Tool Joint Thread Chart

Custom Rotary Sub Adapters

Popular Sizes

The thread dimensions shown in the following chart are those that may be used to determine a thread type in the field. For specific details of the threads, please contact Mills Machine Co.

 MaterialPin DimensionsBox DimensionsThread
Tool Joint Name & Nominal SizeO.D.Make to Dia.Pin LengthPin IDPin Dia. @ BaseBox LengthBox Max IDTaperThread / InchThread Form
2 3/8" Reg.3 1/8" 3"1"2.625"3 1/4"1 3/4"3"5TAPER
2 7/8" Reg.3 3/4" 3 1/2"1 1/4"2.990"3 3/4"2"3"5TAPER
3 1/2" Reg.4 1/4"4 1/2"3 3/4"1 1/2"3.490"4"2 7/16"3"5TAPER
4 1/2" Reg.5 1/2" 4 1/4"2 1/4"4.600"4 1/2"3 1/4"3"5TAPER
5 1/2" Reg.6 3/4" 4 3/4"2 3/4"5.515"5"3 3/8"3"4TAPER
6 5/8" Reg.7 3/4"8"5"3 1/2"5.975"5 1/4"4 3/4"2"4TAPER
7 5/8" Reg.8 7/8"9"5 1/4"3 1/2"6.975"5 1/2"5 1/4"3"4TAPER
8 5/8" Reg.10" 5 3/8"4"7.951"6 1/4"6 5/8"3"4TAPER

API INTERNAL FLUSH (IF)

 MaterialPin DimensionsBox DimensionsThread
Tool Joint Name & Nominal SizeO.D.Make to Dia.Pin LengthPin IDPin Dia. @ BaseBox LengthBox Max IDTaperThread / InchThread Form
2" IF2 3/8 2 1/41 1/81.9752 3/41 1/224TAPER
2 3/8" IF3 1/2" 3"1 5/8"2.860"3 1/4"2 1/8"2"4TAPER
2 5/8" IF LH3 3/4" 3 1/4"1 3/4"3.128"3 5/8"2 1/4"2"4TAPER
2 7/8" IF4 1/8"4 1/2"3 1/2"2 1/8"3.385"3 3/4"2 1/2"2"4TAPER
3 1/2" IF4 3/4" 4"2 11/16"4.000"4 1/4"3 1/4"2"4TAPER
4" IF (4 1/2" XH)6" 4 1/2"3 1/4"4.828"4 3/4"3 1/2"2"4TAPER
4 1/2" IF (5" XH)6 1/8" 4 1/2"3 3/4"5.250"4 3/4"4"2"4TAPER
5 1/2" IF7 3/8" 5"4 13/16"6.390"5 1/2"5 1/16"2"4TAPER
6 5/8 IF9" 5"3 3/47.4595 5/86 1/424TAPER

API FULL HOLE (FH)

 MaterialPin DimensionsBox DimensionsThread
Tool Joint Name & Nominal SizeO.D.Make to Dia.Pin LengthPin IDPin Dia. @ BaseBox LengthBox Max IDTaperThread / InchThread Form
2 7/8" FH4 1/4"4 1/2"3 1/2"2 1/8" 3 7/8"2 1/8"3"5TAPER
3 1/2" FH4 5/8" 3 3/4"2 7/16"3.990"4"2 7/8"3"5TAPER
4" FH5 1/4" 4 1/2"2 13/16"4.270"4 3/4"3 1/4"2"4TAPER
4 1/2" FH5 3/4" 4"3"4.782"4 1/4"3 1/4"3"5TAPER
5 1/2" FH7" 5"4"5.828"5 1/2"4 1/4"2"4TAPER
6 5/8" FH8" 5"5"6.740"5 1/2"5 1/2"2"4TAPER

MAYHEW

 MaterialPin DimensionsBox DimensionsThread
Tool Joint Name & Nominal SizeO.D.Make to Dia.Pin LengthPin IDPin Dia. @ BaseBox LengthBox Max IDTaperThread / InchThread Form
JUNIOR (MJ)2 3/4" 2 1/4"1 1/4"2.320"2 1/2"1 11/16"2"4TAPER
REGULAR (MR)3 1/4" 3"1 1/2"2.555"3 1/4"2"1 1/2"4TAPER
FULLHOLE (MFH)3 3/4" 3 3/8"2"3.045"3 5/8"2 3/8"1 1/2"4TAPER

FAILING EXPLORATION

 MaterialPin DimensionsBox DimensionsThread
Tool Joint Name & Nominal SizeO.D.Make to Dia.Pin LengthPin IDPin Dia. @ BaseBox LengthBox Max IDTaperThread / InchThread Form
2 3/8" FEDP3 1/8" 2 3/4"1 3/8"2.480"3"1 3/4"2"4TAPER
2 7/8" FEDP3 3/4" 3 1/4"1 7/8"3.100"3 1/2"2 1/4"2"4TAPER

