What is a hypodermic tube?

A hypodermic needle tube, also known as a "hypodermic needle tube" or "medical grade needle tube", is a small diameter tubes used in medical applications, but can also be used in non-medical applications. The term "hypodermic" itself is defined as "under the skin," and traditionally, hypodermic tubes are made with sharp needles for injecting or withdrawing fluid or tissue into the human or animal body.

These types of products range from common single-use sharp needles used for vaccines and medicines, to uniquely functional biopsy needles or small-capacity specialty needles used to treat rare diseases. Needles using the hypotubes produced by Manners range from short, small diameter needles used in ophthalmology to large diameter needles that extend several feet long to aid in the insemination of cattle or horses.

Typically made of 304 or 316 stainless steel, hypodermic tubes is sized according to the Stubbs Iron Gauge due to its relative cost-effectiveness and wide acceptance in medical applications. The pin gauge system specifies standard outer diameters, inner diameters and their respective tolerances in a stepped format, where lower gauge numbers translate to larger nominal secondary conduit outside and inside diameters. The higher the gauge number, the smaller the OD/ID.

Hypodermic tubes are usually sold in rigid condition. Cold working during tubes stretching results in a rigid and strong tubes that does not easily bend or bend when force is applied longitudinally—a feature needed, for example, for sharp needle products to penetrate tissue. However, it can be fabricated at moderate or annealing (soft) temperatures if the application requires it.

The common governing specification for hypodermic tubes is ASTM A908 (needles) or ISO 9626 – both of which provide dimensions, chemical composition, and mechanical specifications for consideration by the buyer. The specifications detail the manufacturing process as "welding and drawing," which is the standard process for making hypodermic tubes because it is cost-effective and well-proven in the field. During the welding and drawing process, flat stainless steel strip is rolled into a tube, tungsten inert gas is welded along the weld, and then drawn over a floating plug/mandrel to size the tube to the final desired dimensions. The plugging process also integrates the weld zone into the rest of the tube, resulting in a properly pulled tube with a "seamless look" with a smooth outer diameter and improved inner diameter finish.

Suitable for a variety of medical and non-medical applications, versatile stainless steel hypodermic tubes available in any length or fabricated form is a proven material choice for existing products and a starting point for new projects in development.