Riveting pipe joint and riveting pipe joint connecting structure

Abstract

The invention provides a riveting pipe joint and a riveting pipe joint connecting structure, and the riveting pipe joint connecting structure comprises a connecting piece and a riveting pipe joint, a communicating part is arranged in the middle of the connecting piece, a head part and a riveting part are arranged at the two ends of the connecting piece respectively, internal threads are arranged on the inner wall, close to the head part, of the communicating part and the inner wall of the head part, and the outer diameter of the head part is larger than that of the communicating part; a plurality of flow guide holes are distributed in the communicating part in a circle in the circumferential direction at intervals, and the multiple flow guide holes form a hole group; the connecting piece is characterized in that the connecting cavity is internally provided with the internal threads, the connecting cavity is communicated with the multiple flow guide holes, the connecting cavity is communicated with the multiple flow guide holes, so that the connecting piece can be quickly connected, and the flow guide holes are communicated with the flow guide holes, so that the connecting piece can be quickly connected, and the connecting piece is convenient to use. And fluid can be kept to circulate in the connecting cavity after connection.

Description

Technical Field

[0001] The present application belongs to the technical field of connectors, and in particular relates to a riveted tube joint and a riveted tube joint connection structure. Background Art

[0002] In the prior art, the main line of the AI ​​server liquid cooling system is provided by a rectangular tube, and the pipe joint connected to the quick connector is achieved by welding. The welding efficiency is low and the quality is difficult to control.

[0003] To address the above problems, no effective solution has been proposed yet.

[0004] It should be noted that the above introduction to the technical background is only for the convenience of providing a clear and complete description of the technical solutions of the present invention and for the convenience of understanding by those skilled in the art. It cannot be considered that the above technical solutions are well known to those skilled in the art simply because these solutions are described in the background technology section of the present invention. Summary of the invention

[0005] The purpose of the present application is to provide a riveted tube joint and a riveted tube joint connection structure to solve the above problems.

[0006] The present application provides a riveted tube joint, comprising:

[0007] A connecting piece, wherein a connecting cavity is formed in the connecting piece;

[0008] The middle position of the connecting piece is set as a connecting part, and the two ends of the connecting piece are respectively set as a head and a riveted part, and the inner wall of the connecting part close to the head and the inner wall of the head are both provided with internal threads, and the outer diameter of the head is larger than the outer diameter of the connecting part;

[0009] The connecting portion is provided with a plurality of flow guide holes spaced apart along a circumferential circle, and the plurality of flow guide holes form a hole group; one or more layers of the hole group are spaced apart along a direction perpendicular to the circumferential direction of the connecting portion, and the plurality of flow guide holes are connected to the connecting cavity, so as to allow fluid to flow through the connecting portion of the connector.

[0010] Preferably, the head has a connecting surface on one side facing the connecting portion, and a sealing groove is formed on the connecting surface.

[0011] Preferably, a sealing ring is installed in the sealing groove or the sealing groove is filled with sealing glue.

[0012] Preferably, a first tooth portion is provided at the connection between the connecting portion and the head portion, and the first tooth portion is continuously distributed along the circumference of the connecting portion and is closed.

[0013] Preferably, the connecting cavity is configured as a through hole or a blind hole.

[0014] Preferably, a second tooth portion is provided at the connection between the riveted portion and the connecting portion, and the second tooth portion is continuously distributed along the circumference of the outer wall of the riveted portion and is closed.

[0015] Preferably, a connection portion between the riveted portion and the second tooth portion is recessed toward the direction of the connecting cavity to form a receiving groove.

[0016] A riveted tube joint connection structure, comprising the riveted tube joint, wherein the connecting portion is inserted into a rectangular tube through a connecting hole, the head portion contacts the outer wall of the rectangular tube, and the riveted portion is riveted to the wall of the rectangular tube away from the head portion; wherein a plurality of the guide holes are connected to the inner cavity of the rectangular tube.

[0017] Preferably, the head has a connecting surface on one side facing the connecting portion, and a sealing groove is formed on the connecting surface; a sealing ring is installed in the sealing groove or is filled with sealant for sealing the connection between the head and the rectangular tube.

