CCT diagram

Physical properties
Thermal expansion rate

800

Temp.
×10-6/K

700

Temperature (℃)

Quenching: 830℃×1h, Gas coolingTempering: 180℃×1h, TwiceHardness: 63HRC

Austenitizing: 825℃×10min

900

600

A

Temp.
W/m・K

500
B

400

25℃
29.9

Specific heat

100

863

869

0
14sec

15Temp.
J/kg・K

R88

Ms
M

60

104min

102

100℃
30.8

200℃ 300℃ 400℃
31.9
35.0
35.1

500℃ 600℃
33.6
32.0

＊Accuracy of repeated measurements is about ±10%.

300200GOATM

20〜100℃ 20〜200℃ 20〜300℃ 20〜400℃ 20〜500℃ 20〜600℃
11.7
13.0
13.0
10.6
10.8
11.5

Thermal conductivity

P

Daido’s Cold Work Die Steel Series

855
635
15321
413

271
289
60103

4br
4h104

Time (sec)

25℃
517

100℃
537

200℃ 300℃ 400℃
566
588
626

Young’s modulus / Rigidity modulus / Poisson’s ratio (25℃)

253

Features

Young’s modulus Rigidity modulus Poisson’s ratio

15

105

200GPa

77GPa

0.29

◆ High cleanliness by vacuum degassing in refining process.
◆ High hardness attained even with products of relatively large size because of better
hardenability compared with JIS SKS3.
◆ Excellent wear resistance by uniformly distributed fine tungsten and chrome carbides.
◆ Excellent machinability resulting from completely spheroidized microstructure.

TTT diagram
Austenitizing: 825℃×10min900

Excellent Hardenabilit y and Wear ResistanceSpecial Tool Steel

500℃ 600℃
666
728

800

Temperature (℃)

700Main applications

600

Application

500

Cold press

400

Hardness

Trimming dies, Forming dies, Punch

58〜62HRC

Coining dies

300
200

58〜62HRC

Shear bladeMs

100

Sheets (less than 6 mm)

58〜62HRC

Plates (6〜8 mm)

55〜60HRC

Gauges

04sec

1

1560

10104min215103Time (sec)604br4h104105

Chemical composition

Tokyo Head Office

Daido Shinagawa Building, 6-35, 1-Chome, Konan, Minato-ku, Tokyo, Japan
Phone: +81-3-5495-1270 Fax: +81-3-5495-6739

Bangkok OfficeUnit2-1, 22nd Fl., Silom Complex Bldg., 191, Silom Road, Silom,Bangrak, Bangkok 10500, Thailand
Phone: +66-2-231-3214 Fax: +66-2-231-3216

Daido Steel Group Europe GmbH

Insterburger Strasse 16, 60487 Frankfurt am Main, Germany
Phone: +49-69-29802867-0 Fax: +49-69-29802867-40

Daido Steel (America) Inc.

1051 Perimeter Drive, Suite 1175, Schaumburg, Illinois 60173, U.S.A.
Phone: +1-847-517-7950 Fax: +1-847-517-7951

Daido Steel (Shanghai) Co.,Ltd

Room 1402, Ruijin Building, 205 Mao Ming Nan Road, Shanghai, 200020, China
Phone: +86-21-5466-2020 Fax: +86-21-5466-0279

Daido Steel (Shanghai)Co.,Ltd
Guangzhou Subsidiary Company

Room 2601, No.8, Linhezhoug Road, Tianhe District, Guangzhou, 510610, China
Phone: +86-20-3877-1632 Fax: +86-20-8550-1126(Tool Steel Overseas Marketing & Sales Dept.)60〜64HRC

15

Chemical composition (%)

DAIDO
BrandCSiMnGOA

0.9

0.3

1.2

PSCu

≦0.030 ≦0.030 ≦0.25

NiCrMoWSpecialelements

≦0.25

0.5

0.1

0.5

Added

Heat treatment

GOA is a Registered trademark or Trademark of Daido Steel Co., Ltd.

■ Document Disclaimer
The product characteristics included in this brochure are the representative values based on the result of our measurements, and do not guarantee
the performance in use of the products.
Please inquire the latest information to our department in charge as the information of this brochure is updated without previous notice as needed.
Copyright ⓒ2019 Daido Steel Co., Ltd. All rights reserved.
No.SC1812b 24.06.0,0 (DDD)

Re-forging
Temp.
(℃)
850〜1100

Heat treatment (℃)

Hardness

Quenching Tempering

Annealed(HBW)

Quenched &Tempered(HRC)

750〜800 800〜850 150〜200
Slow cooling Oil quenching Air cooling

≦ 217

≧ 61

Annealing

Transformation Temp. (℃)
AcAr

Ms

708〜726―160
Austenitizedat 825

Properties(Except for Dimensional changes)

Hardenability (End-quench test)

Quenched hardness & Retained austenite
Specimen: Φ30×100mm
Holding time at quenching: 10minSpecimen: Φ25×100mm

7066
65

GOA 830℃5064SKS3830℃

403020Spherodized annealing

After quenching tempering(x 400)01020304050

Distance from quenched end of specimen (mm)(x 400)Retained austenite (%)

Hardness (HRC)

60

Hardness (HRC)

Microstructure

Material size: Φ36

20
15
10
5790

810

830

850

870

Austenitizing temperature (℃)

Tempering hardness

Tempering hardness

Tempered more than twice in case of wire cutting.

25mm dia.
(thickness)

Air cooling

Hardness (HRC)

60min

Oil quenching

See tableon the right60

Tempering temperature: 180~200℃

Quenching temperature: 830℃600~650℃

70Tempering

Ordinary quenching

Specimen: Φ30×10mm
Quenching: 830℃×30min, oil quenching

5040Specimen: Φ25×50mm
Quenching: 830℃×30min, oil quenching

0.2
Dimensional change (%)

Quenching

Dimensional change

Length0.1
Diameter

300As
quenched

20

100
As
quenched

200

300

400

500

600

100

200

300

400

Tempering temperature (℃)

Tempering temperature (℃)

See tableon the right

Hot bath: 150~200℃
15~20minAir cooling

Dimension
Dia./
Thickness(mm)

Immersiontime(min)Dimension
Dia./
Thickness(mm)

Time(min)105~ 82530

208~10100803010~151251005020~2520012010030~40500200

PackagedheatingToughness
40Soakingtime

20~45min.
Box wallthinkness:
25mm

Wear resistanceSpecimen: 10R Notched, 2mm depth

3020101008
Wear amount (x 10-5 mm3/J)

Quenching temperature: 830℃
600~650℃

Electric furnace
Gaseous atmosphere furnace

Salt bath

Charpy impact value (J/cm2)

Martempering (Hot bath quenching)

SKS3
64300

Tempering temperature (℃)×1h, AC

Test conditions

20200GOA

Test method: Ogoshi-type wear test
Load: 6.5kg
Sliding distance: 200m
Rotation disc: SK5 (85HRB)

01

2

Sliding speed (m/sec)

3