dielectric Constant	6.5 – 9
Dielectric Strength ( 1-3 mils thick), Volts/Mil.	6,000 – 3,000
Power Factor at 25°C (77°F) (), percent:	60 cycles : 0.08 – 0.09 1 megacycle : 0.01- 0.02
Resistivity, Ohm-Cm	1012 – 1015
Mechanical
Density	Gr./Cu. Cm. : 2.6-3.2 Lb./Cu. Ft. : 160-200
Hardness, Mohs	2.0-3.2
Cleavage	Basal, Eminent
Crystal Structure	Monoclinic
Max. Temperature with no decomposition	00-500°C
Specific heat (25°C)	.206-.209
Thermal Conductivity perpendicular to cleavage	Cal./Sq. Cm./Sec./Cm./°C : 16×10-4 B.T.U./Sq. Ft./Hr./I.°F : 4.6
Coefficient of expansion per °C perpendicular to cleavage	20° – 100° C : 15×10-6 – 25×10-6 100° – 300° C : 15×10-6 – 25×10-6 300° – 600° C : 16×10-6 – 36×10-6
Coefficient of expansion per °C parallel to cleavage	0° – 200° C : 8×10-6 – 9×10-6 200° – 500° C : 10×10-6 – 12×10-6
Tensile strength P.S.I.	37,000 – 43,000
Modulus of elasticity	25×106