ATTRIBUTE	ACCEPTANCE LIMITS
THICKNESS	+/- 0.02mm. Total difference in thickness in a direction perpendicular to rolling direction should not exceed 0.02mm.
LENGTH	Upto 700mm + 0.0/ - 0.5mm
	701 to 2000mm + 0.0 / -1.0mm
	Over 2000 mm + 0.0 / - 1.5 mm
WIDTH	Upto 150 mm +/- 0.1 mm
	151 to 500 mm +/- 0.2 mm
	501 mm and above +/- 0.3 mm
CAMBER	1.0 mm max. on 2000mm length
V NOTCH	90 deg +/- 5 minutes
MITRED ANGLE	45 deg +/- 5 minutes
HOLE DIAMETER	+ 0.10 / - 00mm
STACKING FACTOR	95.0% min. for 0.23mm thick material
	96% min. for 0.27mm and 0.30mm thick material
	97% min. for 0.35mm thick material
INSULATION RESISTANCE	Min. 10 Ohms/cm2 as per Franklin method described in IS 649-1996
BURR	25 microns maximum
WEIGHT OF EACH STEP	+ 0.5% to 1.0% or as per customer's requirements.
WATT LOSS	M3 Grade: Max .77 watts/kg at 1.5T and 50Hz
	M4 Grade: Max 0.89 watts/kg at 1.5T and 50Hz
	M5 Grade : Max 0.97 watts/kg at 1.5T and 50 Hz.
	M6 Grade: Max 1.1 watts/kg at 1.5T and 50 Hz
	Watt loss is also specified as below.
	A	B	C
	A Denotes metal thickness (100 times actual thickness of material; in mm)
	B Denotes alphabetal code. In IS 3024. It is CG for conventional grade and HP for high permeability grade.
	C Denotes guaranteed watt loss (number denotes 100 times the watt loss at flux density of 1.7 Tesla and a frequency of 50Hz)
	Example : 27CG 130 means that thickness is 0.27mm, that it is conventional grade CRGO and it has a maximum watt loss of 1.30 watts/kg at 1.7T and 50Hz.

ATTRIBUTES	ACCEPTABLE LIMITS
OUTSIDE DIAMETER	OVER	UPTO	TOLERANCE IN MM
	40 100 300	100 300 -	+/- 1.0 +/- 1.30 +/- 2.0
INSIDE DIAMETER	- 0.0MM/+1MM
WIDTH/HEIGHT	UPTO 200MM OD : '-0.0/ + 1 MM OVER 200 MM OD : '-0.0/+1.5 MM
SLIT BURR	25 microns
WEIGHT	-0.0 /+0.2 % of nominal weight
MAGNETIC CHARACTERISTICS	Grade M3 0.29AT/CM at 1.5T/50Hz M4 0.31 AT/CM at 1.5T/50Hz M5 0.35 AT/CM at 1.5T/50Hz M6 0.40 AT/CM at 1.5T/50Hz
	NOTE: (a) For high Permeability Grades (HiB grades) the magnetizing force is guaranteed in terms of AT/cm at 1.7T/50Hz depending on grades. (b) Magnetizing force is specified at 1.5T only, but we can test at 2 or more flux densities depending on customer's requirements.

Given below are major international standards for CRGO materials which so far has been the main guide-line for lamination and transformer manufacturers.

MAJOR INTERNATIONAL STANDARDS
GRAIN-ORIENTED ELECTRICAL STEEL STRIP

JAPANESE
JIS C 2553 (1986)
Classification		Density (kg/dm3)	Iron Loss (w/kg) W 17/50	Magnetic Flux density (T) B8
Synbol	Thickness mm
27 P 100	0.27 0.30 0.35	7.65	1.00 max.	1.85 min.
27 P 110			1.10 max
27 G 120			1.20 max.	1.78 min.
27 G 130			1.30 max.
27 G 140			1.40 max.	1.75 min.
30 P 110 30 P 120			1.10 max. 1.20 max.	1.85 min.
30 G 130			1.30 max.	1.78 mm.
30 G 140			1.40 max.
30 G 150			1.50 max.	1.75 min.
35 P 125			1.25 max.	1.85 min.
35 P 135			1.35 max.
35 G 145			1.45 max.	1.78 min.
35 G 155			1.55 max.
35 G 165			1.65 max.	1.75 min.

