4130 Chromoly for Needle Tubing
Needle tubing, also called hypodermic tubing, is extremely fine stainless steel tube made to gauge sizes. 4130 is not produced in this form and would not suit the purpose.
Is 4130 Suitable for Needle Tubing?
Needle tubing (hypodermic or capillary tubing) refers to extremely small diameter, thin-wall tubes used in medical, dispensing, and precision instrumentation. These are typically drawn from 304 or 316 stainless steel.
The standard verified size range for 4130 mechanical tubing stops at 0.250" OD. Tubing smaller than this is a specialist capillary product. Furthermore, 4130 is not biocompatible and is not used for medical needles. For industrial dispensing, stainless steel is the standard material.
What Needle Tubing Is
Hypodermic tube is drawn to outside diameters of a millimetre or two and below, with walls measured in hundredths of a millimetre. It is made from austenitic stainless steel because the tube must not corrode, must be cleanable and, in medical use, must be compatible with the body.
| Requirement | Material normally used |
|---|---|
| Medical and laboratory needles | Austenitic stainless steel such as 304 and 316 |
| Dispensing and instrument tips | Stainless steel hypodermic tube |
| Small structural or mechanical tube | 4130 from about 0.250" OD upwards |
If you are looking for the smallest 4130 sizes for mechanical use, such as fine linkages or small bushings, see small diameter tubing and capillary tubing. These are many times larger than needle tube.
Small Mechanical Parts Where 4130 Fits
Although it is not a needle material, 4130 is used for small, strong mechanical parts: pins, short shafts, locating sleeves, control rod ends and miniature structural members. These are made from the smallest regular tube sizes or from bar, and are often heat treated for wear resistance. If your requirement is a small, strong tube for a mechanism, describe the part and the loads and a suitable size can be suggested.
Frequently Asked Questions
Is needle tubing made from 4130?
No. It is made from austenitic stainless steel in gauge sizes.
What is the smallest 4130 tube available?
Regular supply starts at about 0.250" OD. Anything much smaller is outside the normal range for this alloy.
Why is stainless used for needle tubing?
It resists corrosion, can be sterilised and can be drawn to very fine sizes while keeping a clean bore.
Can 4130 be used for small precision sleeves?
Yes, in the smallest regular tube sizes or machined from bar, provided corrosion is not a concern.
How is needle tubing sized?
By gauge number, which defines the outside diameter, with the wall stated as regular, thin or extra thin.
Is there a standard for hypodermic tube?
Yes. Medical needle tubing is made to dedicated standards for stainless hypodermic tube.
Enquire for 4130 Mechanical Tubing
If your engineering assessment confirms 4130 mechanical tubing is suitable for your application, provide your OD and wall requirements.
- OD & Wall
- Standard (ASTM A519)
- Application description
- MTC requirement