Graphite electrodes and nipples

Graphite electrodes of EG/RP grade are used in electric arc, refining, ferroalloy and submerged-arc furnaces

Properties	Units of measurement	Typical values
Diameter	mm	75-150	200-350	400-600	700
Bulk density	g/cm³	1.61	1.61	1.61	1.58
Ash impurities	%	0,2	0,2	0,3	0,3
Specific electrical resistance	µОhm•m	8.0	8.0	8.0	8.5
Linear thermal expansion coefficient, (20-520)ºС	10^-6 •1/°С	2.4	2.4	2.4	2.5
Flexural strength	MPa	11	11	9	8
Modulus of elasticity (Young's modulus)	GPa	9	7	7	7

Graphite electrodes of EGP/ HP grade are used in high power electric arc furnaces and ladle furnaces

Properties	Units of measurement	Typical values
Diameter	mm	200-350	400-500
Bulk density	g/cm³	1.70	1.70
Ash impurities	%	0.2	0.2
Specific electrical resistance	µОhm•m	6.5	6.5
Linear thermal expansion coefficient, (20-520)ºС	10^-6 •1/°С	2.4	2.4
Flexural strength	MPa	16	14
Modulus of elasticity (Young's modulus)	GPa	9	9

Graphite electrodes of EGSP/ UHP grade are used in ultra high power electric arc furnaces and ladle furnaces

Properties	Units of measurement	Typical values
Diameter	mm	350-450	500-650
Bulk density	g/cm³	1.72	1.70
Ash impurities	%	0.2	0.2
Specific electrical resistance	µОhm•m	6.0	5.1
Linear thermal expansion coefficient, (20-520)ºС	10^-6 •1/°С	2.1	1.3
Flexural strength	MPa	15	12
Modulus of elasticity (Young's modulus)	GPa	10	11

Nipples for graphite electrodes

Properties	Units of measurement	Typical values
Diameter	mm	75-150	200-350	400-550	600-700
Bulk density	g/cm³	1.68	1.77	1.80	1.82
Ash impurities	%	0.2	0.2	0.2	0.2
Specific electrical resistance	µОhm•m	5.5	4.5	4.2	4.0
Linear thermal expansion coefficient, (20-520)ºС	10^-6 •1/°С	2.2	1.1	1.2	1.1
Flexural strength	MPa	16	17	22	23
Modulus of elasticity (Young's modulus)	GPa	-	17	17	18

Note: the above values are average values and they do not constitute a specification

Sizes of graphite electrodes

Allowable lengths of graphite electrodes

Nominal length, mm	Allowable normal electrode length, mm		Allowable short electrode length, mm
Nominal length, mm	maximum	minimum	maximum	minimum
1000	1050	925	925	800
1200	1250	1100	1100	975
1500	1600	1400	1400	1225
1800	1900	1700	1700	1525
2100	2225	1975	1975	1825
2400	2525	2275	2275	2125
2700	2900	2550	2550	2400

Sizes of graphite nipples and electrode sockets with Т4 taper thread

Note: Nipple effective diameter d2 is equal to electrode socket effective diameter d4

Other combinations of the nominal diameter and the joint are to be agreed upon with a consumer

Sizes of graphite nipples and electrode sockets with Т3 taper thread

Note: Nipple effective diameter d2 is equal to electrode socket effective diameter d3

Sizes of graphite nipples and electrode sockets with cylindrical thread 3 turns per inch (С3)

Note: Nipples from 75 mm to 200 mm in diameter are made without holes for plugs.

Recommended tightening torque when joining electrodes

Nominal electrode diameter, mm	Tightening torque, N∙m
75	30
100	50
125	90
150	130
175	200
200	250
225	350
250	450
300	650
350	850
400	1100
450	1500
500	2500
550	3500
600	4000
650	5000
700	6000

Recommended current loads of graphite electrodes.

Nominal diameter, mm	Allowable current density, A/cm²
Nominal diameter, mm	EG	EGP	EGSP
150	18-25	-	-
200	18-25	20-30	25-35
250	15-20	20-25	25-35
300	15-20	20-25	25-35
350	15-20	20-25	25-35
400	15-18	18-22	25-30
450	15-18	18-22	25-30
500	15-18	18-22	22-28
550	15-18	18-22	22-28
600	10-15	15-20	22-28
650	-	-	20-26
700	12	-	19-25

Note: for ladle furnace installations specified current loads may be in excess of 10 %.