SQUARE THREAD & DCDMA THREADS

 MaterialPin DimensionsBox DimensionsThread
Tool Joint Name & Nominal SizeO.D.Make to Dia.Pin LengthPin IDPin Dia. @ BaseBox LengthBox Max IDTaperThread / InchThread Form
3 THREAD N ROD2 3/8" 2 3/4"1"1.860"3"1 5/8" 3SQUARE
4 THREAD N ROD2 3/8" 2 3/4"1"1.865"3"1 5/8" 4SQUARE
A ROD1 5/8" 1 7/8"9/16"1.260"2 1/8"1 1/16" 3SQUARE
AW ROD1 3/4" 1 7/8"5/8"1.365"2 1/8"1 1/4" 3SQUARE
AWJ (AWML)1 3/4" 1 3/4"5/8"1.425"1 7/8"1"2"5TAPER
E ROD1.305" 1 3/4"7/16"0.996"2"7/8" 3SQUARE
B W2 3/8" 2 1/4"3/4"1.680"2 5/8"1 3/8" 3SQUARE
BQ2 3/16" 4 3/4"1 13/16" 2"1 13/16"1/2"3TAPER
HW3 1/2" 3 1/4"2 1/4" 3 1/2"2 13/16" 3SQUARE
EW1 3/8" 1 9/16"7/16"1.050"1 3/4"7/8" 3SQUARE
NW2 5/8" 2 3/4"1 3/8"2.210"3"2" 3SQUARE
NWJ (NWML)2 5/8" 2 3/8"1 1/4"2.240"2 3/4"1 1/2"2"4TAPER

Other Sizes

API X-HOLE (XH)

 MaterialPin DimensionsBox DimensionsThread
Tool Joint Name & Nominal SizeO.D.Make to Dia.Pin LengthPin IDPin Dia. @ BaseBox LengthBox Max IDTaperThread / InchThread Form
3 1/2" XH4 7/8" 3 1/2"2 7/16"3.800"3 7/8"2 7/8"2"4TAPER
4 1/2" XH6" 4 1/2"3 1/4"4.828"4 3/4"3 1/2"2"4TAPER
5" XH6 1/8" 4 1/2"3 3/4"5.250"4 3/4"4"2"4TAPER

HACKER

 MaterialPin DimensionsBox DimensionsThread
Tool Joint Name & Nominal SizeO.D.Make to Dia.Pin LengthPin IDPin Dia. @ BaseBox LengthBox Max IDTaperThread / InchThread Form
JUNIOR3 1/8" 2 1/4"1 7/8"2.685"2 3/4"2 1/8"1 3/4"5TAPER
SENIOR3 1/2" 2 1/2"1 3/4"2.895"2 3/4"2 1/4"1 1/2"4TAPER
4" HACKER5 7/8" 3 5/8"3 3/4"5.215"4"4 3/8"1 1/2"4TAPER
6 5/8" HACKER7 1/2" 3 1/16"6"6.935"3 1/2"6 1/4"1 1/2"4TAPER
8 5/8" HACKER10 1/2" 4 1/2"7 1/2"9.460"5"8"2"4TAPER

BECO

 MaterialPin DimensionsBox DimensionsThread
Tool Joint Name & Nominal SizeO.D.Make to Dia.Pin LengthPin IDPin Dia. @ BaseBox LengthBox Max IDTaperThread / InchThread Form
3 1/2" BECO4 3/4" 3 3/4"1 1/2"3.970"4 1/4"2 1/4"3"2TAPER
4 1/2" BECO5 3/4" or 6 1/2" 4 1/4"2 1/4"5.000"5"3 1/4"3"2TAPER
5 1/4" BECO7" 5 3/4"2 13/16"5.750"5 1/2"3 3/4"3"2TAPER
6" BECO7 5/8" or 8 3/4" 6 1/2"3"6.500"5 1/2"+4 1/2"3"2TAPER
8" BECO10 3/4" or 12 3/4" 4 7/8"5"8.500"5 1/2"+6 1/4"3"2TAPER

CA-21 (DEEP ROCK)

 MaterialPin DimensionsBox DimensionsThread
Tool Joint Name & Nominal SizeO.D.Make to Dia.Pin LengthPin IDPin Dia. @ BaseBox LengthBox Max IDTaperThread / InchThread Form
CA 212 1/4" 1 1/4"1 1/8"1.765"1 1/2"1 1/2"1 1/2"6TAPER

