Threading, Gauging, and Inspection of Casing, Tubing, and Line Pipe Threads

API SPECIFICATION 5B

SIXTEENTH EDITION, DECEMBER 2017

ERRATA 1, JUNE 2018

ERRATA 2, NOVEMBER 2018

ADDENDUM 1, DECEMBER 2018

(API MONOGRAM PROGRAM EFFECTIVE DATE: JULY 1, 2019)

ADDENDUM 2, NOVEMBER 2019

(API MONOGRAM PROGRAM EFFECTIVE DATE: MAY 1, 2020)

ADDENDUM 3, JANUARY 2021

(API MONOGRAM PROGRAM EFFECTIVE DATE: AUGUST 1, 2021)

Special Notes

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Copyright © 2017 American Petroleum Institute

Foreword

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• the term “shall” denotes a minimum requirement in order to conform to the standard;

  
  

• the term “should” denotes a recommendation or that which is advised but not required in order to conform to the standard;

  
  

• the term “may” is used to express permission or a provision that is optional; and

  
  

• the term “can” is used to express possibility or capability.

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Suggested revisions are invited and should be submitted to the Standards Department, API, 200 Massachusetts Avenue, NW, Suite 1100, Washington, DC 20001, standards@api.org.

iii

Contents

Page

1. Scope 1

   1. Coverage—Threading and Gauging 1

   2. Coverage—Inspection 1

   3. Application of the API Monogram 1

   4. Other Applications 1

2. Normative References 1

3. Terms, Definitions, and Abbreviations 2

   1. Terms and Definitions 2

   2. Abbreviations 6

4. Thread Dimensions and Tolerances—Line Pipe, Round Thread Casing and Tubing, and Buttress Thread Casing 7

   1. Thread Measurement 7

   2. Visual Inspection 7

   3. Thread Precision 8

   4. Thread Design 8

   5. Chamfer 9

   6. Internal Thread 9

   7. Thread Finish 9

   8. Thread Control 9

   9. Thread Elements 9

   10. Misalignment 9

   11. Misalignment Tests (Options) 10

   12. Misalignment Rejects (Purchaser Option) 10

   13. Full Crested Thread Length 10

   14. Rounded Nose 10

5. Thread Inspection 34

   1. Line Pipe, Round Thread Casing and Tubing, and Buttress Thread Casing Precautions 34

   2. Location of Measurements 34

   3. Taper Measurement 37

   4. Lead Measurement 41

   5. Height and Addendum Measurement 43

   6. Angle and Thread Form Measurement 51

   7. Single Dial Buttress Thread Form Gauge 53

   8. Coupling Thread Alignment 54

   9. Calibration of Instruments and Dial Gauges 57

6. Diameter, Ovality, and Size Gauging Practice 58

   1. Line Pipe, Round Thread Casing and Tubing, and Buttress Thread Casing 58

7. Gauge Specification 72

   1. Line Pipe, Round Thread Casing and Tubing, and Buttress Thread Casing 72

8. API Gauge Certification 91

   1. Line Pipe, Round Thread Casing and Tubing, and Buttress Thread Casing 91

9. Thread Marking 92

Annex A (informative) API Monogram Program, Use of the API Monogram by Licensees 94

