API COUPLING STANDARD SIZES AND LENGTHS 

LTC

Coupling Size Coupling Size (Decimal) Standard Coupling Length 4 1/2 5.000 7.000

5 5.563 7.750

5 1/2 6.050 8.000

6 5/8 7.390 8.750

7 7.656 9.000

7 5/8 8.500 9.250

8 5/8 9.625 10.000

9 5/8 10.625 10.500

STC

Coupling Size Coupling Size (Decimal) Standard Coupling Length 4 1/2 5.000 6.250

5 5.563 6.500

5 1/2 6.050 6.750

6 5/8 7.390 7.250

7 7.656 7.250

7 5/8 8.500 7.500

8 5/8 9.625 7.750

9 5/8 10.625 7.750

10 3/4 11.750 8.000

11 3/4 12.750 8.000

13 3/8 14.375 8.000

16 17.000 9.000

20 21.000 9.000

NUE

Coupling Size Coupling Size (Decimal) Standard Coupling Length 2 3/8” 2.875 4.500

2 7/8” 3.500 5.500

3 ½” 4.250 5.625

4 ½” 5.200 6.500

EUE

Coupling Size Coupling Size (Decimal) Standard Coupling Length 2 3/8 3.063 4.875

2 7/8 3.668 5.500

3 1/2 4.500 5.750

4 1/2 5.563 6.500

Modified BTC

Coupling Size Coupling Size (Decimal) Standard Coupling Length 2 3/8 2.875 8.500

2 7/8 3.500 8.500

3 1/2 4.250 8.500

4 1/2 5.200 9.500

 

BTC

Coupling Size Coupling Size (Decimal) Standard Coupling Length 4 1/2 5.000 8.875

5 5.563 9.125

5 1/2 6.050 9.250

6 5/8 7.390 9.625

7 7.656 10.000

7 5/8 8.500 10.375

8 5/8 9.625 10.625

9 5/8 10.625 10.625

10 3/4 11.750 10.625

11 3/4 12.750 10.625

13 3/8 14.375 10.625