Martensitic Stainless Steel (SUS420J2,RB-S)

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Knitting needles, loom reeds, spinning machines, doctor blades, blades, rulers, soldering irons, scrapers, HDD drive components, bearings, and various springs

Thickness：　0.050～2.5mm　　

　　Width：　3.0～300mm

JAPAN、SHANGHAI（Quenching is possible）

Product overview

SUS420J2, RB-S are classified as martensitic stainless steels, and their most notable feature is that they can be quenched.

They have a high carbon content and can acquire extremely high strength if quenched after purchase. By fine tuning the tempering process, it is possible to endow them with a wide range of mechanical properties.

At the same time, they have the drawback of being the most rust-prone stainless steels.

However, thanks to their ability to acquire high heat resistance and work hardening, they are used in a variety of applications such as those listed above.

As their high percentage of carbon makes them prone to rust, it is best to think of these stainless steels as being closer to iron.

Features

Features of each grade are described in the table below.

Grade	Features
SUS420J2	SUS420J2 is classified as a martensitic stainless steel. Thanks to its marketability, price, and other features, it is used in a wide range of fields. When shipped with an annealed finish, it contains completely spheroidized carbides, making it easily processed.
RB-S	RB-S is classified as a martensitic stainless steel. It has a higher carbon content than SUS420J2, giving it good quench hardening properties. It provides one of the highest levels of hardness of any stainless steel, and is used for blades and other applications. It is quite hard even with an annealed finish, which makes it unsuitable for complex processing, but ideal for blade applications.

Standard

TOKKIN Designation	International Standard	USA		Europe	UK	Germany	France	Russia	China	Japan
TOKKIN Designation	ISO	UNS	AISI	EN	BS	DIN	NF	ΓOCT	GB	JIS
SUS420J2	5	Ｓ42000	420	X30Cr13	420S45	X30Cr13	Z33C13	30X13	X30Cr13	SUS420J2
RB-S	TOKKIN's original material

Chemical composition

TOKKIN Designation	Chemical composition(%)
TOKKIN Designation	C	Si	Mn	P	S	Cr	Ni	Mo
SUS420J2	0.26～0.40	≦1.00	≦1.00	≦0.040	≦0.030	12.00～14.00	－	－
RB-S	0.58～0.70	≦1.00	≦1.00	≦0.040 *1	≦0.015 *2	12.50～14.50	－	－

*1 Less than 0.030　　*2 about 0.002

Tokkin Advantages

Excellent hardenability

By controlling carbide grain diameter, we are able to improve hardenability.

Reduced load on heat treatment furnace

Material can be quenched at a lower temperature or in a shorter time than normal, making it possible to reduce the load placed on the heat treatment furnace.

Custom-made thickness

Tokkin can provide micron-level customization of thickness for special applications such as razors and utility knife blades.

Excellent sharpenability

Our proprietary structure control provides improved sharpenability.

Made-to-order product that can be manufactured in small lots

We can supply custom-made products top suit your processing conditions.

Other manufacturers typically accept custom-made orders in one-ton units, but we are able to provide small lots starting from 300 kg.

Physical propaties

TOKKIN

Designation

Density

g/cm³

Specific heat

J(kg·K)

Coefficient of

thermal expansion

(0～100℃)10^-6/K

Thermal

conductivity

W/(m·K)

Electric

resistance

μΩ·cm

Young's modulus

N/mm²

SUS420J2

7.75

460

10.3×10-6/K

24.7

200,000

RB-S

7.70

430

25.0

220,000

Mechanical properties

TOKKIN Designation	Finishing condition	Hardness	Tensile strength　　　Elongation
TOKKIN Designation	Finishing condition	HV	N/mm²	%
SUS420J2	Annealed	150～200	540～655	20～30
SUS420J2	Full hard	280～320	880～1030	1～3