Annex B (informative) Supplementary Requirements 98

v

Contents

Page

Annex C (informative) Instructions for Shipment of Master Gauges 104

Bibliography 105

Figures

1. Basic Dimensions of Buttress Threads Hand-tight Make-up 11

2. Buttress Casing Thread Form and Dimensions (Casing sizes 41/2 in. through 133/8 in.) 12

3. Buttress Casing Thread Form and Dimensions (Casing sizes 16 in. and larger) 13

4. Basic Dimensions of Line Pipe Hand-tight Make-up 13

5. Basic Dimensions of Casing Round Threads Hand-tight Make-up 14

6. Casing Round Thread Dimensions 15

7. Casing Round Thread Form 15

8. Basic Dimensions of Tubing Round Threads Hand-tight Make-up 16

9. Round Nose Ends 16

10. Line Pipe Thread Form 17

11. Tubing Round Thread Form 17

12. 8 Round Tubing Thread Dimensions 18

13. 10 Round Tubing Thread Dimensions 18

14. Measuring Interval (8-round Tubing Pin) 35

15. Measuring Interval (8-round Coupling) 35

16. Measuring Interval (Buttress Pin) 36

17. Measuring Interval (Buttress Coupling) 36

18. External Thread Taper Measurements (Gauge Set near First Perfect Thread) 38

19. External Thread Taper Measurements (Measurement at Last Perfect Thread) 38

20. Buttress Thread Run-out Measurements 39

21. Internal Thread Taper Measurements 39

22. Internal Taper Measurements (41/2 in. and smaller) 40

23. Internal Lead Gauge on Standard Template 42

24. Lead Gauge on Pin Thread 42

25. Lead Gauge on Coupling Thread 43

26. Thread Height Contact Point (Round Thread Height Gauge) 44

27. Thread Height Contact Point (Buttress Thread Height) 44

28. External Addendum Contact Point (Round Thread Addendum Gauge) 44

29. Internal Thread Height Gauge on Setting Standards (Buttress Thread Height Gauge on Block) 46

30. Internal Thread Height Gauge on Setting Standards (8R and 10R Thread Height Gauge on Block) . . . 46

31. Internal Addendum Gauge on Setting Standards (8R and 10R Addendum Gauge on Block) 47

32. External Thread Height Gauge on Setting Standards (Buttress Thread Height Gauge on Block) 47

33. External Thread Height Gauge on Setting Standards (8R and10R Thread Height Gauge on Block) . . . 47

34. External Addendum Gauge on Setting Standards (8R and 10R Addendum Gauge on Block) 48

35. Round Thread Height Gauge Setting Standard (Thread Addendum Standard) 48

36. Round Thread Height Gauge Setting Standard (Thread Height Standard) 48

37. Buttress Height Gauge Setting Standard (1 in. TPF Buttress Thread Height Standard) 49

38. Round Thread Height Gauge Setting Standard (3/4 in. TPF Buttress Thread Height Standard) 49

39. External Addendum Gauge on Pin Threads (Round Thread Addendum Gauge) 49

40. External Thread Height Gauge on Pin Threads (Round Thread Height Gauge) 50

41. External Thread Height Gauge on Pin Threads (Buttress Thread Height Gauge) 50

42. Internal Thread Height Gauge on Coupling Threads (Round Thread Height Gauge) 50

43. Internal Addendum Gauge on Coupling Threads (Round Thread Addendum Gauge) 51

44. Internal Thread Height Gauge on Coupling Threads (Buttress Thread Height Gauge) 51

    vi

    Contents

    Page

    Figures (continued)

