Materials to be tested

Hardness scales

7 types Impact device

D/DC

D+15

C

G

E

DL

Steel and cast steel

HRC

20～68.5

19.3～67.9

20.0～69.5

22.4～70.7

20.6～68.2

HRB

38.4～99.6

47.7～99.9

37.0～99.9

HRA

59.1～85.8

61.7～88.0

HB

127～651

80～638

80～683

90～646

83～663

81～646

HV

83～976

80～937

80～996

84～1042

80～950

HS

32.2～99.5

33.3～99.3

31.8～102.1

35.8～102.6

30.6～96.8

Cold work

tool steel

HRC

20.4～67.1

19.8～68.2

20.7～68.2

22.6～70.2

HV

80～898

80～935

100～941

82～1009

Stainless steel

HRB

46.5～101.7

HB

85～655

HV

85～802

Grey cast iron

HRC

HB

93～334

92～326

HV

Nodular cast iron

HRC

HB

131～387

127～364

HV

Cast aluminium alloys

HB

19～164

23～210

32～168

HRB

23.8～84.6

22.7～85.0

23.8～85.5

BRASS(copper-zinc alloys)

HB

40～173

HRB

13.5～95.3

BRONZE(copper-aluminium/tin alloys)

HB

60～290

Wrought copper alloys

HB

45～315

Common application for each impact device

DC: Test hole or hollow cylindrical

D+15:

Test groove or reentrant surface

C:Test small, light, thin parts and surface of hardened layer

G:

Test large, thick, heavy and rough surface steel

E: Test super high hardness material

DL: Test slender narrow groove or hole

Items

DC(D)/DL

D+15

C

G

E

Impacting energy

Mass of impact body

11mJ

5.5g/7.2g

11mJ

7.8g

2.7mJ

3.0g

90mJ

20.0g

11mJ

5.5g

Test tip hardness:

Dia. Test tip:

Material of test tip:

1600HV

3mm

Tungsten carbide

1600HV

3mm

Tungsten carbide

1600HV

3mm

Tungsten carbide

1600HV

5mm

Tungsten carbide

5000HV

3mm

synthetic diamond

Impact device diameter:

Impact device length:

Impact device weight:

20mm

86(147)/ 75mm 50g

20mm

162mm

80g

20mm

141mm

75g

30mm

254mm

250g

20mm

155mm

80g

Max. hardness of sample

940HV

940HV

1000HV

650HB

1200HV

Mean roughness value of sample surface Ra:

1.6μm

1.6μm

0.4μm

6.3μm

1.6μm

Min. weight of sample:

Measure directly

Need support firmly

Need coupling tightly

>5kg

2～5kg

0.05～2kg

>5kg

2～5kg

0.05～2kg

>1.5kg

0.5～1.5kg

0.02～0.5kg

>15kg

5～15kg

0.5～5kg

>5kg

2～5kg

0.05～2kg

Min. thickness of sample Coupling tightly

Min. layer thickness for surface hardening

5mm

≥0.8mm

5mm

≥0.8mm

1mm

≥0.2mm

10mm

≥1.2mm

5mm

≥0.8mm

Size of ball tip indentation

Hardness 300HV

Indentation diameter

Depth of indentation

0.54mm

24μm

0.54mm

24μm

0.38mm

12μm

1.03mm

53μm

0.54mm

24μm

Hardness 600HV

Indentation diameter

Depth of indentation

0.54mm

17μm

0.54mm

17μm

0.32mm

8μm

0.90mm

41μm

0.54mm

17μm

Hardness 800HV

Indentation diameter

Depth of indentation

0.35mm

10μm

0.35mm

10μm

0.35mm

7μm

--

--

0.35mm

10μm

No.

Type

Sketch of non-conventional

Supporting ring

Remarks

1

Z10-15

For testing cylindrical outside surface

R10～R15

2

Z14.5-30

For testing cylindrical outside surface R14.5～R30

3

Z25-50

For testing cylindrical outside surface

R25～R50

4

HZ11-13

For testing cylindrical inside surface

R11～R13

5

HZ12.5-17

For testing cylindrical inside surface

R12.5～R17

6

HZ16.5-30

For testing cylindrical inside surface

R16.5～R30

7

K10-15

For testing spherical outside surface

SR10～SR15

8

K14.5-30

For testing spherical outside surface SR14.5～SR30

9

HK11-13

For testing spherical inside surface

SR11～SR13

10

HK12.5-17

For testing spherical inside surface

SR12.5～SR17

11

HK16.5-30

For testing spherical inside surface

SR16.5～SR30

12

UN

For testing cylindrical outside surface, radius adjustable R10～∞