[0018] Preferably, a first tooth portion is provided at the connection between the connecting portion and the head portion, the first tooth portion is continuously distributed and closed along the circumference of the connecting portion, and the first tooth portion is in contact with the outer wall of the rectangular tube and embedded in the outer wall material of the rectangular tube.

[0019] Preferably, the riveted portion is connected to the inner wall of the rectangular tube by riveting, and the connecting cavity is set as a through hole.

[0020] Preferably, the riveted portion passes through a side wall of the rectangular tube away from the head, and the riveted portion is connected to an outer wall of the rectangular tube by riveting, and the connecting cavity is configured as a blind hole.

[0021] Preferably, a second tooth portion is provided at the connection between the riveted portion and the connecting portion, the second tooth portion is continuously distributed and closed along the circumference of the outer wall of the riveted portion, and the second tooth portion is embedded in the material of the rectangular tube.

[0022] Preferably, a connection portion between the riveted portion and the second tooth portion is recessed toward the direction of the connecting cavity to form a receiving groove, and the receiving groove is used to accommodate the material of the rectangular tube.

[0023] Preferably, the connecting piece is made of plated carbon steel, stainless steel, aluminum alloy or copper alloy.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. The present invention provides an internal thread in the connection cavity, and the connection cavity is connected with a plurality of flow guide holes, so that the connector can not only be connected quickly, but also keep the fluid flowing in the connection cavity after the connection.

[0026] 2. The present invention provides a sealing groove for installing a sealing ring or filling a sealant, so that the connection of the head portion of the connector can be sealed, thereby improving the reliability of the connector installation.

[0027] 3. The present invention provides the first tooth portion and the second tooth portion, thereby significantly improving the anti-rotation capability of the connecting member after connection.

[0028] 4. The connection cavity of the present invention can be connected with the inner cavity of the rectangular tube through the guide hole, so that the fluid can flow in the connection cavity and the inner cavity of the rectangular tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0030] Figure 1 It is an overall structural diagram of a riveted tube joint and a connecting piece of a riveted tube joint connection structure provided in an embodiment of the present application.

[0031] Figure 2 A riveted tube joint and a riveted tube joint connection structure provided by an embodiment of the present application, wherein the connection cavity is set as a through hole structure;

[0032] Figure 3 A riveted tube joint and a riveted tube joint connection structure provided in an embodiment of the present application, wherein the connection cavity is set as a blind hole structure.

[0033] In the figure: 1, connecting piece; 11, connecting cavity; 12, connecting part; 121, guide hole; 122, first tooth part; 13, head; 131, connecting surface; 1311, sealing groove; 14, riveted part; 141, second tooth part; 142, containing groove; 2, rectangular tube. DETAILED DESCRIPTION

[0034] In order to enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of this application.

[0035] In the description of the present invention, it should be noted that the orientations or positional relationships indicated by the terms "upper", "middle", "lower", "inner", "outer", "front", "back", etc. are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. The terms "first", "second", and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. The following describes an implementation method of the present invention based on its overall structure.

[0036] Reference Figure 1 As shown, an embodiment of the present application provides a riveted tube joint, comprising:

[0037] A connecting member 1, wherein a connecting cavity 11 is formed in the connecting member 1;

[0038] The middle position of the connector 1 is set as a connecting portion 12, and the two ends of the connector 1 are respectively set as a head 13 and a riveted portion 14. The inner wall of the connecting portion 12 close to the head 13 and the inner wall of the head 13 are both provided with internal threads, and the outer diameter of the head 13 is larger than the outer diameter of the connecting portion 12;

[0039] A plurality of flow guide holes 121 are distributed at intervals along a circumferential circle on the connecting portion 12, and the plurality of flow guide holes 121 form a hole group; one or more layers of hole groups are distributed at intervals along a direction perpendicular to the circumferential direction of the connecting portion 12, and the plurality of flow guide holes 121 are connected to the connecting cavity 11, so as to allow fluid to flow through the connecting portion 12 of the connector 1.

