GB/T 18457-2024 Stainless steel needle tubing for manufacture of medical devices - Requirements and test methods
1 Scope
This standard specifies the requirements of steel needle tubing (hereafter referred to as tubing) of designated metric sizes 0.18mm (34G) to 3.4mm (10G), and describe the test method.
This standard applies to rigid stainless steel needle tubing suitable for use in the manufacture of hypodermic needles and other medical devices for human use.
It does not apply to flexible stainless steel tubing because the mechanical properties differ from those specified for rigid tubing in this standard. However, manufacturers and purchasers of flexible tubing are encouraged to adopt the dimensional specifications given in this standard.
Note: Additional performance testing on the tube aspect may be required when the component is incorporated in the ready-to-use device.
2 Normative references
The following documents contain requirements which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 6682 Water for analytical laboratory use - Specification and test methods (GB/T 6682-2008, ISO 3696: 1987, MOD)
ISO 15510:2014 Stainless steels - Chemical composition
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
designated metric size
outer diameter of the tubing as defined in Table 1
Note: It is expressed in millimetres.
3.2
Gauge
legacy size designation
Note: A particular gauge size corresponds to a designated metric size defining limits for outer diameters.
3.3
wall thickness
material thickness between the inner and outer diameter of the tube
Note: It is expressed as RW=Regular Wall, TW=Thin Wall, ETW= Extra Thin Wall, and UTW=Ultra Thin Wall as designated in Table 1.
4 Materials
Tubing shall be made of austenite stainless steels listed in ISO 15510:2014, such as X2CrNi18-9, X5CrNi18-10, X6CrNiNb18-10, X5CrNiMo17-12-2, X6CrNiMoTi17-12-2 and X6CrNiMoNb17-12-2, or equivalent. Annex A provides comparison of stainless steel designations and chemical compositions.
5 Requirements and test methods
5.1 General
For the selection of tubing for a specific application and intended use, a risk based approach shall be applied.
5.2 Surface finish and visual appearance
When examined by normal or corrected vision, the outside surface of the tubing shall be smooth and free from defects, and the needle tube shall appear straight and of regular roundness.
Surface finish specifications may be different based on the final function of the medical device; in such cases, the medical device manufacturer should prepare specific specifications for surface finishing.
5.3 Cleanliness
When examined by normal or corrected vision, the surfaces of the tubing shall be free from metal soil and processing agents.
Cleanliness specifications may be different based on the final function of the medical device; in such cases, the medical device manufacturer should prepare specific specifications for cleanliness.
5.4 Limits for acidity and alkalinity
The extract for testing shall be prepared according to Annex B and determined with a laboratory pH meter, and the difference between the pH value of the extract and the control fluid shall be less than or equal to 1.0.
5.5 Size designation
Tubing size shall be designated by the nominal outer diameter, expressed in millimetres (i.e. the designated metric size), corresponding gauge size (e.g. G31 or 31G), and by wall thickness.
Example: 0.25 mm (31G) ETW.
5.6 Dimensions
The dimensions of tubing shall be as given in Table 1.
Table 1 Dimensions of tubing
Foreword I
1 Scope
2 Normative references
3 Terms and definitions
4 Materials
5 Requirements and test methods
5.1 General
5.2 Surface finish and visual appearance
5.3 Cleanliness
5.4 Limits for acidity and alkalinity
5.5 Size designation
5.6 Dimensions
5.7 Stiffness
5.8 Resistance to breakage
5.9 Resistance to corrosion
Annex A (Informative) Designation of stainless steel
Annex B (Nominative) Methods for preparation of extracts
B.1 Principle
B.2 Apparatus and reagents
B.3 Procedure
Annex C (Nominative) Test method for stiffness of tubing
C.1 Principle
C.2 Apparatus
C.3 Procedure
C.4 Test report
Annex D (Normative) Test method for resistance of tubing to breakage
D.1 Principle
D.2 Apparatus
D.3 Procedure
D.4 Test report
Annex E (Normative) Test method for resistance to corrosion
E.1 Principle
E.2 Reagents and apparatus
E.3 Procedure
E.4 Test report
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