阅读说明：本技术 一种用于螺纹接头上螺纹齿宽的检验量规及其检验方法 (Inspection gauge for thread tooth width on threaded joint and inspection method thereof ) 是由 詹先觉 张忠铧 于 2020-05-29 设计创作，主要内容包括：本发明公开了一种用于螺纹接头上螺纹齿宽的检验量规及其检验方法,包括量规本体；所述量规本体的顶部型面设置为曲面；所述顶部型面长度向的两端部垂下分别连有承载面和导向面,所述承载面和所述导向面设置为平面,且与所述量规本体的垂线之间形成夹角；所述承载面和所述导向面的底边均连有水平向的第一型面,所述第一型面设置为曲面或平面；所述第一型面的外侧边垂下分别连有第二型面,所述第二型面设置为平面；从而使得所述量规本体构成凸字形。本发明为了精确且方便地测量螺纹齿宽值,以保证加工的一致性。宽值,以保证加工的一致性。(The invention discloses an inspection gauge for the tooth width of a thread on a threaded joint and an inspection method thereof, wherein the inspection gauge comprises a gauge body; the top profile of the gauge body is set to be a curved surface; the two end parts of the top profile in the length direction are respectively connected with a bearing surface and a guide surface in a hanging mode, the bearing surface and the guide surface are arranged to be planes, and an included angle is formed between the bearing surface and the perpendicular line of the gauge body; the bottom edges of the bearing surface and the guide surface are both connected with a first horizontal molded surface which is a curved surface or a plane; the outer side edges of the first molded surfaces are hung down and respectively connected with second molded surfaces which are arranged to be planes; so that the gauge body forms a convex shape. The invention aims to accurately and conveniently measure the width value of the thread tooth so as to ensure the processing consistency. Wide value to ensure processing consistency.)

1. An inspection gauge for the width of a thread on a threaded joint, characterized in that: comprises a gauge body;

the top profile of the gauge body is set to be a curved surface;

the two end parts of the top profile in the length direction are respectively connected with a bearing surface and a guide surface in a hanging mode, the bearing surface and the guide surface are arranged to be planes, and an included angle is formed between the bearing surface and the perpendicular line of the gauge body;

the bottom edges of the bearing surface and the guide surface are both connected with a first horizontal molded surface which is a curved surface or a plane;

the outer side edges of the first molded surfaces are hung down and respectively connected with second molded surfaces which are arranged to be planes;

so that the gauge body forms a convex shape.

2. An inspection gauge for the thread width on a threaded joint as claimed in claim 1, wherein: the length of the top profile is matched with the tooth width of the thread on the measured threaded joint.

3. An inspection gauge for the thread width on a threaded joint as claimed in claim 1, wherein: the radius of curvature of the top profile is greater than 0mm and less than 10mm greater than the radius of curvature of the threaded joint being tested at that location.

4. An inspection gauge for the thread width on a threaded joint as claimed in claim 1, wherein: the roughness Ra of the top molded surface is less than or equal to 0.8 mu m; the roughness Ra of the bearing surface and the guide surface is less than or equal to 0.8 mu m.

5. An inspection gauge for the thread width on a threaded joint as claimed in claim 1, wherein: an included angle formed between the bearing surface and the perpendicular line of the gauge body and an included angle formed between the guide surface and the perpendicular line of the gauge body are both negative angles.

6. An inspection gauge for the thread width on a threaded joint as claimed in claim 1, wherein: the radius of curvature of the first profile is the radius of curvature of the top profile + the vertical height between the top profile and the first profile.

7. An inspection gauge for the thread width on a threaded joint as claimed in claim 1, wherein: the joint between the top molded surface and the bearing surface and the guide surface is provided with a fillet or a chamfer angle, and the fillet is 0.1mm to 2mm and is larger than the fillet at the corresponding position of the joint;

the bearing surface with the spigot surface with the junction between the first profile sets up to fillet or chamfer, the fillet is 0.1mm to 2mm, and is greater than the fillet that connects the corresponding position.

