Model specifications and dimensions of disposable injector needles.

Disposable syringe needle models and sizes include 1.6×38mm, needle tip length: 1.6×44, 1.2×38mm, needle tip length: 12.8×44, 1.05×38mm, needle tip length: 10.5×44, etc.

The thickness of the needle is expressed by number, generally No. 4.5, No. 5, No. 6, No. 7, etc. The needle size means how many millimeters the diameter of the needle is. Generally, children use size 4.5 or 5, and adults use size 7.
The inner diameter of No. 7 needle is 0.51mm, which represents purple. The inner diameter of No. 6.5 needle is 0.41mm, which represents blue. The inner diameter of No. 6 needle is 0.34mm, which represents orange. The inner diameter of No. 5 needle is 0.26mm, which represents red. The inner diameter of the needle is 0.21mm and the color is transparent. The needle is a hollow metal needle that can be freely attached and detached from the head end of the syringe. For the sake of safety and hygiene, disposable needles should be discarded after use and cannot be reused.

How to choose the right injection needle

1. Size

Choosing the right size injection needle is key. If the needle is too thick, it will hurt, and the injection site will be prone to bruising and other uncomfortable reactions; if the needle is too thin, it will be difficult to penetrate some viscous liquids and suspensions, and the injection speed of the liquid will be very slow. Therefore, when selecting injection needles, one should make a reasonable choice based on different drug characteristics and usage scenarios. Generally speaking, long and thin injection needles should be used to treat liquid medicines to allow the liquid to be injected more evenly into the muscles and subcutaneous tissue.

2. Materials

Currently, most injection needles on the market are made of stainless steel and plastic. And in actual operation, doctors and patients are most concerned about its safety and injury rate. Generally speaking, stainless steel injection needles have a high degree of strength and corrosion resistance, are more delicate, and cause less tissue damage during injection, so they are more suitable for injecting viscous macromolecule drugs. However, due to the low smoothness, the injection pain is more obvious.