[0040] In this embodiment, please refer to Figure 1 , those skilled in the art can arrange the connection member 1 to have a connection cavity 11 inside. Further, the connection member 1 is specifically provided with a connecting portion 12, a head portion 13 and a riveted portion 14. In the specific arrangement, the connecting portion 12 is arranged in the middle of the connection member 1, and the head portion 13 and the riveted portion 14 are arranged at both ends of the connecting portion 12.

[0041] In the setting of the connection cavity 11, those skilled in the art may set the inner wall of the connection cavity 11 to have an internal thread. The internal thread may be specifically set on the inner wall of the head 13 and the inner wall of the connecting portion 12 near the head 13. The internal thread set above allows the connector 1 to be quickly connected to an external part, thereby significantly improving the reliability of the connection of the connector 1. In other embodiments, the internal thread in the connection cavity 11 may be replaced by other structures for connection, such as interference connection, riveting, etc.

[0042] Furthermore, a person skilled in the art may set a plurality of guide holes 121 on the connecting portion 12. Specifically, in setting the guide holes 121, a plurality of guide holes 121 may be spaced apart along a circle in the circumferential direction, so as to form a hole group. In an optional embodiment, a person skilled in the art may set one or more layers of hole groups spaced apart in a direction perpendicular to the circumferential direction of the connecting portion 12.

[0043] With the above structure, those skilled in the art can arrange the multi-layer hole groups to be spaced apart along the circumference of the connecting cavity 11 on the connecting member 1, or arrange the multi-layer hole groups to be evenly spaced apart.

[0044] The plurality of flow guide holes 121 are connected to the connection cavity 11 , so that the connection cavity 11 can keep the fluid flowing after the connection of the connector 1 is made.

[0045] In summary, those skilled in the art arrange the connection cavity 11 with an internal thread, and the connection cavity 11 is connected with a plurality of flow guide holes 121 , so that the connector 1 can not only be connected quickly, but also keep the fluid flowing in the connection cavity 11 after the connection.

[0046] In an optional embodiment, the head 13 has a connecting surface 131 on one side facing the connecting portion 12 , and a sealing groove 1311 is formed on the connecting surface.

[0047] With the above structure, those skilled in the art can arrange the connection surface 131 on the head 13 to have a sealing groove 1311. More preferably, a sealing ring is installed or filled with sealant in the sealing groove 1311. The above structure can seal the head 13 when connected, thereby improving the reliability of the connection of the connector 1.

[0048] Specifically, in this embodiment, a person skilled in the art can install the sealing ring in the sealing groove 1311. It is understandable that the sealing groove 1311 is circumferentially continuous and closed along the connecting surface 131, and after the sealing ring is installed in the sealing groove, after the connecting member 1 is connected, the connecting surface 131 is sealed by the sealing ring.

[0049] In this embodiment, when a person skilled in the art provides the sealant, the sealant may be filled into the sealing groove 1311. After the sealant is filled, the sealant may seal the connection of the connection surface 131.

[0050] In summary, those skilled in the art set the sealing groove 1311 for installing a sealing ring or filling it with sealant, so as to seal the connection of the head 13 on the connector 1, thereby improving the reliability of the installation of the connector 1.

[0051] In an optional embodiment, a first tooth portion 122 is provided at the connection between the connecting portion 12 and the head portion 13, and the first tooth portion 122 is continuously distributed and closed along the circumference of the connecting portion 12. That is, the first tooth portion 122 is provided on the connecting portion 12, and the first tooth portion 122 is provided at the position where the connecting portion 12 and the head portion 13 are connected.

[0052] With the above structure, when the connector 1 is connected, the head 13 contacts other parts, and the first tooth portion 122 contacts the material of other parts and is squeezed to form a fitting structure.

[0053] According to the above-mentioned interlocking structure, the first tooth portion 122 can make the connecting member 1 have the ability to prevent rotation after the connection is completed, thereby further improving the connection reliability of the connecting member 1.

[0054] In the above structure, the connector 1 is provided with a connection cavity 11. It is understandable that the connection cavity 11 is opened from the head 13 and extends toward the riveted portion 14. In this embodiment, preferably, the connection cavity 11 is set as a through hole or a blind hole.