8. An inspection gauge for the width of a thread on a threaded joint according to any one of claims 1 to 7, wherein: the threaded connector comprises an external threaded connector and an internal threaded connector, and the gauge body comprises an external thread gauge and an internal thread gauge.

9. An inspection method based on an inspection gauge for the thread width on a threaded joint as claimed in claim 8, characterized in that: placing the external thread gauge in a tooth groove at the end part of the external thread joint, rotating and moving along the circumference of the external thread joint along the tooth groove to be far away from the end part of the external thread joint until the external thread gauge cannot move, recording the position of the external thread gauge on the external thread joint, measuring the spatial position of the position, if the measured spatial position of the position is within a design tolerance range, processing the thread tooth width on the external thread joint to meet the design requirement, and if the measured spatial position of the position is not within the design tolerance range, processing the thread tooth width on the external thread joint to not meet the design requirement;

and placing the internal thread gauge in a tooth socket at the end part of the internal thread joint, rotating and moving along the circumference of the internal thread joint along the tooth socket to be far away from the end part of the internal thread joint until the internal thread gauge cannot move, recording the position of the internal thread gauge on the internal thread joint, measuring the spatial position of the position, if the measured spatial position of the position is within a design tolerance range, processing the thread tooth width on the internal thread joint to meet the design requirement, and if the measured spatial position of the position is not within the design tolerance range, processing the thread tooth width on the internal thread joint to not meet the design requirement.

10. A method of verifying the thread width on a threaded joint as defined in claim 9, wherein: the spatial position for measuring the position is the axial distance from the position where the male screw gauge/the female screw gauge cannot move on the male screw joint/the female screw joint to the end of the male screw joint/the female screw joint, and the diameter of the male screw joint/the female screw joint at the position.

Technical Field

The invention relates to a tooth width inspection gauge in a joint thread machining process, in particular to an inspection gauge for the tooth width of a thread on a threaded joint and an inspection method thereof.

Background

In the field of drilling and developing of underground resources such as petroleum and natural gas, a drill rod is required to drill a stratum, a casing pipe is used for isolating the stratum from fluid in the pipe, and the oil pipe is used for conveying oil gas. Drill pipes, casing and tubing are often threaded, with steel pipes being connected one by one down to the ground to depths of several kilometers, each pipe being approximately 10 meters in length.

In practical application, the threaded connection joint needs to bear high tension and high internal pressure, and the joint often becomes a weak link of the whole tubular column.

Along with easy exploitation oil's exploitation is almost used up gradually, the oil exploitation degree of difficulty is increasingly big now, and along with new exploitation technology adoption such as acidizing fracturing, long horizontal well, rotatory running in, the tubular column service condition is more and more abominable moreover.

Under the consideration of technical, stratum or economic conditions, the lower part of a mined horizontal well has a long horizontal section, the pipe column is difficult to smoothly run into a target position only by the dead weight of the pipe column, and the whole pipe column is possibly required to be rotated by ground equipment to plug a pipe into a well hole, so that high torsional force must be borne between threaded connectors, and the pipe column can transmit high torque when the pipe column is rotationally run. With conventional threaded joints, the joint connection torque is mainly provided by the torque-stopping shoulders at the ends of the joints, which are limited in thickness due to the wall thickness of the pipes, and are susceptible to deformation failure when the torque is too high, and are directly exposed to the fluid in the pipes, and too high internal stress will also increase the stress corrosion failure of this part of the material.

As shown in FIG. 1, a fully engaged dovetail threaded connection was developed to improve the performance of the connection, which was satisfactory due to its unique thread design. The thread pitch of the thread guide surface is slightly smaller than that of the bearing surface, so that the tooth top width of the external thread is gradually increased from the thread end part, and the tooth top width of the internal thread is also gradually increased from the thread end part. The expansion of the thread of the male head 100 is similar to a spiral wedge with a dovetail-shaped section, the expansion of the tooth space of the female head 200 is also similar to a spiral wedge groove with a dovetail-shaped section, and the male head and the female head are in mutual screwing and matching processes and are in the shape of a wedge to be driven into a wedge groove, so that the inner thread tooth sides and the outer thread tooth sides are mutually matched and abutted during tightening. The flanks have a large surface area and can therefore carry high torques.

