4130 Cold Drawn Seamless Tubing
Cold drawn seamless, abbreviated CDS, is the full name of the most common 4130 tube product. "Seamless" describes how the hollow was made and "cold drawn" describes how it was brought to size.
ASTM A519 — The Governing Standard
In North America, 4130 Cold Drawn Seamless tubing is governed by ASTM A519 (Standard Specification for Seamless Carbon and Alloy Steel Mechanical Tubing). The standard covers both CDS and HFS forms, specifying chemical composition, dimensional tolerances, permissible variations, and mechanical property requirements (where applicable). Grade 4130 is listed explicitly in ASTM A519.
For aerospace applications, AMS-T-6736 (Aircraft Structural Tubing, Chromium-Molybdenum Steel) governs and mandates the normalized condition alongside the seamless form.
Dimensional Tolerances
ASTM A519 specifies tolerances for CDS 4130 tubing based on OD and wall. Buyers should consult the current version of the standard for the applicable tolerance class for their specific dimension. Key points:
- OD tolerance is a percentage of nominal OD for most size ranges.
- Wall thickness tolerance under ASTM A519 CDS is typically expressed as a percentage overage/underage.
- Tolerances tighten with smaller OD; looser tolerances apply to larger diameters.
- For dimensions requiring tolerances tighter than standard, a precision-drawn specification is required.
| Parameter | Specification Detail |
|---|---|
| Product form | Cold Drawn Seamless (CDS) |
| Grade | 4130 (AISI/SAE) |
| Primary standard | ASTM A519 |
| Aerospace standard | AMS-T-6736 |
| OD range (verified) | 0.25 in – 5.0 in |
| Wall range (verified) | 0.035 in – 0.500 in |
| Condition options | As-drawn, Normalized, Annealed, Stress-relieved |
| Documentation | EN 10204 3.1 MTC available |
CDS on Orders and Certificates
You will see the product written several ways: CDS, SMLS CD, or seamless cold drawn. They mean the same thing. On a mill test certificate the process appears alongside the standard and the delivery condition, for example seamless, cold drawn, normalized.
A short checklist for buying CDS 4130:
- Name the standard, normally ASTM A519 Grade 4130.
- Give OD and wall as decimals, and say which dimensions are to be controlled.
- State the delivery condition.
- Give length: random, or cut to a list.
- State the certificate required.
- Mention bending, machining or any special use.
Do not confuse CDS with DOM. DOM is a welded tube drawn over a mandrel and is normally a carbon steel product; the difference is set out on 4130 vs DOM tubing. The drawing process itself is described under 4130 cold drawn tubing.
Frequently Asked Questions
What is the difference between 4130 CDS and 4130 precision tubing?
Standard CDS 4130 per ASTM A519 is manufactured to standard dimensional tolerances. 'Precision tubing' implies tighter tolerances than standard, typically requiring additional drawing passes or a precision-drawn specification. Precision tubing should be specified with the required OD and wall tolerances, not just the 'precision' label.
Is AMS-T-6736 CDS 4130 available in the same OD range as standard ASTM A519?
AMS-T-6736 covers a defined range of sizes for aircraft structural applications. The size range may differ from the full ASTM A519 range. Verify availability for your specific dimension with the supplier at the enquiry stage.
What does CDS stand for?
Cold drawn seamless: a seamless tube finished to size by cold drawing.
Is CDS the same as DOM?
No. CDS starts as a seamless hollow. DOM starts as a welded tube that is then drawn over a mandrel.
Source 4130 CDS Tubing
Provide your ASTM A519 or AMS-T-6736 requirement, OD, wall, condition, and MTC requirement for a quotation.
- Standard (ASTM A519 or AMS-T-6736)
- OD and Wall
- Condition (As-drawn, Normalized, Annealed)
- Footage / Tonnage
- EN 10204 3.1 MTC requirement
- Delivery Location