The six-party drill pipe is made from AISI4145HMOD alloy steel According to API Spec.7 -1. IT is formed by hot forged and fully heat-treated by intermediate frequency induction heat treatment or 20m horizontal optical resistance furnace to threads are phosphated, copperrized or cold worked.
  Standard size of hexagonal kelly;Each can reach a total length of 27 meters.
Kelly size Length drive section Length overall Length drive section
LD
Standard LD
Optional L
standard L
optional DFL
Across flate DC
Across cornere DCC
Across cornere Rc
Radlue Rcc
Radlue Wall thickness eccentric bore

76.2 3 11280 12190 76.2 85.7 85.73 6.4 42.9 12.1
88.9 3 1/2 11280   12190 88.9 100.8 100.0 6.4 50.0 13.3
108.0 4 1/4 11280 15540 12190 16460 108.0 122.2 121.4 9.9 60.7 15.9  
133.4 5 1/4 11280 15540 12190 16460 133.4 151.6 149.86 9.9 75.0 15.9  
133.4 5 1/4 11280 15540 12190 16460 133.4 175.4 171.45 15.9 85.7 15.88
152.4 6 11280 15540 12190 16460 152.4 173.0 173.02 9.5 86.5 15.9  
152.4 6 11280 15540 12190 16460 152.4 173.0 173.02 9.5 86.5 15.9  


Upper box connection
Thread size and style LF O.D. Bevel diameter
Standard optional DU
standard DU
optional LU DF
Standard DF
optional
6 5/8 REG 4 1/2 REG 196.9 146.1 406.4 186.1 134.5
6 5/8 REG 4 1/2 REG 196.9 146.1 406.4 186.1 134.5
6 5/8 REG 4 1/2 REG 196.9 146.1 406.4 186.1 134.5
6 5/8 REG 196.9   406.4 186.1  

Lower pin connection I.D.

Label O.D. LL DF
Bevel diameter

NC26 85.7 508 82.9 31.8  
NC31 104.8 508 100.4 44.5
NC38 120.7 508 116.3 57.2
NC46 158.8 508 145.3 71.4
NC50 161.9 508 154.0 71.4
5 1/2 FH 177.8 508 170.7 82.6
NC56 177.8 508 171.7 82.6