NEMA and IEC Standard Taper and Connection Sizes for Graphite / Carbon Electrodes

Material Specifications and Characteristics

The following are standard of NEMA & IEC 3, 4 TPI Taper standards, and male / female size connection sizes for Manufactured graphite and carbon electrodes.

3 TPI Taper Connecting Rod

Electrode Nominal Diameter
Diameter (Maximum)
Length (Maximum)

in.

mm

in.

mm

in.

mm

9

225

5.5

139.7

8

203.2

10

250

5.5

139.7

8

203.2

10

250

6.125

155.58

8.667

220.13

12

300

6.125

155.58

8.667

220.13

12

300

6.975

177.17

10.667

270.93

14

350

6.975

177.17

10.667

270.93

14

350

8.5

215.9

12

304.8

16

400

8.5

215.9

12

304.8

16

400

9.5

241.30

14

355.6

18

450

9.5

241.30

14

355.6

18

450

10.75

273.05

14

355.6

20

500

10.75

273.05

14

355.6

20

500

10.75

273.05

18

457.2

4 TPI Taper Connecting Pin

Nominal Diameter of Electrode

Diameter (Maximum)

Length (Maximum)

in.

mm

in.

mm

in.

mm

3

75

1.8125

46.04

3

76.2

4

100

2.75

69.85

4

101.6

5.125

130

3.125

79.38

5

127

6

150

3.625

92.08

5.5

139.7

7

175

4.25

107.95

6.5

165.1

8

200

4.813

122.24

7

177.8

9

225

5.5

139.7

7

177.8

9

225

5.5

139.7

8

203.2

10

250

6

152.4

7.5

190.5

12

300

7

177.8

8.5

215.9

14

350

8

203.2

10

254

14

350

8.75

222.25

14

355.6

16

400

8.75

222.25

14

355.6

18

450

10.625

269.88

14

355.6

18

450

10.625

269.88

18

457.2

20

500

10.625

269.88

14

355.6

20

500

10.625

269.88

18

457.2

20

500

11.75

298.45

18

457.2

24

600

12.5

317.5

14

355.6

24

600

12.5

317.5

18

457.2

28

700

9.5

374.65

18

457.2

28

700

14.75

374.65

22

558.8

Male / Female

Nominal Diameter of Electrode
Male End
Female End
Length
Pitch Diameter
Socket Depth
Pitch Diameter
in.
mm
in
mm
in.
mm
in
mm
in.
mm
7
175
4.112
104.44
2.931
74.45
4.313
109.54
6.30
160.02
8
200
4.688
119.06
3.329
84.55
4.813
122.24
7.167
182.04
9
225
5.188
131.76
3.779
95.99
5.313
134.94
8.08
205.23
10
250
5.668
144.46
4.112
104.44
5.813
147.64
8.88
225.55