45. External Thread Form Overlays for 8 Round Threads 52

46. External Thread Form Overlays for Buttress Threads 52

47. External Thread Form Overlays for Buttress Threads (Measured from Root) 53

48. Buttress Tooth Width Gauge (Measured from Thread Crest) 53

49. Buttress Groove Width Gauge 54

50. Equipment for Measuring Coupling Alignment and Concentricity 55

51. Coupling Alignment Gauge 55

52. Coupling Alignment Inspection 56

53. Coupling Alignment Inspection (Detail) 56

54. External Thread Crest Diameter Gauge Location 59

55. Internal Thread Crest Diameter Gauge Location 59

56. Average Crest Diameter 60

57. Ovality 60

58. 8 Round Casing Thread Ring Standoff 65

59. 8 Round Casing Thread Plug Standoff 65

60. Gauging Practice for Line Pipe Threads, Casing, and Tubing Round Thread Hand-tight Assembly . . . 67

61. Gauging Practice for Buttress Casing Threads Hand-tight Assembly 68

62. Comparison of Line Pipe Gauges Made Subsequent to 1940 and Gauges Made Prior to 1940 71

63. Thread Gauge for Line Pipe and Round Thread Casing and Tubing

    (Taper sizes 41/2 in. through 133/8 in.) 86

64. Thread Gauge for Buttress Casing 87

65. Gauge Thread Form for Line Pipe and Round Thread Casing and Tubing 87

66. Gauge Thread Form and Dimensions for Buttress Casing (Taper sizes 41/2 in. through 133/8 in.) 88

67. Gauge Thread Form and Dimensions for Buttress Casing (Taper sizes 16 in. and larger) 89

68. Bolt Circles and Back-up Plate Dimensions for Line Pipe, Buttress Casing and

Short or Long Round Casing Master Plug Gauges 90

1. Basic Dimension of Power Tight Make-up 98

2. SR 22 Casing Round Thread Form (API 8-Round Internal Threadform) 103

3. SR 22 Casing Round Thread Form (API 8-Round External Threadform) 103

4. SR 22 Casing Round Thread Form (API 8-Round Mated Threadform) 103

vii

Contents

Tables

Page

1. Casing Short-thread Dimensions 19

2. Tolerances on Buttress Casing Thread Dimensions 21

3. Line Pipe Thread Dimensions 23

4. Casing Long-thread Dimensions 24

5. Buttress Casing Thread Dimensions 25

6. Non-upset Tubing Thread Dimensions 26

7. External-upset Tubing Thread Dimensions 27

8. External-upset Long Round Thread Dimensions for Fiberglass Pipe 28

9. Integral-joint Tubing Thread Dimensions 28

10. Round Nosed Ends 29

11. Casing Round Thread Height Dimensions 29

12. Tolerances on Casing Round Thread Dimensions 30

13. Line Pipe Thread Height Dimensions 31

14. Tolerances on Line Pipe Dimensions 31

15. Tubing Round Thread Height Dimensions 32

16. Tolerances on Tubing Round Thread Dimensions 32

17. Contact Point Dimensions for Taper and Run-out Gauges 37

18. Contact Point Dimensions for Lead Gauge 41

19. Compensated Thread Lengths for Measurements Parallel to the Taper Cone 42

20. Contact Point Dimensions for Addendum Gauge 45

21. Thread Height Groove Check Blocks 45

22. Buttress Thread Height Groove Check Blocks 45

23. Thread Addendum Groove Check Blocks 45

24. Dial Gauge Error Check 57

25. Thread Ovality Maximum for Standoff 62

26. Max Allowable Standoff for Given Values of Thread Ovality (3/4 in. TPF) 63

27. Max Allowable Standoff for Given Values of Thread Ovality (1 in. TPF) 64

28. Standoff Tolerances 69

29. Gauge Standoff Tolerance for Acceptance 70

30. Gauge Standoff Correction Factor 71

31. Line Pipe Thread Gauge Dimensions 74

32. Short and Long Round Casing Thread Gauge Dimensions 75

33. Buttress Casing Thread Gauge Dimensions 76

34. Non-upset Tubing Thread Gauge Dimensions 77

35. External-upset Tubing Thread Gauge Dimensions 78

36. Integral-joint Tubing Thread Gauge Dimensions 79

37. Gauge Thread Height Dimensions for Line Pipe 80

38. Gauge Thread Height Dimensions for Round Thread Casing and Tubing 80

39. Tolerances on Gauge Dimensions for Line Pipe 81

40. Tolerances on Gauge Dimensions for Round Thread Casing and Tubing 82

41. Tolerances on Gauge Dimensions for Buttress Casing 83

1. Enhanced Leak Resistance LTC Thread Dimensions 100

2. Dimensional Tolerances on SR 22 Casing 8-Round Thread Dimensions 102

viii

Threading, Gauging, and Inspection of Casing, Tubing, and Line Pipe Threads

1. Scope

   1. Coverage—Threading and Gauging

      
      

      This specification covers dimensions, tolerances, and marking requirements for API threads and the gauges that control the acceptance criteria for the threads. Thread element gauges, instruments, and requirements for the inspection of threads for line pipe, round thread casing, round thread tubing, and buttress casing connections are included. Thread dimensions shown without specifications (or shown as NA) are not subject to inspection of diameter, ovality, and addendum. Thread dimensions shown without tolerances are related to the basis for connection design and are not subject to measurement to determine acceptance of product.

      
      

   2. Coverage—Inspection

      
      

      Thread inspection applies at the point of manufacture prior to shipment, to inspection at some intermediate point, to inspection subsequent to delivery at destination, and to inspection by inspectors representing the purchaser or the manufacturer. The manufacturer may, at his or her option, use other instruments or methods to control manufacturing operations; but acceptance and rejection of the product is determined by the results of inspection made in accordance with the requirements of this specification.

      
      

      Thread inspection is performed using instruments designed to measure either the functional relationship of multiple thread elements or measure an individual thread element. The inspection requirements include measurements of standoff, diameter, ovality, addendum, taper, lead, height, and angle of thread that are applicable to threads having 111/2 or less turns per inch (0.45 or less turns per mm). Ring and plug gauges are designed to measure the functional size of an internal or external thread. Individual thread elements listed are measured with one or more specific instruments.

      
      

      See API 5B1 for additional inspection procedures.

      
      

   3. Application of the API Monogram

      
      

      If product (master gauges only) is manufactured at a facility licensed by API and it is intended to be supplied bearing the API Monogram, the requirements of Annex A apply.

      
      

   4. Other Applications

      
      

      By agreement between the purchaser and manufacturer, the supplemental requirements for Enhanced Leak Resistance LTC in API 5TRSR22 and Annex B apply.

      
      

      Information on the shipping of Master Gauges can be found in Annex C.

      
      

2. Normative References

The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any addenda or errata) applies.

API Recommended Practice 5A3, Thread Compounds for Casing, Tubing, Line Pipe, and Drill Stem Elements

API Specification 5L, Line Pipe Specifications, 6th Edition

1