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Grade 420J1, martensitic stainless steel

420J1 Stainless Steel Coil and Sheet

A martensitic stainless steel with 0.16–0.25% carbon and 12–14% chromium, balancing hardness and corrosion resistance. Less carbon than 420J2, so better corrosion resistance and lower hardness; it hardens by heat treatment and suits mildly corrosive, wear-prone uses.
Tell us about your projectSee sizes
Forms
Coil, sheet
Thickness
0.15–3.0 mm
Width
1000 / 1219 / 1240 / 1500 mm
Standards
JIS G4303, G4304, G4305

Is Sanmei Metal the right supplier for you?

We supply stainless steel together with the processing and technical support that projects and products need.

A good fit if you

Need a specific grade, finish or size for a project, from samples or one coil to a few containers
Want it slit, cut to size or fabricated to your drawing
Need documents: a Mill Test Report with every order, SGS testing on request
Want help choosing the right grade and finish for your application
Build products or projects: equipment housings, architectural interiors, elevator and kitchen work

When buying direct from a mill may suit you better

You need standard grades in full-mill quantities and compare on price per tonne
Not sure which applies to you? Tell us about your order and we will give you our professional advice.
Tell us about your projectSee what we fabricate

Sizes we supply in 420J1.

Standard widths from stock, cut-to-length sheet, and custom slitting for strip-fed production lines.

420J1 coil

Width
1000, 1219, 1240, 1500 mm, or slit to your width
Thickness
0.15–3.0 mm
Coil weight
3–10 t

420J1 sheet

Width
1000, 1219, 1240, 1500 mm, or cut to size
Length
2000, 2438, 2500, 3000, 3048 mm
Thickness
0.3–3.0 mm
Every order ships with a Mill Test Report. Sample sheets and small batches are welcome. Standard mill finish: 2B finish.
Get a quote for 420J1Send a cut list or drawing

What 420J1 is, and where it is used.

A magnetic, hardenable steel for blades, tools and mechanical parts.

General properties

Carbon 0.16–0.25% and chromium 12.0–14.0%, with smaller amounts of other elements. Magnetic, and hardenable by heat treatment, to a lower hardness than 420J2.

Applications

Food preparation equipment, kitchen knife blades, industrial machinery blades, mechanical parts, surgical instruments, and decorative uses where standard corrosion resistance is enough.

Standards

JIS G4303 for bars, JIS G4304 for hot-rolled plate, sheet and strip, and JIS G4305 for cold-rolled plate, sheet and strip.
Tell us what the part is, where it will be used and roughly how many. We confirm the grade and finish before you order.
Tell us your application

Corrosion and heat resistance.

Better corrosion resistance than 420J2, limited at temperature extremes.

Corrosion resistance

Better than 420J2, thanks to its lower carbon
Suits mildly corrosive environments

Heat resistance

Good corrosion resistance at room temperature
Loses ductility at sub-zero temperatures
Loses strength at elevated temperatures through over-tempering
Tell us what the part is, where it will be used and roughly how many. We confirm the grade and finish before you order.
Tell us your application

Processing 420J1.

Machine it soft, then harden and temper.

Machining

Easy to machine when annealed; harder to machine once hardened.

Welding

Possible, but avoid welding in the annealed, hardened or tempered condition to prevent brittleness and cold cracking. Preheat, control interpass temperature, cool very slowly and anneal after welding.

Hot working

Improves toughness and wear resistance.

Cold working

Increases hardness and strength, and improves surface quality and dimensional accuracy.

Annealing

Heat uniformly to 840–900 °C (1544–1652 °F) and hold until the section is uniform, then soak and cool.

Hardening

Heat to 950–1020 °C (1742–1868 °F), hold until uniform, then quench in oil or cool in air.

Tempering

Reduces brittleness and internal stress after hardening.
Have a drawing, cut list or sample photo? Upload it and we review it and send you a quote.
Upload your drawing

420J1 physical and mechanical properties.

Typical physical values, and mechanical values for annealed cold-rolled sheet and strip (JIS G4305), the condition we supply it in.

Physical properties

Property
Value
Density
7.75 g/cm³
Modulus of elasticity
200 GPa (29 × 10⁶ psi)
Thermal expansion, 0–100 °C
10.4 µm/m·°C (5.8 × 10⁻⁶ /°F)
Thermal conductivity
24.9 W/m·K
Specific heat
0.11 Btu/lb·°F
Electrical resistivity
56 µΩ·cm

Mechanical properties, annealed (JIS G4305)

Property
Value
0.2% proof strength, min.
225 N/mm²
Tensile strength, min.
520 N/mm²
Elongation, min.
18%
Hardness, max.
223 HBW / 97 HRBS

Chemical composition, % by weight

Grade
C
Si
Mn
P
S
Cr
Ni
420J1
0.16–0.25
≤1.00
≤1.00
≤0.040
≤0.030
12.00–14.00
≤0.60
Tell us what the part is, where it will be used and roughly how many. We confirm the grade and finish before you order.
Tell us your application

Finishes and processing from Sanmei Metal.