[0055] With the above structure, a person skilled in the art can set the connection cavity 11 as a through hole. In this embodiment, the rivet portion 14 can be set to be riveted with the external part, so as to complete the connection of the connector 1. In another embodiment, the connection cavity 11 is set as a blind hole, and the rivet portion 14 can be set to be riveted with the external part, so as to complete the connection of the connector 1.

[0056] In the above-mentioned embodiment, the riveted part 14 is connected. Preferably, a second tooth portion 141 is provided at the connection between the riveted part 14 and the connecting part, and the second tooth portion 141 is continuously distributed and closed along the circumference of the outer wall of the riveted part 14. The second tooth portion 141 is provided on the riveted part 14 so that it can be embedded in the material of the external part, thereby improving the ability of the riveted part 14 to prevent rotation after connection.

[0057] In summary, those skilled in the art arrange the first tooth portion 122 and the second tooth portion 141 , so as to significantly improve the anti-rotation capability of the connecting member 1 after connection.

[0058] Furthermore, in this embodiment, preferably, the connection portion between the riveted portion 14 and the second tooth portion 141 is recessed toward the direction of the connecting cavity 11 to form a receiving groove 142 .

[0059] With the above structure, the receiving groove 142 provided on the riveted portion 14 is located at the end of the connector 1 away from the head 13. During the connection process of the riveted portion 14, the material of the external part will be squeezed into the receiving groove, thereby preventing the connector 1 from falling out during the connection process.

[0060] The present specification also provides a riveted tube joint connection structure, including a riveted tube joint, wherein a connecting portion 12 is inserted into the rectangular tube 2 through a connecting hole, a head 13 is in contact with the outer wall of the rectangular tube 2, and a riveted portion 14 is riveted to the wall of the rectangular tube 2 away from the head 13; wherein a plurality of guide holes 121 are connected to the inner cavity of the rectangular tube 2.

[0061] In this embodiment, those skilled in the art pass the connector 1 through the rectangular tube 2, and an internal thread is provided in the connecting cavity 11 of the connector 1, so that the connector 1 can be connected with other parts.

[0062] Further, in the connected mechanism, the outer diameter of the head 13 is greater than the outer diameter of the connecting portion 12. The connecting member 1 is inserted into the inner cavity of the rectangular tube from the connecting hole on the rectangular tube 2. A plurality of flow guide holes 121 are provided on the connecting cavity 11 of the connecting member 1. According to the above embodiment, the plurality of flow guide holes 121 form a hole group; one or more layers of the hole group are spaced apart in a direction perpendicular to the circumferential direction of the connecting portion 12, and the plurality of flow guide holes 121 are connected to the connecting cavity 11.

[0063] By means of the above structure, the connecting cavity 11 can be connected with the inner cavity of the rectangular tube 2 through the flow guide hole 121 , so that the fluid can flow in the connecting cavity 11 and the inner cavity of the rectangular tube 2 .

[0064] It is worth noting that those skilled in the art set up multi-layer hole groups so that the area flowing through the hole group cross section is larger than the area of ​​the inner cavity of the rectangular tube 2 , so that the installation of the connector 1 will not interfere with the flow of the fluid in the rectangular tube 2 .

[0065] In the specific setting structure, preferably, the head 13 has a connecting surface 131 on the side facing the connecting portion, and a sealing groove 1311 is opened on the connecting surface 131; a sealing ring is installed in the sealing groove 1311 or filled with sealant to seal the connection between the head 13 and the rectangular tube 2.

[0066] With the above structure, the connection between the head 13 and the outer wall of the rectangular tube 2 can be sealed by installing a sealing ring in the sealing groove 1311 or filling it with sealant.

[0067] Specifically, the sealing strip is installed in the sealing groove 1311, and can contact the wall surface of the sealing groove 1311 and the outer wall of the rectangular tube 2, so as to achieve a sealing effect. When the sealant is filled, the sealant seals the connection between the connection surface 131 where the sealing groove 1311 is located and the outer wall of the rectangular tube 2.

