Is the internal thread of m68 by 2 a hole of 68

The inner bore diameter of M68X2 is 68-3+, and the tolerance is selected according to the accuracy.

Thread: A thread is a graphic composed of wire types, and there are many types of it. The most intuitive is the spiral line made on the surface of a cylinder or cone.

A protruding part of a shape with a specific cross-section. Threads are divided into cylindrical threads and tapered threads according to their parent shape; It is divided into external thread and internal thread according to its position in the matrix, and is divided into triangle according to its cross-sectional shape (tooth shape).

Threads, rectangular threads, trapezoidal threads.

Zigzag threads and other special shape threads, triangular threads are mainly used for connections, rectangular, trapezoidal and zigzag threads are mainly used for transmission; According to the direction of the spiral, it is divided into left-handed thread and right-handed thread, and the right-handed thread is generally used; According to the number of spiral wires, it is divided into single wire thread, double wire thread and multi-wire thread; The connection is mostly single-wire, and the transmission is double-wire or multi-wire; According to the size of the tooth, it can be divided into coarse thread and fine thread, etc., and can be divided into fastening thread and pipe thread according to different occasions and functions.

Transmission threads, special threads, etc.

The hole of the internal thread should be converted, if you are machined into a hole of 68, where does the thread go? Doesn't the external thread pass through it all at once as soon as it comes into contact with it? The inner bore diameter of M68X2 is 68-3+, and the tolerance is selected according to the accuracy.

M68 refers to the large diameter of the thread, not the diameter of the hole.

The bottom hole you ask? If it is a bottom hole, it is the thread large diameter - pitch = bottom hole.

If the pitch of thread M64 and M72 is 6 respectively, then the thread drilling is respectively.

The bottom hole of thread M64 6, d2 = mm, is processed by a drill with a diameter of mm.

The bottom hole of thread M72 6, d2 = mm, is processed by a drill with a diameter of mm.

Quote from: GB T 196-2003 Common Thread Basic Dimensions.

<> the path data in the table is what you call the bottom hole size.

According to the national standard JB Z228-85, the diameter of the threaded bottom hole of thread M64 and M72 is: 64 mm and 68 mm respectively.

2-M72X2-6H2 means that there are two places, M72X2 means that the rib specification is M72 fine tooth rib with a pitch of 2mm, and 6H is the rib accuracy grade.

Are the threaded hole diameters the same for M6-6H and M6*? What difference does it make if it's different?

Hello dear, glad to answer for you: Is the threaded hole diameter of M6-6H and M6* the same? What difference does it make if it's different?

A: The threaded hole diameter is the same. M6-6H, M6-6H, M6-6G, M6-6G, M6-6G indicate that the nominal diameter of the thread is 6mm. But the suffix at the back, 6h, 6g expresses the meaning of the internal thread, h and g are the meaning of the hole tolerance level 6h, 6g expresses the meaning of the external thread, h and g are the common difference of the shaft, I am a mechanical engineer to help others, quickly disturb the answer to myself.

The thread of M6 needs to be drilled in the bottom hole.

Generally speaking, the diameter of the gong bolt is multiplied by the diameter of the hole to be drilled.

Nominal diameters are also available.

Subtract the pitch. as the bottom hole size. For example, the pitch of M8 is, and the diameter of the drill bit can be selected when drilling the bottom hole to process the screw hole of M8. This is the theoretical size of the priming hole, which is used in practice to facilitate tapping.

The diameter of the bottom hole should be slightly larger than the theoretical size. In addition, different materials and drilling methods also have an impact on the selection of bottom hole size.

The bottom hole generally refers to the use of taps.

The diameter of the prefabricated hole before tapping the internal thread generally refers to the built-in round hole of the machined part, and the circular hole at the bottom or on the most surface is called the bottom hole.

If the diameter of the bottom hole is consistent with the diameter of the internal thread, the tap will be stuck when the material expands, and the tap is easy to break and disassemble; If it is too large, it will make the thread thread height not high enough and the lead will form a waste product. Threaded fits are required to have corresponding fit tolerances according to different international standards.

You can check the fitter's manual. If the bottom hole is a counterbore hole, it is also necessary to consider the impact of tapping and arrangement.

M6 Standard Pitch: Threaded Bottom Hole:

Fine pitch: Threaded bottom hole:

The standard pitch does not need to be marked with the Shen Hall out of the big filial piety brother, because of the rolling attack, the threaded bottom hole of M6 is:.

Hello dear! We'll be happy to answer for you. The size of the bottom hole of the M6 thread refers to the ordinary thread of the coarse tooth with a diameter of 6 mm, generally speaking, it is multiplied by the diameter of the bolt, and the hole diameter is to be drilled.

It is also possible to use the nominal diameter minus the pitch as the bottom hole size. In general, the diameter of the bottom hole should be smaller than the diameter of the thread, otherwise the material will jam the tap as it expands, causing it to break. The size of the punch hole will be different for different specifications of screws.

If you choose an M5 screw, the hole with a large multi-lease finger depends on the outer diameter and distance of the screw, which can be calculated according to the formula. By calculation, it can be found that in the case of M5 screws, the diameter of the hole is about 4 mm to mm.

M6 thread, extruded taps.

The bottom hole is generally left and right, and the bottom hole of the cutting tap is left and right.

The calculation methods involving different thread screws (tooth height ratio) are as follows:

1. Cutting taps:

Metric threads. s=d-%*p/

Inch threads. s=(d-%*where TPI refers to the number of teeth per inch) Second, extrusion tap:

Metric thread s=d-%*p

Imperial snail macro pattern s=(d-%*

Among them: % refers to the degree of thread screw (tooth height rate), if there are no special requirements, 75 is generally taken.

Summary. Millimetre.

Millimetre. M6 threaded bottom hole should be punched with respect. 1.

The screw is composed of five elements, namely tooth shape, nominal diameter, number of wires, pitch and direction of rotation, and there are many types of threads, the shape is cylindrical, conical, triangular, etc., each kind of thread has a different diameter, so the bottom hole is also different. Thread refers to the ordinary thread of a coarse tooth with a diameter of 6 mm. The spiral shape is a continuous convex part with a specific cross-section made on the surface of a cylinder or conical matrix.

3.Generally speaking, multiply the diameter of the bolt by the diameter of the hole. It is also possible to use the nominal diameter minus the pitch as the bottom hole size.

For example, the pitch of M8 is mm, and the diameter of the drill bit can be selected to be mm when drilling the bottom hole to process the screw hole of M8. This is the theoretical bottom hole size, in the actual operation, in order to facilitate tapping, the bottom hole diameter should be slightly larger than the theoretical size mm.

Extension: The bottom hole refers to the diameter of the prefabricated hole before the use of the tap to attack the internal thread, generally refers to the built-in round hole of the machined piece, and the bottom or most round hole is called the bottom hole. If the bottom bore diameter is the same as the diameter of the internal thread, the tap will get stuck and it will break easily; If it is too large, the cover will make the tooth shape not high enough, resulting in scrap.

According to different international standards, there needs to be corresponding fitting tolerances, which can be consulted in the fitter's manual. If it is a counterbore, the amount of chip evacuation should not be considered.

The maximum hole diameter before M6-6H thread tapping can not be exceeded, and a diameter of 5mm drill bit can be used, and the following will be sent to you the national standard "GB T 20330-2006 Twist drill diameter for drilling before tapping".