Precision seamless steel pipe tolerance accuracy

Dimensional tolerance
Dimensional tolerance refers to the difference between the actual size and the theoretical size of the inner and outer diameter of the steel pipe. The dimensional tolerance accuracy of precision seamless steel pipes is usually higher, and the following are some common tolerance ranges:

Ordinary precision seamless steel pipe: the outer diameter tolerance is usually ±0.05mm, which is the basic tolerance requirement in precision steel pipe manufacturing. The inside diameter tolerance will also be controlled within a similar range to the outside diameter tolerance.
High-precision seamless steel pipe: For occasions requiring higher precision requirements, such as aerospace, medical equipment and other fields, the outer diameter tolerance can reach ±0.025mm or even smaller. The inside diameter tolerance is also controlled within the corresponding high precision range.
Special precision and special precision steel pipe: in special applications, such as precision instruments, electronic equipment and other fields, the outer diameter tolerance can be controlled within ±0.01mm or even ±0.005mm. Bore tolerances are also subject to specific accuracy requirements.
It should be noted that the tolerance range of the outside diameter may also increase with the increase of the outside diameter. For example, when the outer diameter is between 6 and 10mm, the tolerance may be ±0.20mm; When the outer diameter is between 30 and 50mm, the tolerance may increase to ±0.40mm. However, this law is not absolute, and the specific tolerance range needs to be determined according to the actual demand and production process.

2. Shape tolerance
Shape tolerance refers to the deviation between the shape of the inner and outer surfaces of the steel pipe (such as roundness, straightness, etc.) and the ideal shape. For precision seamless steel pipes, shape tolerance is equally important, because it directly affects the stability and reliability of the steel pipe.

Roundness tolerance: refers to the deviation between the actual shape of the inner and outer surfaces of the steel pipe and the ideal circle. For high-quality seamless precision pipes, the roundness tolerance is usually small to ensure the stability and reliability of the steel pipe in the process of rotation, connection, etc.
Straightness tolerance: refers to the deviation between the actual shape of the inner and outer surfaces of the steel pipe and the ideal straight line. This tolerance is also crucial for the stability and reliability of the steel pipe in the direction of length.