Starrett 3811A - Page 23

23
Table 3
Type of impact device
DC(D)/D
L
D+15
C
G
Impacting energy
Mass of impact body
11mJ
5.5g/7.2
g
11mJ
7.8g
2.7mJ
3.0g
90mJ
20.0g
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
Impact device diameter:
Impact device length:
Impact device weight:
20mm
86(147)/
75mm
50g
20mm
162mm
80g
20mm
141mm
75g
30mm
254mm
250g
Max. hardness of
sample
940HV
940HV
1000HV
650HB
Mean roughness value
of sample surface Ra:
1.6μm
1.6μm
0.4μm
6.3μm
Min. weight of sample:
Measure directly
Need support firmly
Need coupling tightly
>5kg
2～5kg
0.05～2k
g
>5kg
2～5kg
0.05～2kg
>1.5kg
0.5～1.5kg
0.02～0.5kg
>15kg
5～15kg
0.5～5kg
Min. thickness of
sample Coupling tightly
Min. layer thickness for
surface hardening
5mm
≥0.8mm
5mm
≥0.8mm
1mm
≥0.2mm
10mm
≥1.2mm
Size of tip indentation
Hardnes
s 300HV
Indentatio
n diameter
Depth of
indentation
0.54mm
24μm
0.54mm
24μm
0.38mm
12μm
1.03mm
53μm
Hardnes
s 600HV
Indentatio
n diameter
Depth of
indentation
0.54mm
17μm
0.54mm
17μm
0.32mm
8μm
0.90mm
41μm
Hardnes
s 800HV
Indentatio
n diameter
Depth of
indentation
0.35mm
10μm
0.35mm
10μm
0.35mm
7μm
--
--
Available type of impact
device
DC: Test
hole or
hollow
cylindrical;
DL:Test
narrow
groove or
hole
D+15:
Test grooves
C: Test small,
light,thin
parts and
surface of
hardened
layer
G: Test
large,
,heavy and
rough
surface
steel