The size parameters of the internal and external threads of the joint are designed into matching values, and when the joint is screwed up, the tooth top, the tooth bottom and the tooth side of the threads just contact with each other. After the upper buckle is in place, the inner thread and the outer thread are in a full meshing state, and no gap exists between the threads, so that the joint can provide high-pressure inner and outer gas sealing capacity.

However, the joint is complicated to manufacture and small variations in manufacturing tolerances can cause differences in the fit of the inner and outer joints. The uncertainty of the actual machining size of the joint easily causes the difference of the axial buckling length after the joint is matched, so that the metal-to-metal sealing structure cannot be arranged at the end part of the joint, and the machining size of the thread, particularly the width value of the thread tooth, has to be strictly controlled.

The American standard API 5B adopts a ring plug gauge method to inspect a threaded joint, but the ring plug gauge is heavy and is suitable for inspecting oil pipes with small outer diameters, but is difficult to operate manually for casings with large outer diameters.

Disclosure of Invention

In view of the above-mentioned drawbacks in the prior art, an object of the present invention is to provide an inspection gauge for inspecting the thread width of a threaded joint and an inspection method thereof, which are used for accurately and conveniently measuring the thread width to ensure the machining consistency.

In order to achieve the purpose, the invention adopts the following technical scheme:

an inspection gauge for thread tooth width on a threaded joint, comprising a gauge body;

the top profile of the gauge body is set to be a curved surface;

the two end parts of the top profile in the length direction are respectively connected with a bearing surface and a guide surface in a hanging mode, the bearing surface and the guide surface are arranged to be planes, and an included angle is formed between the bearing surface and the perpendicular line of the gauge body;

the bottom edges of the bearing surface and the guide surface are both connected with a first horizontal molded surface which is a curved surface or a plane;

the outer side edges of the first molded surfaces are hung down and respectively connected with second molded surfaces which are arranged to be planes;

so that the gauge body forms a convex shape.

Preferably, the length of the top profile is matched with the tooth width of the thread on the measured threaded joint, and the machining tolerance precision reaches-0.05 mm to +0.05 mm.

Preferably, the radius of curvature of the top profile is 0mm to 10mm greater than the radius of curvature of the threaded joint being tested at that location. Preferably the radius of curvature is the better the closer to this location.

Preferably, the roughness Ra of the top molded surface is less than or equal to 0.8 mu m.

Preferably, an included angle formed between the bearing surface and a perpendicular line of the gauge body and an included angle formed between the guide surface and the perpendicular line of the gauge body are negative angles.

Preferably, the roughness Ra of the bearing surface and the guide surface is less than or equal to 0.8 mu m.

Preferably, the radius of curvature of the first profile is the radius of curvature of the top profile + the vertical height between the top profile and the first profile.

Preferably, the joint between the top profile and the bearing surface and the guide surface is a fillet or a chamfer angle, the fillet is 0.1mm to 2mm, and is greater than the fillet at the corresponding position of the joint.

Preferably, the joint between the bearing surface and the first molded surface and the guide surface is a fillet or a chamfer, and the fillet is 0.1mm to 2mm and is larger than the fillet at the corresponding position of the joint.

Preferably, the threaded connector comprises a male threaded connector and a female threaded connector, and the gauge body comprises a male threaded gauge and a female threaded gauge.

