420 is medium-carbon general martensitic stainless steel bright bar.

Higher carbon content than 410 enables hardness up to HRC48~58 after quenching, with superior wear resistance and compressive strength over 410, widely used for cutlery, valves and wear-resistant standard parts. Its basic corrosion resistance is slightly better than carbon steel, only resistant to dry atmosphere, fresh water and neutral weak acid, poor performance in brine, seawater and all chloride media.

Limitation: High carbon easily precipitates chromium carbide at grain boundaries when held at 400~600℃, causing severe intergranular corrosion after welding. Post-weld full quenching & tempering is mandatory for critical pressure & anti-corrosion components.

Full annealing at 750~850℃ softens material to HB ≤235 for easy turning. Moderate ductility only for simple bending & shallow stamping, severe cracking during deep drawing & cold heading. It cannot be strengthened by cold working, hardness improvement only achieved by quenching & tempering.

Chemical element content (%)

Specification：1.00~300.00mm

Application:It is mainly used to manufacture food cutlery, small mould inserts, wear-resistant fresh water valve spools, wear-resistant pins for drying equipment, load-bearing tool bars for low-temperature furnaces, wear-resistant hot air circulation valve bodies, medium-temperature chloride-free pump shafts, general wear-resistant stainless steel standard parts, dryer support bolts, small wear-resistant mechanical pins for civil use, etc.
Widely applied in kitchen cutlery industry, general small mould supporting parts, complete fresh water valve equipment, food drying production lines, industrial low-temperature heat treatment furnaces, petrochemical chloride-free dry heat units, civil hot air drying equipment, general small wear-resistant machinery fittings and other industries.

Core Advantages Over Competitors

1. High quality stability: Full closed-loop production with dual online spectral & metallographic inspection strictly control C, Cr, Ni key alloy elements. Controllable martensitic grains and evenly dispersed carbide precipitates ensure negligible batch fluctuation of low-temperature toughness, nitric acid resistance and creep strength for consistent mass production of aerospace and chemical high-pressure components.

2. Excellent surface quality: Dedicated high-precision cold drawing & centerless grinding lines produce bars free of peeling, scale, scratches and pits with mirror finish. Smooth surface reduces cyclic thermal oxidation stress concentration to greatly extend fatigue life of parts operating long-term at 500℃ under steam & acid service; secondary polishing is unnecessary for most precision machining.

3. Ultra-high dimensional accuracy: Precision cold rolling mills and automatic online dimension detectors narrow tolerance range with tiny single-bar error and strong batch uniformity. Unified part specifications during automatic mass production significantly raise finished yield and machining precision.

4. Rich product variety: According to market demand and customer's special requirements, customized products are provided to meet the use requirements under various complex working conditions, providing customers with more choices.

5. Perfect after-sales service: The perfect after-sales service system can respond to customer needs and feedback in a timely manner. For problems encountered by customers during use, technical support and solutions are provided to customers quickly.

We mainly engage in cold heading wire, bar, peeled bar, and profiled bar; our products cover 11 series and more than 300 grades, and we continue to develop a variety of professional steels. We can provide all-round solutions such as cold heading finishing line manufacturing and high-precision bright bar customization, and provide one-stop procurement services and package procurement solutions for global customers. The website displays some grades. If you don’t have the grade you need, please contact us by phone or email.