25CrMo4 Seamless Cold Drawn Precision Steel Tube for Racing Applications
25CrMo4 Seamless Cold Drawn Precision Tube (EN 1.7218) for Racing & Motorsport
Material
This product is a seamless, cold-drawn precision steel tube made from 25CrMo4 (steel number 1.7218)—a chromium-molybdenum low-alloy, low-to-medium carbon steel designed for quenching and tempering to achieve an excellent strength-to-weight ratio, toughness, and fatigue resistance.
For racing and high-load mechanical parts, 25CrMo4 is widely used as an equivalent of SAE/AISI 4130 in many global supply chains.
Specifications
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Manufacturing route: hot-finished seamless mother tube → multi-pass cold drawing → sizing/straightening → cut to length → optional heat treatment.
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Outer diameter (OD): commonly 6–120 mm for motorsport structures; EN 10305-1 scope includes OD ≤ 380 mm.
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Wall thickness (WT): typically 0.8–12 mm (custom on request).
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Length: random or cut-to-length; defined length tolerances can be applied for exact lengths.
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Tolerance target: per EN 10305-1 / customer drawing; wall tolerance example ±10% or ±0.1 mm (whichever is greater) under certain ordering conditions.
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Surface: bright drawn / oiled; optional phosphated, pickled, or coated for storage and forming.
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Ends: plain, deburred, chamfered, bevelled; ID/OD cleaning available for precision assemblies.
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Delivery condition (examples): +C / +LC / +SR / +A / +N depending on forming vs. strength needs.
Main Features
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High strength-to-weight potential after Q&T (ideal for lightweight chassis and high-load parts).
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Excellent dimensional consistency from cold drawing for press-fit, CNC machining, and tight assemblies.
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Good weldability with correct practice, suitable for fabricated racing structures and brackets.
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Stable, clean bore and surface quality to reduce stress raisers and improve fatigue life in cyclic loading components.
Our Advantages
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“Will the tube meet tight tolerance and surface requirements for fabrication and machining?”
Yes. Precision tube standards emphasize defined tolerances and maximum surface roughness, and we manufacture with cold drawing + sizing and in-process gauging to support fit-critical parts (bushed joints, inserts, sleeving, etc.). -
“How do you ensure structural integrity and suitability for mechanical service?”
For mechanical tubing supply chains, buyers commonly specify standards such as ASTM A519 for seamless mechanical tubing (hot-finished or cold-finished) to ensure appropriate manufacturing control for mechanical applications.
We support: heat/lot traceability, chemical verification, tensile testing (as required), and optional NDT (eddy current / UT) aligned with precision-tube procurement practice. -
“Can I weld it for motorsport frames without cracking or distortion?”
Industry guidance for 4130-type tubing fabrication commonly highlights: clean prep, controlled heat input, and preheat/PWHT decisions based on thickness and restraint.
We can supply the tube in a fabrication-friendly condition (e.g., normalized/stress-relieved where specified) and provide welding notes to help your shop qualify a WPS for your wall thickness and sanctioning-body rules.
Chemical Composition
| Grade (Standard) | C | Si | Mn | P | S | Cr | Mo | Ni | Cu |
|---|---|---|---|---|---|---|---|---|---|
| 25CrMo4 (EN 10083-3) | 0.22–0.29 | ≤0.40 | 0.60–0.90 | ≤0.025 | ≤0.035 | 0.90–1.20 | 0.15–0.30 | — | — |
| 4130 (AMS / Bar/Tube limits) | 0.28–0.33 | 0.15–0.35 | 0.40–0.60 | ≤0.025 | ≤0.025 | 0.80–1.10 | 0.15–0.25 | ≤0.25 | 0.35 |
| SCM430 (JIS G 4053) | 0.28–0.33 | 0.15–0.35 | 0.60–0.90 | ≤0.030 | ≤0.030 | 0.90–1.20 | 0.15–0.30 | ≤0.25 | ≤0.30 |
| 30CrMo (GB/T 3077) | 0.26–0.33 | 0.17–0.37 | 0.40–0.70 | ≤0.030 | ≤0.030 | 0.80–1.10 | 0.15–0.25 | ≤0.30 | ≤0.30 |
| 30ХМ / 30KhM (GOST 4543) | 0.26–0.34 | 0.17–0.37 | 0.40–0.70 | ≤0.035 | ≤0.035 | 0.80–1.10 | 0.15–0.25 | ≤0.30 | ≤0.30 |
Mechanical Properties
| Grade | Example condition (reference) | Yield Strength (MPa) | Tensile Strength (MPa) | Elongation (%) | Hardness |
|---|---|---|---|---|---|
| 25CrMo4 (EN) | Q&T, small section | ≥700 | 900–1100 | ≥12 | — |
| 4130 (AMS tubing) | Tube AMS 6371, cold drawn | ≥483 | ≥655 | 12 | <25 (typ.) |
| SCM430 (JIS) | Q&T (example listed) | ≥785 | ≥930 | ≥12 | ≤229 HBW |
| 30CrMo (GB) | Q&T (example listed) | ≥785 | ≥930 | ≥12 | ≤229 HBW |
| 30ХМ / 30KhM (GOST) | Q&T (example listed) | ≥736 | ≥930 | ≥11 | — |
Standards (ASTM / EN / GOST / JIS / GB)
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EN: EN 10305-1 (seamless cold-drawn precision tubes; includes 25CrMo4 as an alloy option); EN 10083-3 (25CrMo4 material definition).
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ASTM: ASTM A519 (seamless carbon & alloy steel mechanical tubing, hot-finished or cold-finished).
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GOST: GOST 4543 (alloy construction steels; e.g., 30ХМ).
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JIS: JIS G 4053 (SCM series chemistry); JIS G 3441 (alloy steel tubes for machine purposes, includes SCM430TK).
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GB: GB/T 3077 (alloy structure steels; e.g., 30CrMo); GB/T 3639 (cold drawn precision seamless steel tubes, commonly used for “precision tube” procurement in China).
Application Areas
Typical industries: motorsport & racing, automotive performance, aerospace/defense structures, precision machinery, energy equipment.
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Racing / Motorsport: roll cage & chassis tubes, suspension links, subframe members, steering/sway components, reinforced sleeves/spacers.
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Automotive / Mechanical: shafts, axles, high-load pins, bush housings, machined sleeves, high-strength fastener sleeves.
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Aerospace-style fabrication: welded tubular structures where controlled properties and good weld practice are required.


Q: Are you trading company or manufacturer ?
A: manufacturer,also can do trading.
Q: How long is your delivery time?
A: Generally speaking,it is 10-15 days if the goods are in stock,or it is 30-40 days if the goods are not in stock,
it is according to quantity.
Q: Do you provide samples? is it free or extra ?
A: Yes, we could offer the sample for free charge but need pay the cost of freight.
Q: What is your terms of payment ?
A: Payment<=2000USD, 100% in advance. Payment>=2000USD, 30% T/T in advance ,balance before shippment.
If you have another question, pls feel free to contact with me.
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