U.S.A
AISI (1983)
MAXIMUM CORE LOSSES* ELCTRICAL STEELS GRAIN ORIENTED FULL PROCESSED ASTM A665
ASTM Type	Former AISIType	Thickness		Maximum Core Loss at 15 kg (1.5 T) ™*™
				W/lb		W/kg
		Inch	mm	60 Hz	50 Hz	60 Hz	50 Hz
27G053 30G058 35G066	M-4 M-5 M-6	0.0106 0.0118 0.0138	0.27 0.30 0.35	0.53 0.58 0.66	0.40 0.44 0.50	1.17 1.28 1.46	0.89 0.97 1.11

MAXIMUM CORE LOSSES* ELCTRICAL STEELS GRAIN ORIENTED FULLY PROCESSED ASTM A725
ASTM Type	Former AISI Type	Thickness		Maximum Core Loss at 17 kg (1.7 T)
		Inch	mm	W/lb 60 Hz	W/kg 50 Hz
27H076 30H083 35H094	M-4 M-5 M-6	0.0106 0.0118 0.0138	0.27 0.30 0.35	0.76 0.83 0.94	1.27 1.39 1.57

GERMAN
DIN 46400 : Blatt 3 (1983)
Magnetic and technological properties of oriented magnetic steel sheet and strip
Grade		Nominal thickness mm	Specific total loss 1) W/Kg max		Magnetic Flux density2) t min. B8
Code Number	Material Number		P 1,5	P 1,7
VM 89-27	1.0865	0.27	0.89	1.40	1.75
VM 97-30	1.0861	0.30	0.97	1.50	1.75
VM 111-35	1.0856	0.35	1.11	1.65	1.75

BRITISH
BS 601: Part 2 (1973)
Maximum specific total loss at a peak magnetic flux density of 1.5T and a frequency of 50 Hz.
Grade	Maximum specific total loss W/kg
35M7 35M6 30M6 30M5 28M5 28M4	1.23 1.11 1.07 0.97 0.95 0.89

However for the last couple of years the emphasis has been shifted from the guaranteed wattloss/Kg at 1.5 T/50 Hz to 1.7 T / 50 HZ as can be seen in IS.3024 - 2006 Chart given Below.

Table 1 Magnetic Properties of Conventional Grain Oriented (CGO)
Electrical Sheet Tested at 1.7 Tesla and 50 Hz.

Grade (1)	Nominal Thickness mm (2)	Maximum specific Core Loss (W/kg) At 1.7 Tand 50 Hz (3)	Minimum Polarization in Testla at a Field strength of 800A/m (4)	Minimum Stacking Factor (5)
23CG110	0.23	1.10	1.78	0.945
23CG120	0.23	1.20	1.78	0.945
23CG127	0.23	1.27	1.75	0.945
27CG120	0.27	1.20	1.78	0.950
27CG130	0.27	1.30	1.78	0.950
27CG140	0.27	1.40	1.75	0.950
30CG130	0.30	1.30	1.78	0.955
30CG140	0.30	1.40	1.78	0.955
30CG150	0.30	1.50	1.75	0.955
35CG145	0.35	1.45	1.78	0.960
35CG155	0.35	1.55	1.78	0.960
35CG165	0.35	1.65	1.75	0.960

NOTE : The above samples are sheared longitudinal to the rolling direction and then stress relief annealed in a neutral or reducing atmosphere to develop magnetic property at 780° C to 820° C.


Table 2 Magnetic Properties of High Permeability Grain Oriented (HPGO)
Electrical Sheet Tested at 1.7 Tesla and 50 Hz.