On the other hand, the inspection method for the thread tooth width on the threaded joint is characterized in that the external thread gauge is used for being arranged in a tooth groove of the end part of the external thread joint, the external thread gauge is rotated and moved along the circumference of the external thread joint along the tooth groove until the external thread gauge cannot move, the position of the external thread gauge on the external thread joint is recorded, the spatial position of the position is measured, if the measured spatial position of the position is within a design tolerance range, the thread tooth width machining on the external thread joint meets the design requirement, and if the measured spatial position of the position is not within the design tolerance range, the thread tooth width machining on the external thread joint does not meet the design requirement;

and placing the internal thread gauge into a tooth groove at the end part of the internal thread joint, rotating and moving along the circumference of the internal thread joint along the tooth groove to be far away from the end part of the internal thread joint until the internal thread gauge cannot move, recording the position of the internal thread gauge on the internal thread joint, measuring the spatial position of the position, if the measured spatial position of the position is within a design tolerance range, processing the thread tooth width on the internal thread joint to meet the design requirement, and if the measured spatial position of the position is not within the design tolerance range, processing the thread tooth width on the internal thread joint to not meet the design requirement.

Preferably, the spatial position for measuring the position is an axial distance from a position where the pin gauge/the box gauge cannot move on the pin/the box to an end of the pin/the box, and a diameter of the pin/the box at the position.

In the technical scheme, the inspection gauge and the inspection method for the tooth width of the thread on the threaded joint provided by the invention are extremely convenient and accurate to use and measure, and can quickly measure whether the tooth width of the set position of the processed threaded joint meets the requirement or not.

Drawings

FIG. 1 is a schematic representation of a prior art wedge-dovetail threaded joint;

FIG. 2 is a schematic representation of the topography of the surface of a prior art wedge dovetail threaded joint;

FIG. 3 is a perspective view of an external thread gauge in an embodiment of an inspection gauge of the present invention;

FIG. 4 is a schematic side view of an external thread gauge in an embodiment of an inspection gauge of the present invention;

FIG. 5 is a schematic view in the direction A-A of FIG. 4;

FIG. 6 is a schematic view of an externally threaded gauge embodiment of the inspection gauge of the present invention in use;

FIG. 7 is an enlarged schematic view of portion C of FIG. 6;

FIG. 8 is a schematic representation of the overall profile of an external thread gauge in an embodiment of an inspection gauge of the present invention;

FIG. 9 is a schematic perspective view of an internal thread gauge in an embodiment of an inspection gauge of the present invention;

FIG. 10 is a schematic side view of an internal thread gauge in an embodiment of an inspection gauge of the present invention;

FIG. 11 is a schematic view in the direction B-B of FIG. 10;

fig. 12 is a schematic view illustrating a use state of an internal thread gauge in an embodiment of the inspection gauge of the present invention;

FIG. 13 is an enlarged schematic view of portion D of FIG. 12;

fig. 14 is a schematic representation of the overall profile of an internal thread gauge in an embodiment of an inspection gauge of the present invention.

Detailed Description

The technical scheme of the invention is further explained by combining the drawings and the embodiment.

Referring to FIG. 2, in the conventional wedge-dovetail threaded joint having a thread pitch pS, a load face pL, and pS < pL, the inspection gauge of the present invention measures the thread width dimension to confirm that the threaded joint being machined meets the dimensional requirements.

Referring to fig. 3 to 14, the inspection gauge for the thread width of the threaded joint according to the present invention includes a male connector 101 and a female connector 201, and the inspection gauge is a gauge body including a male gauge 102 and a female gauge 202, which respectively correspond to the male connector 101 and the female connector 201. In addition to measuring the external diameter of the thread, the tooth width of the thread at a specified position is measured, and in order to prevent the gauge body from being worn in repeated use, the gauge body can be made of a material with higher hardness, such as tool steel, or the surface of the gauge body is coated with a layer of anti-wear material, and surface treatment such as nitriding, quenching and the like can be carried out, wherein the hardness is preferably more than 35 HRC.

As shown in fig. 3 to 8, the male thread gauge 102 used for measuring the male connector 101 is shaped like a single female thread, but the height H1 of the male thread gauge 102 is larger than that of the male connector 101.

The top profile 1 of the male thread gauge 102 is provided as a curved surface with a radius of curvature R5 that is 0mm to 10mm greater than the radius of curvature of the male threaded joint 102 being tested at that location, preferably the closer to that location the better. The radius of curvature of the top profile 1 is greater than or equal to the measured curvature of the pin 101 at that location, and can be matched to each other during measurement so as not to cause interference and measurement errors, and the roughness Ra of the top profile 1 is 0.8 μm or less than 0.8 μm.

