Needle Tubing Stiffness Test

The needle tubing stiffness test plays a critical role in ensuring the performance and safety of medical devices, particularly hypodermic needles. This test determines the resistance of stainless steel tubing to bending when a standardized force is applied. For professionals in the medical device industry—especially those involved in quality assurance of syringes—understanding this test is essential for meeting regulatory standards and ensuring patient safety.

Syringetest.com offers high-precision solutions for conducting needle tubing stiffness tests, ensuring your products comply with global standards such as ISO 9626.

ISO 9626 and ISO 9626 Annex B

ISO 9626, titled Stainless steel needle tubing for the manufacture of medical devices — Requirements and test methods, sets out the physical and mechanical criteria for stainless steel tubing used in medical devices. Among its key components, ISO 9626 Annex B provides a detailed method for performing the needle tubing stiffness test, offering strict procedural requirements and equipment specifications.

Annex B outlines how to assess the stiffness by applying a specified force to the center of the tubing supported at both ends and measuring the resulting deflection. This process helps evaluate whether the tubing meets the mechanical strength needed to withstand real-world use without bending or failing.

Test Principle and Significance

The core principle of the needle tubing stiffness test is straightforward: a fixed downward force is applied to the center of the needle tubing, which is horizontally supported at both ends. The amount of deflection at the point of force application indicates the tubing’s stiffness.

Why is this important?

Product safety: Avoid bending or breakage during injection.
Manufacturing consistency: Ensure each batch meets the same mechanical standards.
Regulatory compliance: Meet ISO 9626 certification for global market entry.

Required Equipment for Needle Tubing Stiffness Test

To perform the test according to ISO 9626 Annex B, the following apparatus is necessary:

Capable of applying up to 60 N of force with an accuracy of ±0.1 N, featuring a blunt wedge-shaped plunger. The wedge must consist of two flat surfaces inclined at 60°, intersected by a cylindrical surface with a 1 mm radius.

Accurate to 0.01 mm, used to record how much the tubing bends under the applied force.

Syringetest.com provides customizable testing instruments that fully meet these technical requirements, helping labs and manufacturers implement standardized and repeatable testing processes.

Needle Tubing Stiffness Test Procedure

Place the tubing on the testing apparatus. Ensure:

The span matches values listed in ISO 9626 Table 2 for the given tubing size.
The plunger is centered.
The tubing is oriented perpendicular to both the plunger and support points.

Apply the downward force as specified for the tubing size, at a controlled rate of 1 mm/min to 10 mm/min.

Measure and record the deflection of the tubing at the center with an accuracy of ±0.01 mm.

A complete test report must include:

Tubing size and identification
Tubing type (RW, TW, ETW, UTW)
Measured deflection
Date of testing
Stainless steel alloy used

Syringetest.com’s automated stiffness testers simplify this process by integrating precision sensors and user-friendly interfaces to ensure repeatability and traceability of test results.

Why Choose Syringetest.com?

As a trusted provider of materials testing solutions, Syringetest.com delivers instruments that meet and exceed ISO standards. Our stiffness testers are engineered for:

High precision and reliability
User customization for special tubing sizes or alloy types
Automation options to boost testing efficiency
Data logging and traceability for audit readiness

We serve industries ranging from medical devices and pharmaceuticals to quality control labs. With a strong focus on innovation, we also support automation upgrades and custom test development.

The needle tubing stiffness test, when properly conducted under ISO 9626 Annex B, ensures that medical tubing maintains mechanical integrity during use. It’s not just about compliance—it’s about protecting patients and maintaining trust in medical products.

With professional-grade testing instruments from Syringetest.com, manufacturers can confidently ensure product quality, meet international standards, and streamline quality control processes.