[0068] In one embodiment, preferably, a first tooth portion 122 is provided at the connection between the connecting portion 12 and the head 13 , the first tooth portion 122 is continuously distributed and closed along the circumference of the connecting portion 12 , and the first tooth portion 122 is in contact with the outer wall of the rectangular tube and embedded in the outer wall material of the rectangular tube 2 .

[0069] With the above structure, when the connector 1 is connected, the head 13 contacts other parts, and the first tooth portion 122 contacts the material of the rectangular tube 2 and is squeezed to form a fitting structure.

[0070] The first tooth portion 122 forms an interlocking structure with the material of the outer wall of the rectangular tube 2 during the extrusion process, so that the connector 1 will not fail due to rotation after installation.

[0071] Specifically, when the connecting member 1 has a tendency to rotate, the edge of the first tooth portion 122 and the outer wall material of the rectangular tube 2 are pressed against each other, thereby preventing the first tooth portion 122 from rotating relative to the rectangular tube 2 .

[0072] In the setting of the riveted portion 14, preferably, the riveted portion 14 is riveted to the inner wall of the rectangular tube 2, and the connecting cavity 11 is set as a through hole. In this embodiment, the riveted portion 14 can be riveted to the wall surface of the rectangular tube 2 away from the head, so that the connection of the connector 1 can be completed.

[0073] In another embodiment, preferably, the rivet portion 14 is provided through the side wall of the rectangular tube 2 away from the head 13, and the rivet portion 14 is riveted to the outer wall of the rectangular tube 2, and the connection cavity 11 is provided as a blind hole. In this embodiment, the connection cavity 11 is provided as a blind hole, and the rivet portion 14 and the wall surface of the rectangular tube 2 away from the head can be provided as a flip riveted, thereby also completing the connection of the connector 1.

[0074] In the above-mentioned embodiments, those skilled in the art set the connecting cavity 11 as a through hole when the riveted portion 14 is a press-riveted structure, and set the connecting cavity 11 as a blind hole when the riveted portion 14 is a flip-riveted structure, so that the connecting cavity 11 can be isolated from the outside world during the process of connecting the riveted portion 14 to the rectangular tube in various ways.

[0075] In summary, by matching the connection mode of the riveted portion 14 with the opening mode of the connection cavity 11 , the connector 1 can be used for connection in various situations, thereby improving the convenience of using the connector 1 .

[0076] In the further arrangement of the riveted portion 14, preferably, a second tooth portion 141 is provided at the connection between the riveted portion 14 and the connecting portion 12, the second tooth portion 141 is continuously distributed and closed along the circumference of the outer wall of the riveted portion 14, and the second tooth portion 141 is embedded in the material of the rectangular tube 2. The second tooth portion 141 is arranged on the riveted portion 14 so that it can be embedded in the material of the rectangular tube 2, thereby improving the ability of the riveted portion 14 to prevent rotation after connection.

[0077] In another optional embodiment, the connection between the riveted portion 14 and the second tooth portion 141 is recessed toward the connection cavity 11 to form a receiving groove 142 , and the receiving groove 142 is used to accommodate the material of the rectangular tube 2 .

[0078] The receiving groove 142 provided on the riveted portion 14 is located at the end of the connector 1 away from the head 13. During the connection process of the riveted portion 14, the material of the rectangular tube 2 will be squeezed into the receiving groove 142, thereby preventing the connector 1 from falling out during the connection process.

[0079] In the process of manufacturing the connector 1, preferably, the connector 1 is made of carbon steel, stainless steel, aluminum alloy or copper alloy with a coating, so as to meet the strength requirements of the connector 1 when used in various situations.

[0080] Although different specific embodiments are mentioned in the content of this application, this application is not limited to the situations described in the industry standards or embodiments, etc. Some industry standards or slightly modified implementation plans based on the implementation of the custom methods or embodiments can also achieve the same, equivalent or similar, or predictable implementation effects after deformation of the above embodiments. The embodiments of data acquisition, processing, output, judgment methods, etc. after these modifications or deformations can still fall within the scope of the optional implementation plans of this application.