The length direction of the top profile 1 (namely the tooth width length MPin-Tn of the external thread gauge 102) is respectively connected with a bearing surface 2 and a guide surface 3 which are hung down from two end parts, an included angle alpha 1 and an included angle beta 1 are respectively formed between the two end parts and the perpendicular line of the external thread gauge 102, the included angle alpha 1 and the included angle beta 1 are both negative angles, the negative angles refer to the included angle alpha 1 and the included angle beta 1 which are vertically positioned at the inner side of the bearing surface/guide surface of the external thread gauge and penetrate through the external thread gauge, and the angle values of the included angle alpha 1 and the included angle beta 1 are the same as the bearing surface and the guide surface of the tested external thread joint 101. The bearing and guide surfaces of the pin 101 are preferably at the same angle to the thread taper, i.e., angle β 1-angle α 1 is equal to the thread taper angle.

The tooth width length MPin-Tn of the external thread gauge 102 is processed into a design value with high precision, and the processing tolerance precision reaches-0.05 mm to +0.05 mm.

The bearing surface 2 and the guide surface 3 are both arranged as planes, the included angle between the bearing surface 2 and the guide surface 3 is preferably 0 degrees or the same as the included angle between the bearing surface and the guide surface of the tested male screw joint 101, and the roughness Ra of the bearing surface 2 and the roughness Ra of the guide surface 3 is 0.8 mu m or less than 0.8 mu m.

The bottom edges of the bearing surface 2 and the guide surface 3 are connected with first horizontal molded surfaces 4 and 5, and the first molded surfaces 4 and 5 are both curved surfaces or planes. If the curved surface is formed, the curvature radius R6 is greater than or equal to the curvature radius R5, and the curvature radius R6 is preferably R5+ H1, i.e., the curvature radius R5 of the top profile 1 + the tooth height H1 of the external thread gauge 102, with a tolerance range of-5 mm to +5 mm. ,

the outer sides of the first profiles 4 and 5 hang down and are respectively connected with a second profile 6, the second profile 6 is arranged to be a plane and is vertical to the horizontal axis of the tested male connector 101, and the roughness Ra of the second profile 6 is 0.8 mu m or less than 0.8 mu m.

The angle between the second profile 6 and the guide surface 3 is the same as the lead angle of the thread guide surface of the male connector 101 to be measured, which ensures that the second profile 6 is perpendicular to the horizontal axis of the male connector 101 to be measured when the guide surface 3 is engaged with the thread guide surface during measurement.

The connecting parts between the top molded surface 1 and the bearing surface 2 and the guide surface 3 are provided with fillets R2 and R3, the fillets R2 and R3 are 0.1mm to 2mm and are larger than the fillets at the corresponding positions of the joints. The fillet R2 of the external thread gauge 102 is greater than the fillet R2 'of the corresponding position of the measured external thread joint 101, and the fillet R3 of the external thread gauge 102 is greater than the fillet R3' of the corresponding position of the measured external thread joint 101, so that interference caused by fine foreign matters at the positions of the fillets R2 'and R3' of the corresponding position of the measured external thread joint 101 during measurement is avoided.

The joints between the bearing surface 2 and the guide surface 3 and the first profiles 4 and 5 are provided with fillets R1 and R4, the fillets R1 and R4 are 0.1mm to 2mm and are larger than the fillets at the corresponding positions of the joints.

As shown in fig. 9 to 14, the female screw gauge 202 for measuring the female screw 201 is shaped like a single male screw, but the height H2 of the female screw gauge 202 is larger than that of the female screw 201.