Grade (1)	Nominal Thickness mm (2)	Maximum specific Core Loss (W/kg) at1.7 T and 50Hz (3)	Minimum Polarization In Testla at a Field strength of 800A/m (4)	Minimum Stacking Factor (5)
23HP90	0.23	0.90	1.85	0.945
23HP95	0.23	0.95	1.85	0.945
23HP100	0.23	1.00	1.85	0.945
23HP100	0.27	1.00	1.85	0.950
23HP110	0.27	1.10	1.85	0.950
23HP110	0.30	1.10	1.86	0.955
23HP120	0.30	1.20	1.85	0.955
23HP125	0.35	1.25	1.85	0.960
23HP135	0.35	1.35	1.85	0.960

NOTE : The above samples are sheared longitudinal to the rolling direction and then stress relief annealed in a neutral or reducing atmosphere to develop magnetic property at 780° C to 820° C.

CRNO STANDARDS

Given below are IS-648 CRNO standards

SI No.	Designation	Nominal Thickness mm	Max Core Loss at 50 Hz (W/kg)		a.c. Magnetisation 50 (Hz) mln. Value of B Max Tesla			Anisotropy of total specific loss at 1.5 T (%max)	No. Of Bends (mln) assumed density Kg/dm*
			1.0 T	1.5 T	2500 A/M	5000 A/m	10000 A/m
1	2	3	4	5	6	7	8	9	10	11
I	35C250		1.00	2.50	1.49	1.60	1.70	+ / - 17	2	7.60
II	35C270		1.10	2.70	1.49	1.60	1.70	+ / - 17	2	7.65
III	35C300	0.35	1.20	3.00	1.49	1.60	1.70	+ / - 17	3	7.65
IV	35C330		1.30	3.30	1.49	1.60	1.70	+ / - 17	3	7.65
V	35C360		1.45	3.60	1.49	1.60	1.70	+ / - 17	3	7.65
VI	50C270		1.10	2.70	1.49	1.60	1.70	+ / - 17	2	7.60
VII	50C290		1.15	2.90	1.49	1.60	1.70	+ / - 17	2	7.60
VIII	50C310		1.25	3.10	1 49	1.60	1.70	+ / - 14	3	7.65
IX	50C330		1.35	3.30	1.49	1.60	1.70	+ / - 14	3	7.65
X	50C350		1.50	3.50	1.50	1.60	1.70	+ / - 12	5	7.65
XI	50C400	0.50	1.70	4.00	1.53	1.63	1.73	+ / - 12	5	7.70
XII	50C470		2.00	4.70	1.54	1.64	1.74	+ / - 10	10	7.70
XIII	50C530		2.30	5.30	1.56	1.65	1.75	+ / - 10	10	7.70
X!V	50C600		2.60	6.00	1.57	1.66	1.76	+ / - 10	10	7.75
XV	50C630		2.8	6.3	1.55	1.65	1.76	+ / - 10	10	7.75
XVI	50C700		3.00	7.00	1.60	1.69	1.77	+ / - 10	10	7.80
XVII	50C800		3.60	8.00	1.60	1.70	1.78	+ / - 10	10	7.80
XVIII	65C330		1.35	3.3	1.49	1.6	1.7	+ / - 15	2	7.60
XIX	65C350		1.50	3.50	1.49	1.60	1.70	+ / - 14	2	7.60
XX	65C400		1.70	4.00	1.52	1.62	1.72	+ / - 14	2	7.65
XXI	65C470		2	4.7	1.53	1.63	1.73	+ / - 12	5	7.65
XXII	65C530	0.65	2.30	5.30	1.54	1.64	1.74	+ / - 12	5	7.70
XXIII	65C600		2.60	6	1.56	1.66	1.76	+ / - 10	10	7.75
XXIV	65C700		3	7	1.57	1.67	1.76	+ / - 10	10	7.75
XXV	65C800		3.60	8	1.60	1.70	1.78	+ / - 10	10	7.80
XXVI	65C1000		4.40	10	1.61	1.71	1.80	+ / - 10	10	7.85
XXVII	100C1000	1	4.40	10	1.58	1.68	1.76	+ / - 16	10	7.80
XXVII	100C1300		5.80	13.00	1.60	1.70	1.78	+ / - 6	10	7.80

