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420 Stainless Steel Round Bar

High-Hardness Stainless Steel Round Bar for Wear-Resistant Applications

420 Stainless Steel Round Bar is a martensitic stainless steel known for its high hardness, wear resistance, and good mechanical strength after heat treatment. It offers a practical balance of corrosion resistance and durability for demanding engineering applications.

Widely used in cutting tools, industrial components, valve parts, and mechanical equipment requiring enhanced hardness and abrasion resistance.

Product Features

Factory Direct High-Hardness 420 Stainless Steel Round Bar for Precision Machining & Shafts

420 stainless steel round bar (UNS S42000, EN 1.4021 / 1.4028, SUS420J1 / SUS420J2 martensitic stainless steel rod) is hot-rolled, cold-drawn, or precision centerless ground to deliver exceptionally high mechanical strength, outstanding wear resistance, moderate atmospheric corrosion endurance, and superior hardenability after heat treatment. Engineered specifically for pump shafts, valve stems, surgical instruments, plastic mold inserts, and industrial cutlery, high-quality 420 stainless steel round bar achieves hardness levels up to 48–54 HRC following oil quenching and tempering.

At XQJ Metal, we operate horizontal continuous casting equipment, hydraulic forging presses, multi-pass cold drawing machines, heat-treatment quenching furnaces, and high-precision centerless grinders to manufacture world-class 420 stainless steel round bar products conforming strictly to global engineering standards, including ASTM A276 (stainless steel bars and shapes), ASTM A479, EN 10088-3, and JIS G4303 specifications. We supply full diameter sizes ranging from 3mm to 300mm in round, square, and hexagonal bar profiles, available in annealed (soft), quenched and tempered (Q&T), and centerless ground surface conditions.

420 Stainless Steel Round Bar Technical Specifications & Material Matrix

Specification Parameter 420 Stainless Steel Round Bar Standard Values
Alloy Designation & Grade UNS S42000 / EN 1.4021 (X20Cr13) / EN 1.4028 (X30Cr13) / SUS420J1 / SUS420J2
Chemical Composition Chromium (Cr) 12.0% – 14.0%, Carbon (C) 0.15% – 0.36%, Manganese (Mn) ≤ 1.0%
Diameter Range & Profiles 3mm to 300mm (Precision small rods to large forged round bars)
Annealed Mechanical State Hardness ≤ 225 HB (Optimized for Swiss CNC lathe machining and milling)
Post Heat Treatment Hardness 48 HRC to 54 HRC (Oil Quenched at 980°C–1040°C + Low Temperature Tempered)
Precision Diameter Tolerances h7, h8, h9, h10, k9 (Centerless Precision Ground Tolerances)

420 Stainless Steel Round Bar vs. 304 Stainless Steel Round Bar: Engineering Selection Guide

Selecting between martensitic 420 stainless steel round bar and austenitic 304 stainless steel round bar depends on mechanical strength requirements, post-machining heat treatment, wear exposure, and operating environment:

  • Superior Post-Heat Treatment Hardness & Abrasion Resistance: Unlike non-hardenable 304 alloy, 420 stainless steel round bar contains higher carbon content, allowing it to achieve 50+ HRC hardness through heat treatment, preventing surface scoring on heavy-duty rotating shafts.
  • Excellent CNC Machinability in Soft Annealed Condition: In its soft annealed supply state, 420 stainless steel round bar cuts cleanly with short chip formation, making it highly efficient for high-speed automatic Swiss screw machining before hardening.
  • Moderate Corrosion Resistance for Industrial Media: While offering lower pitting resistance than 304 in marine chloride environments, 420 stainless steel round bar resists fresh water, mild acids, steam, crude oil, and air-borne oxidation effectively.

Precision Centerless Grinding, Heat Treatment & Custom Cutting for 420 Stainless Steel Round Bar

Pump manufacturers, valve fabricators, and precision machine shops rely on our custom processing capabilities for ready-to-machine 420 stainless steel round bar stock:

  • Centerless Precision Ground Tolerances (ISO h7 / h8 / h9): Precision ground round bars deliver exact diameter tolerances down to ±0.005mm with ultra-smooth mirror surface roughness (Ra ≤ 0.4µm), ideal for high-RPM Swiss CNC spindle feeding.
  • Vacuum Heat Treatment & Stress Relieving: Supplied in annealed condition or pre-hardened quenched & tempered (Q&T) state, thermal stress-relieved to prevent bar whipping or dimensional twisting during deep CNC turning.
  • Precision Saw Cutting & Chamfering: Cut-to-length custom blanks with smooth edge chamfering for automated machine feeding and reduced bar end scrap.