The top profile 7 of the female thread gauge 202 is provided as a curved surface, the radius of curvature R7 is smaller than the radius of curvature of the female thread joint 202 to be measured at the position by 0mm to 10mm, preferably, the radius of curvature closer to the position is better, the radius of curvature of the top profile 7 is smaller than or equal to the radius of curvature of the female thread joint 201 to be measured at the position, and the top profile 7 has a roughness Ra of 0.8 μm or less than 0.8 μm, which can be matched with each other during measurement so as not to cause interference and measurement errors.

The two end parts of the top profile 7 in the length direction (i.e. the tooth width length MBox-Tn of the internal thread gauge 202) are respectively connected with a bearing surface 8 and a guide surface 9, an included angle α 2 and an included angle β 2 are respectively formed between the two end parts and the perpendicular line of the internal thread gauge 202, the included angle α 2 and the included angle β 2 are both negative angles, and the angle values of the included angle α 2 and the included angle β 2 are the same as the bearing surface and the guide surface of the measured internal thread joint 201.

The tooth width length MBox-Tn of the internal thread gauge 202 is processed into a design value with high precision, and the processing tolerance precision reaches-0.05 mm to +0.05 mm.

The bearing surface 8 and the guide surface 9 are both arranged as planes, the included angle between the bearing surface 8 and the guide surface 9 is preferably 0 degrees, or the included angle is the same as the included angle between the bearing surface and the guide surface of the tested female adapter 201, and the roughness Ra between the bearing surface 8 and the guide surface 9 is 0.8 μm or less than 0.8 μm.

The bottom edges of the bearing surface 8 and the guide surface 9 are connected with horizontal first molded surfaces 10 and 11, and the first molded surfaces 10 and 11 are both curved surfaces or flat surfaces. In the case of a curved surface, the radius of curvature R8 is greater than or equal to the radius of curvature R7, preferably R7-H2, with a tolerance range of-5 mm to +5 mm.

The outer sides of the first profiles 10, 11 hang down and are respectively connected with a second profile 12, the second profile 12 is arranged to be a plane and is perpendicular to the horizontal axis of the measured female adapter 201, and the roughness Ra of the second profile 12 is 0.8 mu m or less than 0.8 mu m.

The angle between the second profile 12 and the guide surface 9 is the same as the lead angle of the thread guide surface of the female connection 201 under test, which ensures that the second profile 12 is perpendicular to the horizontal axis of the female connection 201 under test when the guide surface 9 is brought into engagement with the thread guide surface under test.

The junction between the top profile 7 and the bearing surface 8 and the guide surface 9 is provided with fillets R9 and R10, the fillets R9 and R10 are 0.1mm to 2mm and are larger than the fillets at the corresponding positions of the joints. The fillet R9 of the internal thread gauge 202 is larger than the fillet R9 'at the corresponding position of the measured internal thread joint 201, and the fillet R10 of the internal thread gauge 202 is larger than the fillet R10' at the corresponding position of the measured internal thread joint 201, so that interference caused by fine foreign matters at the positions of the fillets R9 'and R10' at the corresponding position of the measured internal thread joint 201 during measurement is avoided.

The joints between the bearing surface 8 and the guide surface 9 and the first profiles 10 and 11 are provided with fillets R11 and R12, the fillets R11 and R12 are 0.1mm to 2mm and are larger than the fillets at the corresponding positions of the joints.

As shown in fig. 3 to 8, when the male adapter 101 is actually measured, the male thread gauge 102 is disposed at the end of the male adapter 101, the male thread gauge 102 rotates and moves away from the end along the circumference of the thread tooth slot of the male adapter 101, and the male thread gauge 102 will fit with the thread of the male adapter 101 and cannot move as the tooth slot becomes smaller and smaller, and the tooth width MPin-Tn of the male thread gauge 102 is processed to a designed value, so that the tooth width at the position where the male adapter 101 fits can be determined as the tooth width of the male thread gauge 102. After the position is determined, the position is marked and the spatial position of the position, i.e., the axial distance Pin-deep and the diameter D1 from the end of the male connector 101, is measured by a depth gauge, micrometer or caliper gauge. During measurement, the guide surface 3 is attached to the thread guide surface, so that the second profile 6 can be perpendicular to the horizontal axis of the measured male connector 101, and the axial distance Pin-deep is more accurate. For convenience of measurement, the bottom of the tooth preceding the tooth in the fitting position may be selected when measuring diameter D1.