E U E

 MaterialPin DimensionsBox DimensionsThread
Tool Joint Name & Nominal SizeO.D.Make to Dia.Pin LengthPin IDPin Dia. @ BaseBox LengthBox Max IDTaperThread / InchThread Form
3/4" (1.050" API)1.560" 1 1/8"1.315"0.825"1 3/8" 3/4"10TAPER
1" (1.315" API)1.900" 1 1/4"1.469"1.049"1 1/2" 3/4"10TAPER
1 1/4" (1.660" API)2.200" 1 3/8"1.825"1.380"1 3/4"1 1/2"3/4"10TAPER
1 1/2" (1.900" API)2.500" 1 7/16"2.093"1.610"1 7/8"1 3/4"3/4"10TAPER
2" (2 3/8" API)3.063" 1 15/16"2.625"1.995"2 3/8"2 1/4"3/4"8TAPER
2 1/2" (2 7/8" API)3.668" 2 1/8"3.113"2.441"2 1/2"2 1/2"3/4"8TAPER
3" (3 1/2" API)4.500"2 3/8" 3.795"2.992"2 3/4"3 5/16"3/4"8TAPER
3 1/2" (4" API)5.000" 2 1/2"4.250"3.476"2 7/8" 3/4"8TAPER
4" (4 1/2" API)5.563" 2 5/8"4.790"3.958"3" 3/4"8TAPER

HACKER FAILING

 MaterialPin DimensionsBox DimensionsThread
Tool Joint Name & Nominal SizeO.D.Make to Dia.Pin LengthPin IDPin Dia. @ BaseBox LengthBox Max IDTaperThread / InchThread Form
6 5/8" HF8" 3 1/2"6"7.310"4 1/2"6 1/2"1.5"4TAPER

MOBILE

 MaterialPin DimensionsBox DimensionsThread
Tool Joint Name & Nominal SizeO.D.Make to Dia.Pin LengthPin IDPin Dia. @ BaseBox LengthBox Max IDTaperThread / InchThread Form
2 5/8" MOBILE2 5/8" 2 1/2"1 1/4"2.240"2 7/8"1 3/4"2"5TAPER

NATIONAL PIPE THREAD

 MaterialPin DimensionsBox DimensionsThread
Tool Joint Name & Nominal SizeO.D.Make to Dia.Pin LengthPin IDPin Dia. @ BaseBox LengthBox Max IDTaperThread / InchThread Form
1" NPT1 3/4" 1"1"1.325"1 1/4"1 1/8"3/4"11 1/2TAPER
1" NPT LH1 3/4" 1"1"1.325"1 1/4"1 1/8"3/4"11 1/2TAPER
1 1/4" NPT2" 1"1 1/4"1.660"1 1/4"1 3/8"3/4"11 1/2TAPER
1 1/2" NPT2 1/4" 1 1/8"1 1/2"1.950"1 3/8"1 5/8"3/4"11 1/2TAPER
2" NPT2 3/4" 1 1/8"2"2.385"1 5/8"2 1/8"3/4"11 1/2TAPER
2" NPT LH2 3/4" 1 1/8"2"2.3851 5/8"2 1/8"3/4"11 1/2TAPER
2 1/2" NPT3 1/4" 1 9/16"2 1/2"2.875"1 3/4"2 5/8"3/4"8TAPER
3" NPT4" 1 5/8"3"3.500"1 7/8"3 1/8"3/4"8TAPER
3" NPT LH4" 1 5/8"3"3.500"1 7/8"3 1/8"3/4"8TAPER
3 1/2" NPT4 5/8" 1 11/16"3 1/2"4.000"2 1/16"3 5/8"3/4"8TAPER
3 1/2" NPT LH4 5/8" 1 11/16"3 1/2"4.000"2 1/16"3 5/8"3/4"8TAPER
4" NPT5 1/4" 1 3/4"4"4.510"2 1/4"4 1/8"3/4"8TAPER
4" NPT LH5 1/4" 1 3/4"4"4.510"2 1/4"4 1/8"3/4"8TAPER
4 1/4" NPT   4 1/4"4.250"  3/4"8TAPER
5" NPT6 5/16" 2"5"5.563"2 1/2"5 1/4"3/4"8TAPER
6" NPT7 3/8" 2"6"6.625"2 1/2"6 1/4"3/4"8TAPER

PK RED DEVIL

 MaterialPin DimensionsBox DimensionsThread
Tool Joint Name & Nominal SizeO.D.Make to Dia.Pin LengthPin IDPin Dia. @ BaseBox LengthBox Max IDTaperThread / InchThread Form
P K Red Devil2 7/8" 3 7/8"1 3/8"2.300"4 1/4"1 7/8"3/4"8TAPER

ROCKMASTER

 MaterialPin DimensionsBox DimensionsThread
Tool Joint Name & Nominal SizeO.D.Make to Dia.Pin LengthPin IDPin Dia. @ BaseBox LengthBox Max IDTaperThread / InchThread Form
ROCKMASTER2 3/4" 3"1 1/8"2.030"3 1/4"1 3/4" 3ACME

WINTER WEISS

 MaterialPin DimensionsBox DimensionsThread
Tool Joint Name & Nominal SizeO.D.Make to Dia.Pin LengthPin IDPin Dia. @ BaseBox LengthBox Max IDTaperThread / InchThread Form
2 3/8" WW Mod.3 1/4" 3"1 1/2"2.535"3 1/4"2"1.5"4TAPER
2 7/8 WW Mod.3 7/16" 3"1 1/2"2.535"3 1/4"2"1.5"4TAPER