[0081] The embodiments describe the present application. A person skilled in the art will appreciate that there are many modifications and changes to the present application without departing from the spirit of the present application. It is hoped that the attached embodiments include these modifications and changes without departing from the present application.

Claims

1. A riveted tube joint, characterized in that: include: A connecting piece, wherein a connecting cavity is formed in the connecting piece; The middle position of the connecting piece is set as a connecting part, and the two ends of the connecting piece are respectively set as a head and a riveted part, and the inner wall of the connecting part close to the head and the inner wall of the head are both provided with internal threads, and the outer diameter of the head is larger than the outer diameter of the connecting part; The connecting portion is provided with a plurality of flow guide holes spaced apart along a circumferential circle, and the plurality of flow guide holes form a hole group; one or more layers of the hole group are spaced apart along a direction perpendicular to the circumferential direction of the connecting portion, and the plurality of flow guide holes are connected to the connecting cavity, so as to allow fluid to flow through the connecting portion of the connector.

2. The riveted pipe joint for rectangular pipes according to claim 1, characterized in that: The head has a connecting surface on one side facing the connecting portion, and a sealing groove is formed on the connecting surface.

3. The riveted tube joint according to claim 2, characterized in that: The sealing groove is installed with a sealing ring or filled with sealing glue.

4. The riveted tube joint according to claim 1, characterized in that: A first tooth portion is provided at the connection between the connecting portion and the head portion, and the first tooth portion is continuously distributed along the circumference of the connecting portion and is closed.

5. The riveted tube joint according to claim 1, characterized in that: The connecting cavity is configured as a through hole or a blind hole.

6. The riveted tube joint according to claim 1, characterized in that: A second tooth portion is provided at the connection between the riveted portion and the connecting portion, and the second tooth portion is continuously distributed along the circumference of the outer wall of the riveted portion and is closed.

7. The riveted tube joint according to claim 6, characterized in that: The connection portion between the riveting portion and the second tooth portion is recessed toward the direction of the connecting cavity to form a receiving groove.

8. A riveted tube joint connection structure, characterized in that It includes the riveted tube joint described in any one of claims 1 to 7 above, wherein the connecting portion is inserted into the rectangular tube through a connecting hole, the head is in contact with the outer wall of the rectangular tube, and the riveted portion is riveted to the wall of the rectangular tube away from the head; wherein a plurality of the guide holes are connected to the inner cavity of the rectangular tube.

9. The riveted tube joint connection structure according to claim 8, characterized in that: The head has a connection surface on one side facing the connecting portion, and a sealing groove is provided on the connection surface; a sealing ring is installed in the sealing groove or is filled with sealant for sealing the connection between the head and the rectangular tube.

10. The riveted tube joint connection structure according to claim 8, characterized in that: A first tooth portion is provided at the connection between the connecting portion and the head portion. The first tooth portion is continuously distributed and closed along the circumference of the connecting portion. The first tooth portion contacts the outer wall of the rectangular tube and is embedded in the outer wall material of the rectangular tube.

11. The riveted tube joint connection structure according to claim 8, characterized in that: The riveting portion is connected to the inner wall of the rectangular tube by riveting, and the connecting cavity is set as a through hole.

12. The riveted tube joint connection structure according to claim 8, characterized in that: The riveted portion passes through a side wall of the rectangular tube away from the head, and the riveted portion is connected to an outer wall of the rectangular tube by riveting, and the connecting cavity is configured as a blind hole.

13. The riveted tube joint connection structure according to claim 8, characterized in that: A second tooth portion is provided at the connection between the riveted portion and the connecting portion. The second tooth portion is continuously distributed and closed along the circumference of the outer wall of the riveted portion. The second tooth portion is embedded in the material of the rectangular tube.

14. The riveted tube joint connection structure according to claim 8, characterized in that: The connection between the riveting portion and the second tooth portion is recessed toward the direction of the connecting cavity to form a receiving groove, and the receiving groove is used to accommodate the material of the rectangular tube.

15. The riveted tube joint connection structure according to claim 8, characterized in that: The connecting piece is made of carbon steel, stainless steel, aluminum alloy or copper alloy with a coating.

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