The tooth width length MPin-Tn of the external thread gauge 102 and the axial distance Pin-deep measured by the depth caliper satisfy a functional relation value, and the axial distance Pin-deep value can still meet the design requirement by grinding the second profile 6 under the condition that the tooth width length MPin-Tn has small size difference. If the measured axial distance Pin-deep value is within the design tolerance range, the thread tooth width machining of the male adapter 101 meets the design requirements; if the measured axial distance Pin-deep value is not within the design tolerance, the thread face width machining of the Pin joint 101 does not meet the design requirements.

The design external thread joint 101 measures the position tooth width and is MPin-Tn, because external screw thread gauge 102 is difficult to be processed into this size completely, perhaps the plug size has certain wearing and tearing after using a period of time, need examine and determine the size again, and it is MPin-Tn' to establish external screw thread gauge 102 size, then measures external screw thread joint 101 with this plug, then has:

as shown in fig. 9 to 14, when the female adapter 201 is actually measured, the female thread gauge 202 is placed at the end of the female adapter 201, the female thread gauge 202 rotates and moves away from the end along the circumference of the thread tooth socket of the female adapter 201, and the female thread gauge 202 fits with the thread of the female adapter 201 and cannot move as the tooth socket becomes smaller, and the tooth width MBox-Tn of the female thread gauge 202 is processed to the designed value, so that the tooth width at the position where the female adapter 201 fits can be determined as the tooth width of the female thread gauge 202. After the position is determined, the position is marked, and the spatial position of the position, namely the axial distance Box-deep and the diameter D2 of the position from the end of the female adapter 201, is measured by a depth gauge, a micrometer or a caliper gauge. During measurement, the guide surface 9 is attached to the thread guide surface, so that the second profile 12 can be perpendicular to the horizontal axis of the measured female adapter 201, and the axial distance Box-deep is more accurate. For convenience of measurement, the bottom of the tooth preceding the tooth in the fitting position may be selected when measuring diameter D2.

The internal thread gauge 202 has a tooth width length MBox-Tn that satisfies a functional relationship with the depth caliper measurement axial distance Box-deep, and the axial distance Box-deep still meets the design requirements by grinding the second profile 12 in the case of small differences in the tooth width length MBox-Tn. If the measured axial distance Box-deep value is within the design tolerance range, the thread tooth width machining of the female adapter 201 meets the design requirements; if the measured axial distance Box-deep value is not within the design tolerance, the thread face width machining of the female adapter 201 does not meet the design requirements.

The measuring position tooth width of the female adapter 201 is designed to be MBox-Tn, because the female thread gauge 202 is difficult to be completely processed into the size, or the size of the plug column is abraded to a certain extent after being used for a period of time, the size needs to be verified again, and if the size of the female thread gauge 202 is MBox-Tn', the plug column is used for measuring the female adapter 201, so that the following steps are provided:

for example, for a steel pipe with an outer diameter of 88.9 mm and a wall thickness of 6.45 mm, a dovetail-shaped wedge thread is processed at the end of the steel pipe, the male thread gauge 102 is placed in a tooth groove with a wider end of the male adapter 101, and the male thread gauge 102 is moved away from the end along the thread screwing direction until the male thread gauge 102 is embedded in the female thread and cannot be moved any more. Where the thread groove width is equal to the gauge width; then, a depth gauge is adopted to measure the linear distance from the end of the external thread gauge 102 to the end of the joint; if the linear distance is within the range indicated in the drawing, it is considered that the machining of the axial dimension of the thread of the male screw joint 101 satisfies the design requirement.

It should be understood by those skilled in the art that the above embodiments are only for illustrating the present invention and are not to be used as a limitation of the present invention, and that changes and modifications to the above described embodiments are within the scope of the claims of the present invention as long as they are within the spirit and scope of the present invention.