4130 Hollow Tubing
"Hollow tubing" usually comes up when someone wants to machine a ring, sleeve or bush and would prefer not to bore solid bar. In 4130 there are two hollow products to choose from: tube and hollow bar.
Tube vs. Bar in 4130 Alloy
4130 alloy is available in two primary product forms: hollow tube and solid bar (rod). When a buyer specifies '4130 hollow tubing', they are confirming the hollow product form — not the solid bar that is also used as machining stock. The hollow tube in 4130 is the CDS seamless tube governed by ASTM A519. Solid 4130 bar is governed by ASTM A29.
| Product Form | Standard | Primary Use |
|---|---|---|
| 4130 hollow tube (CDS) | ASTM A519 | Structural fabrication, aerospace, motorsport |
| 4130 solid bar / rod | ASTM A29 | Machining, turned parts, shafts |
| OD range (tube, verified) | 0.25 in – 5.0 in | Project source data |
| Wall range (tube, verified) | 0.035 in – 0.500 in | Project source data |
Choosing Hollow Stock for Machining
Tube is dimensioned by outside diameter and wall, with tolerances suited to use as-supplied. Hollow bar is a heavy-walled hollow intended purely as machining stock; it is sized by OD and ID together with the largest finished OD and smallest finished bore it is guaranteed to clean up to.
To choose, start from the finished part. Add machining allowance to the OD and subtract it from the bore, then look for the tube or hollow whose limits contain those figures. Thick-walled 4130 tube does the job for many parts, and the saving over solid bar grows with the bore size, since less metal is cut away and less time is spent drilling. State the finished dimensions in your enquiry so a suitable starting size can be offered. Related pages: heavy wall tubing and mechanical tubing.
Frequently Asked Questions
Is 4130 hollow tubing the same as 4130 bar with a hole bored through it?
No. 4130 CDS hollow tube is produced by the seamless tube manufacturing process (billet piercing and drawing) — not by boring a solid bar. Boring a solid bar to create a hollow section produces different grain flow and dimensional characteristics, and is not the standard tube product.
What is the difference between tube and hollow bar?
Tube is sized by OD and wall for use as supplied. Hollow bar is thick-walled machining stock sized to guarantee clean-up dimensions.
Why machine from hollow instead of solid 4130 bar?
Less material is removed, which saves machining time, tooling and scrap.
What dimensions should I give for machining stock?
The finished OD, bore and length of the part, so a tube that cleans up on both surfaces can be selected.
Is hollow stock supplied annealed?
It can be. State the condition that suits your machining and heat treatment.
Source 4130 Hollow Seamless Tubing
Specify OD, wall, standard, and condition for your hollow tube quotation.
- OD & Wall
- Standard (ASTM A519)
- Condition
- Footage
- MTC
- Delivery