Formerly most CRGO Mills were generally using the former AISI/ASTM nomenclature of M3, M4, M5 & M6 for designating the grade of CRGO Steel. However, now most standards follow a system where the CRGO nomenclature guarantees Watt Loss/Kg at 1.7 Tesla and 50Hz. Examples are as follows : IS - 3024: 2006 CRGO grades are designated as follows: One hundred times the nominal thickness in mm Material symbol CG (Conventional Grade) or HP (High Permeability) grades Guaranteed value of iron loss A value 100 times the iron loss at a frequency of 50 Hz and flux density of 1.7 Tesla IEC Standard Geneva Switzerland International Standard IEC-60404-8.7:2000 This international standard also has magnetic properties for conventional grade and high permeability grade similar to IS-3024:2006 Example of Conventional Grade, of IEC is M.120 27 S5 Example of high permeability grade of IEC is M.100 27 P5 Formerly most CRGO Mills were generally using the former AISI/ASTM nomenclature of M3, M4, M5 & M6 for designating the grade of CRGO Steel. However, now most standards follow a system where the CRGO nomenclature guarantees Watt Loss/Kg at 1.7 Tesla and 50Hz. Examples are as follows: One hundred times the nominal thickness in mm. Material symbol CG (Conventional Grade) or HP (High Permeability) grades. Guaranteed value of iron loss. A value 100 times the iron loss at a frequency of 50 Hz and flux density of 1.7 Tesla.

Common CRGO Standards Today

JAPANESE STANDARDS: - JIS C 2553:2000

Nippon Steel Corporation follows the same system. Examples are as follows: -

Orient Core:-	27 Z120 means 0.27mm thickness and watt loss of 1.2 w/kg. at
(Symbol Z)	1.7T/50Hz.
Orient Core HI-B:-	27 ZH 90 is a HI-B material, 0.27mm thick and watt loss of
(Symbol ZH)	0.90 watts/kg at 1.7T/50Hz.
Orient Core HI-B-LS:-	23 ZDKH 85 is a HI-B-laser scribed material with thickness 0.23mm and watt loss of 0.85 watts / kg. at 1.7 T

AMERICAN STANDARDS: - AISI:1983
American standards generally follow the AISI 1983 where Watt Losses are specified in Watts/Lb. at 60 Hz.
Even today the M series is the common nomenclature for conventional grades like M3, M4, M5, M6. For HI-B materials American nomenclature is MOH, M1H, M2H, M3H. AK Steel has also come out with TRAN COR DR (Domain Refined) laser scribed steel with following watt losses, (comparable to Nippon ZDKH)

Description	Thickness (mm)	Guaranteed Losses	Typical Watt Loss
		At1.7T/50Hz.	At1.7T/50Hz.
TRAN-COR-H0 DR	0.23	0.85	0.78
TRAN-COR H-1 DR	0.27	0.95	0.88
TRAN-COR-H-2 DR	0.3	1	0.95

EUROPEAN STANDARDS:- EN 10107 : 2005
This standard will generally be denoted by M followed by 3 digit number and thickness code and ending with S or R (S is for conventional grades and P is for HI-B grades.)

Example-M 130 27 S: will mean 0.27mm thick with watt loss of 1.30 Watts/Kg. at 1.7T/50 Hz. (conventional grade),
Similarly M103: will mean 0.27mm thick with watt loss of 1.03 Watts/Kg. at 1.7 T/50Hz. (HI-B grade).

RUSSIAN STANDARDS- GOST21427.1-83
The Russian standard is unique and different from other standards. Their Steel grades have 4 digit numbers ranging from 3404 to 3415. 3405 to 3408 are the most popular grades being used. Core losses are as follows:-

Thickness (mm)	Steel Grade	Max. Core Loss At 1.7 T/50Hz.
0.3	3405	1.4
0.3	3406	1.33
0.3	3407	1.26
0.3	3408	1.2
0.27	3405	1.38
0.27	3406	1.27
0.27	3407	1.2
0.27	3408	1.14

- Mitred Transformer Laminations
- Step Lap Laminations (All Types)
- Slit Coils

M-OH (0.27 mm)	M-4 (0.27 mm)

M-5 (0.30 mm)