Mill finishes, decorative finishes made in our own facility, and coil and sheet cut to your size.

Decorative finishes

Nickel Silver Hairline Stainless Steel Sheet S26HL-01 (3)
Hairline
Nickel Silver Satin Stianless Steel Sheet S26ST-01 (3)
Satin
black mirror polised stainless steel
Mirror
Nickel Silver Vibration Stainless Steel Sheet S26VB-01 (2)
Vibration
See all decorative finishes →

Mill finishes

Processing

Precision slitting
Cut to length
Shearing
Edge trimming
Blanking
Surface polishing
Tell us about your projectSend a sample photo or drawing

420, 420J1 and 420J2.

420J1 and 420J2 are branches of 420, made to meet different needs for hardness, strength and corrosion resistance. Adjusting the composition, above all the carbon, gives steels for different uses.
Tell us what the part is, where it will be used and roughly how many. We confirm the grade and finish before you order.
Tell us your application

The supplier you can trust.

Every order ships with a Mill Test Report.
Click a document to see it full size.
Get a quote with Mill Test Report

420J1 stainless steel FAQ.

Questions buyers ask before ordering 420J1.

What is the difference between 420J1 and 420J2?

420J1 has less carbon, 0.16–0.25% against 0.26–0.40%, so it has better corrosion resistance and reaches a lower hardness after heat treatment.
Explore
420J2

Is 420J1 magnetic?

Yes. It is a martensitic stainless steel and it is magnetic.

Can 420J1 be hardened?

Yes. Heat to 950–1020 °C, quench in oil or cool in air, then temper to reduce brittleness.

Can 420J1 be welded?

Yes, with care. Avoid welding in the annealed, hardened or tempered condition; preheat, control interpass temperature, cool very slowly and anneal after welding to prevent cracking.

What sizes do you supply?

Coil in 1000, 1219, 1240 and 1500 mm widths or slit to size, 0.15–3.0 mm thick. Sheet in the same widths, 2000 to 3048 mm long, 0.3–3.0 mm thick.
Question not answered here? Ask us directly and our team will reply in person.
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Why project buyers work with Sanmei Metal

Material-driven, engineering-supported, execution-ready. One supplier from the mill to your site.
1

Source from leading partner mills

Base coil from Lisco, Tisco, Jisco, Posco PZSS, Yongjin and Hongwang, each batch with its Mill Test Report.
Our mill partners
2

Finish in-house

PVD, water plating and surface finishing under one roof at our Foshan facility.
Decorative finishes
3

Engineer and fabricate

Our engineers review drawings so profiles and panels can be made and installed.
Architectural metal works
4

Protect and ship

Film matched to laser cutting or stamping, and crates or steel frames packed for sea freight.
Packing and filming
Technical questions about grades, finishes or tolerances?
Technical guide

Our Leading Coating Technology.

Thicker coating, consistent color and easy-clean surfaces. Each one measured in our own production and compared with typical market product.
PVD coating

Thicker PVD coating

0.30µm
Typical coating thickness, up to 28% thicker than a typical market coil, so the color lasts longer.
See the coating test
Color control

Consistent color

ΔE ≤ 2
Every coil is held below the color difference the eye can see, so panels from different batches match.
See the color data
Anti-fingerprint

Fingerprint-resistant

215solvent rubs
Our anti-fingerprint coating withstood 215 rubs with a strong solvent. The standard requires 100. Typical market AF failed at 70.
See the AF test
Tested to GB/T and ISO standards, with MTR and SGS reports on request.
See all our quality control.

Documents you can check.

Every order ships with a Mill Test Report traced to its heat number, and SGS testing is available on request. These are real documents from our mill partners and our project work.
Certifications shown belong to Sanmei and its fabrication partners. Click a document to see it full size.

Tell us about your project.

Send a drawing, a reference photo or just the grade and size. Our team replies with material advice, finish options, samples and a quote.
What helps us answer fastest
Drawing, sketch or reference photo
Grade and thickness, if you know them
Finish or color you have in mind
Quantity and delivery location
Tell us about your project →
Samples and small batches are welcome.

Contact us

Creating Center, Shunde District, Foshan City, Guangdong Province, 528315, China
+8615015653566 / 0757-87668353
Paige Deng
marketing@sanmeimetal.com

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    TEL: +8615015653566 / 0757-87668353
    Email: marketing@sanmeimetal.com

    Headquarters:
    Creating Center, No.142, Yuhe Road, Lecong Town, Shunde District, Foshan City, Guangdong Province, China. 528315

    Factory: Liyuan Logistics City, Chencun Town, Shunde District, Foshan City, Guangdong Province, China. 528313

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