Graphite Electrodes HD 350-450mm

Graphite electrodes HD 350 - 450 mm are made of mixed petroleum coke and coal pitch, to be extruded, baked, impregnated, graphitized and machined for use as conductive material on EAF (Electric Arc Furnace) and LF (Ladle Furnace) for steelmaking.
In the steelmaking process, the EAF method recycles used iron scrap by melting it at a temperature of about 1600 ℃ in an electric arc furnace. Graphite electrodes, a kind of conductor, are an essential component in this kind of furnace.
Standards
IEC 60239 Graphite electrodes for electric arc furnaces – Dimensions and designation
YB/T 142-2012 High Density graphite electrode
Properties

Property	Unit	Electrode Diameter
		HD 350～450 mm (14～18 inch)
Bulk Density	g/cm3	1.64 ~ 1.72
Specific Resistance	μΩm	5.4 ~ 6.6
Flexural Strength	MPa	10.0 ~ 15.0
Elastic Modulus	GPa	9.0 ~ 12.0
Coefficient of Thermal Expansion	×10-6/°C	1.9 ~ 2.3
Ash Content	%	Less than 0.2

Diameters and Lengths of Electrodes

Nominal Diameter of Electrodes		IEC Designation of Joint	Pin			Socket
			Major Diameter	Pitch Diameter	Length	Minor Diameter	Pitch Diameter	Depth
			d1	d2	l1	d3	d4	l2
mm	(inch)	Type T3	mm	mm	mm	mm	mm	mm
350	(14)	215T3N	215.90	211.69	304.80	207.47	211.69	158.40
400	(16)	215T3N	215.90	211.69	304.80	207.47	211.69	158.40
400	(16)	241T3N	241.30	237.09	338.70	232.87	237.09	175.30
450	(18)	241T3N	241.30	237.09	338.70	232.87	237.09	175.30
450	(18)	273T3N	273.05	268.84	355.60	264.62	268.84	183.80
Notes: Type T3 is 3 taper threads per inch, pitch 8.47 mm. Pin pitch diameter is equal to socket pitch diameter (d2 = d4). Socket minor diameter is equal to pitch diameter (d3 = d4 – 4.22).

Dimensions of Pins and Sockets (T4)

Nominal Diameter of Electrodes		IEC Designation of Joint	Pin			Socket
			Major Diameter	Pitch Diameter	Length	Minor Diameter	Pitch Diameter	Depth
			d1	d2	l1	d3	d4	l2
mm	(inch)	Type T4	mm	mm	mm	mm	mm	mm
350	(14)	203T4N	203.20	200.04	254.00	196.88	200.04	133.00
400	(16)	222T4N	222.25	219.09	304.80	215.93	219.09	158.40
400	(16)	222T4L	222.25	219.09	355.60	215.93	219.09	183.80
450	(18)	241T4N	241.30	238.14	304.80	234.98	238.14	158.40
450	(18)	241T4L	241.30	238.14	355.60	234.98	238.14	183.80
Notes: Type T4 is 4 taper threads per inch, pitch 6.35 mm. Pin pitch diameter is equal to socket pitch diameter (d2 = d4). Socket minor diameter is equal to pitch diameter (d3 = d4 – 3.16).

Tolerances for Sockets and Pins

Dimension	Tolerances for Sockets and Pins (tolerance in brackets are informative only)
	Min	Max
	(mm)	(mm)
Length of pin l1	(-4)	0
Depth of socket l2	-3	(+10)
Length of thread l3	-2	(+8)
Recess of pin l4	0	+10
Recess of socket l5	0	+4
Pitch diameter of pin d2	(-1)	0
Pitch diameter of socket d4	0	(+0.5)

Designation
Electrodes shall be designated by the nominal diameter, the nominal length and the socket designation.
EXAMPLE 1 Designation of electrodes with normal sockets:
350 × 2100 × 203T4N
EXAMPLE 2 Designation of electrodes with long sockets:
400× 2100 × 222T4L