Martensitic Stainless Steel Round Bars – Grades 410, 420, 430, 440C – High

• Complete martensitic stainless steel round bar series including 410, 420, 430, 440C grades for diversified hardness demands
• Adjustable high hardness & wear resistance via quenching + tempering heat treatment process
• Good mechanical strength and anti-rust property under dry atmospheric & weak corrosive environments
• High carbon grades (420 / 440C) deliver ultra-high hardness for cutting tools, bearing and wear parts
• Magnetic characteristic after heat treatment, low cost compared with nickel-bearing stainless alloys
• Custom hot rolled, hot forged and full CNC precision machining per customer CAD drawings
• Manufactured fully compliant with ASTM A276, ASTM A108 international bar standards
• Long service life for wear-resistant mechanical components with competitive raw material cost

This series martensitic stainless steel round bars cover 410, 420, 430, 440C grades, produced by hot rolling and hot forging process. Different carbon content leads to distinct hardness potential after quenching & tempering. Low-carbon 410 & 430 own good toughness, while medium-carbon 420 and high-carbon 440C achieve extreme surface hardness for heavy wear working conditions. All grades feature magnetic property, low alloy cost and stable dimensional accuracy after heat treatment, widely processed into shafts, cutlery, bearings, mold inserts and wear-resistant blanks for machinery, food hardware and tool industry.

Low carbon martensitic grade with basic corrosion resistance; good toughness after tempering; moderate hardness, ideal for general structural parts, valve components and pump shafts with light wear demand.

420 Stainless Steel
Medium carbon martensitic stainless steel; higher carbon content brings elevated hardening capacity after quenching; balanced rust resistance & hardness for cutlery, mold parts and medical instrument hardware.

430 Stainless Steel
Ferritic-martensitic transitional grade; lower carbon, excellent formability, good oxidation resistance at medium temperature, suitable decorative fittings and low-load structural bars.

440C Stainless Steel
Highest carbon martensitic stainless steel grade; maximum hardness after quenching, outstanding wear resistance; premium choice for bearings, cutting tools and high-wear precision mechanical parts.

• Martensitic Stainless Steel: 410,420,430,440A,440B,440C,416 free machining grade
• Austenitic Stainless Steel: 304,304L,316L,321,347,904L,254SMo
• Duplex Stainless Steel: 2205,2507,S32750,F51,F55
• PH Precipitation Hardening Steel:17-4PH,15-5PH,17-7PH
• Nickel Base Alloys: Monel400, Incoloy825/925, Inconel601/625/690, Hastelloy C4/C276
• Alloy & Carbon Steel:4140,4340,F22,F91,A105,A516 Gr70

1. Tunable High Hardness & Wear Resistance
Different carbon grades support customized quenching & tempering treatment; 440C can reach HRC58-62 ultra hardness for heavy wear working parts.

2. Cost-Effective Raw Material
No expensive nickel element added, much lower material cost than 304/316 austenitic stainless steel for dry environment applications.

3. Magnetic Feature & Stable Strength
All grades show obvious magnetism after heat treatment, good tensile strength for magnetic mechanical assembly components.

4. Easy Machining In Annealed State
Fully annealed delivery state owns soft matrix, convenient turning, milling, drilling before hardening heat treatment.

5. Moderate Atmospheric Corrosion Resistance
Enough anti-rust capacity for indoor, dry air and weak alkaline medium, suitable hardware and general machinery parts.

• 410: General valve shafts, pump parts, boiler fittings, low-load structural blanks
• 42: Kitchen cutlery, mold inserts, medical surgical hardware, bearing sleeves
• 430: Decorative fittings, household hardware, low-temperature furnace components
• 440C: Precision bearings, cutting tools, measuring gauges, high-wear mold cores
• General: Machinery shafts, fasteners, food processing equipment wear parts, hydraulic valve cores

We provide integrated hot rolling, hot forging and full precision machining services, and can produce finished components strictly according to customer CAD/PDF drawings:

• Custom fixed-length cutting, surface peeling, grinding & polishing
• CNC Turning, Milling, Planing, Drilling, Boring, Threading
• Custom quenching, tempering, full annealing heat treatment
• Gear cutting, special irregular profile forming & passivation treatment

We supply martensitic steel shafts, mold blanks, bearing cores, cutlery raw bars and fasteners for machinery, mold and hardware clients worldwide.

• UT Ultrasonic Testing to detect internal rolling & forging crack defects
• Tensile & hardness tester for mechanical performance inspection
• High-precision dimensional measuring instrument for tolerance control
• Spectrometer full chemical composition analysis per production batch
• Metallographic microscope grain microstructure observation

Mill Test Certificate EN 10204 3.1 can be provided together with shipment documents before delivery.

Packing
- Inner packaging: waterproof anti-rust polybag for moisture and scratch protection

- Outer packaging: reinforced fumigated wooden case / wooden pallet for long-distance sea transportation

- Custom special packaging available on customer request

Lead Time
Normally 10 – 45 days after receipt of advance payment. Exact delivery time depends on order quantity, bar diameter, length and customized heat treatment & machining requirements.