Automotive Precision Seamless Alloy Steel Pipe (SCM415 / SCM420 / SCM430 / SCM435 / SCM440)

Material

This product is a precision seamless mechanical steel pipe manufactured from JIS SCM-series chromium–molybdenum (Cr-Mo) alloy steels. These steels are widely used for automotive and high-load mechanical parts because they combine high strength, good hardenability, fatigue resistance, and stable machining performance. Chemical composition requirements for SCM415/420/430/435/440 are defined in JIS G4053.

Specifications

• Product type: Precision mechanical seamless steel pipe / tube (hot-finished and/or cold-finished)

• Typical OD range: 6–323.8 mm (0.25"–12 3/4")

• Typical wall thickness: 1–50 mm (as required by design)

• Length: 3–12 m random; fixed length on request

• Manufacturing process: hot piercing → hot rolling → cold drawing/cold finishing (optional) → heat treatment (optional) → straightening → NDT/inspection

• Supply condition (optional): Annealed / Normalized / Stress-relieved / Quenched & tempered (per requirement)

Key Features

• Seamless structure for reliable pressure and fatigue performance

• Excellent heat-treat response (carburizing / quenching & tempering / induction hardening depending on grade)

• High strength-to-weight ratio for lightweight automotive design

• Good machinability for precision turning, drilling, honing, and threading

• Stable quality suitable for mass-production components

Our Advantages 

1. “Can you hold tight tolerances for automated assembly?”
   We offer cold-finished options with controlled OD/ID consistency, straightness, and surface quality, enabling stable fit-up for bushings, shafts, sleeves, and welded sub-assemblies.

2. “Can you deliver the exact heat-treatment condition I need?”
   We can supply multiple delivery conditions commonly used for mechanical tubes (e.g., hot-finished/cold-finished and normalized/annealed/stress-relieved), and align the condition to your target machining or performance requirements.

3. “How do you ensure compliance and traceability for automotive programs?”
   We provide heat/lot traceability, inspection documentation (e.g., chemical analysis, dimensional reports), and optional NDT (UT/ET) to support consistent qualification and repeatable supply.

Chemical Composition 

Mechanical Properties 

Standards (Typical Options, Brief)

• ASTM: ASTM A519/A519M (Seamless carbon & alloy steel mechanical tubing; hot-finished and cold-finished)

• EN: EN 10297-1 (Seamless circular tubes for mechanical and general engineering purposes); EN 10083 / EN 10084 (typical related steel families for Q&T / case-hardening)

• GOST: GOST 4543 (Alloy structural steels)

• JIS: JIS G4053 (Low alloy steels for machine structural use); JIS mechanical-tube standards can be applied per project requirement

• GB: GB/T 3639 (Cold drawn/honed precision seamless steel tubes); GB/T 3077 (Alloy structural steels)

Application Areas

Primary sectors: Automotive, construction machinery, industrial equipment, hydraulic/mechanical systems, high-strength shafts and sleeves.

Typical automotive usage (examples):

• Transmission & drivetrain: drive shafts, axle sleeves, spline sleeves

• Steering & chassis: steering shafts, torsion bars, stabilizer components

• Powertrain & structural parts: high-strength bushings, pins, precision sleeves

• General machining parts: spacers, collars, threaded mechanical components

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.