Key Industrial, Valve & Cutlery Applications of 420 Stainless Steel Round Bar

Our high-performance 420 stainless steel round bar products are specified across multiple heavy manufacturing sectors globally:

  • Pumps, Valves & Hydraulic Hardware: Centrifugal pump shafts, hydraulic cylinder rods, gate valve stems, compressor pistons, and turbine control pins made from 420 stainless steel round bar.
  • Cutlery, Surgical & Shearing Tools: Industrial cutting blades, surgical instruments, shears, meat grinder plates, and precision hand tools.
  • Plastic Molds & Wear Components: Plastic injection mold core pins, wear-resistant bushings, guide pillars, and extruding machine shafts.
  • Automotive & Aerospace Components: Gearbox shafts, fastener studs, brake disc pins, and heavy-duty mechanical collars.

Quality Assurance, Ultrasonic Flaw Testing & Export Packaging for 420 Stainless Steel Round Bar

To guarantee zero internal voids, uniform mechanical properties, and 100% metallurgical consistency, XQJ Metal enforces strict Quality Assurance protocols on every 420 stainless steel round bar shipment:

  • 100% Ultrasonic Flaw Detection (UT ASTM A388): Large diameter round bars (≥ 40mm) undergo full ultrasonic inspection to confirm zero internal cracks, shrinkage cavities, or inclusions.
  • Spectrometric & Hardness Audits: Direct-reading optical emission spectrum analysis, Rockwell/Brinell hardness testing, and tensile property audits backed by official Mill Test Certificates (MTC EN 10204 3.1).
  • Seaworthy Bundled Wooden Box Packaging: Bars are coated with anti-rust oil, wrapped in VCI protective moisture-proof film, plastic end-capped, steel-strapped, and crated in ISPM-15 fumigated wooden boxes for ocean freight.

Frequently Asked Questions (FAQ)

Q1: What hardness can 420 stainless steel round bar achieve after heat treatment?

A: When properly oil-quenched at 980°C–1040°C and tempered, 420 Stainless Steel Round Bar can achieve a surface and core hardness of 48 HRC to 54 HRC depending on carbon content grade (1.4021 vs. 1.4028).

Q2: Can XQJ Metal supply precision centerless ground 420 stainless steel round bars with h8 tolerance?

A: Yes, our precision centerless grinding mills can deliver round bars to tight h7, h8, or h9 diameter tolerances with mirror surface finish (Ra ≤ 0.4µm) tailored for automatic lathe turning.

To request current FOB/CIF price quotes, technical datasheets, or sample rods for 420 stainless steel round bar, Contact Our Technical Sales Team today.

Specifications

Item

Specification

Alloy

Temper

Thickness

Width

Surface Finish

Standard

Specifications

Item

Specification

Material Grade

420

Manufacturing Process

Hot Rolled / Cold Draw

Diameter Range

10–300 mm

Length

1000–6000 mm

Surface Finish

Bright / Black / Pickled

Standard

ASTM A276 / ASTM A479 / EN 10088

Processing Service

Cutting / Turning / CNC Machining

Application Areas

Our materials support a wide range of construction and infrastructure projects

Frequently Asked Questions

Any Question?

You can ask anything you want to know Feedback

420 stainless steel round bar contains a higher carbon content than 410, allowing it to achieve higher hardness after heat treatment. While both grades offer good corrosion resistance, 420 is commonly selected for applications requiring improved wear resistance and hardness.

Yes. 420 stainless steel round bar can be heat treated to achieve high hardness and improved wear resistance. The final mechanical properties depend on the specific heat treatment process and application requirements.

420 stainless steel round bar is widely used for knives, industrial blades, valve components, pump shafts, molds, and other parts requiring high hardness and good wear resistance. The appropriate heat treatment condition should be selected according to the intended application.

1 Why is 5083 aluminum coil used in marine environments?

It offers excellent resistance to seawater corrosion and maintains strength in humid and salt-rich conditions.

420 Stainless Steel Round Bar

No. Strength is achieved through strain hardening rather than heat treatment.

Yes. It provides excellent weldability for structural fabrication.

Yes, it is commonly applied in tanks and pressure equipment.

Yes. It provides higher strength compared with most non-heat-treated aluminum alloys.

Yes. Thickness, width and temper can be adjusted based on project demand.

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