PRODUCT DATA ②
■ Guaranteed Range of Hardness of the Ejector Sleeve and Center Pin Base Material Straight Ejector Sleeves Center Pins
■ Guaranteed Range and Hardness of Nitriding and Surface Hardness
Straight Ejector Sleeves
Center Pins
x 2
b 2 (Guaranteed Range of Base Material Hardness)
※ Cross-sectional view
※ Cross-sectional view
T ＋ 2
x 2
b 2
(Guaranteed Range of Base Material Hardness)
T ＋ 2
x 3
b 3 (Guaranteed range of nitrided surface hardness)
Annealed head
x 3
b 3 (Guaranteed range of nitrided surface hardness)
Annealed head
③
① ②
L
②
③
①
L
①
②
b 2 ≧ L–x 2 max.
b 2 ≧ L–x 2 max.
F
①
②
L
Stepped Ejector Sleeves
Stepped Center Pins
b 3 ≧ L–x 3 max.
b 3 ≧ F–x 3 max.
x 2
b 2 (Guaranteed Range of Base Material Hardness)
T ＋ 2
x 2
b 2 (Guaranteed Range of Base Material Hardness)
T ＋ 2
Stepped Ejector Sleeves
Stepped Center Pins
Annealed head
※ Cross-sectional view
※ Cross-sectional view
Annealed head
x 4 （ x 4 ＝ N ）
③
① ②
（ x 4 ＝ N ） x 4
b 4 (Guaranteed range of nitrided surface hardness)
L
b 4 (Guaranteed range of nitrided surface hardness)
③
① ②
L
b 2 ≧ L–x 2 max.
b 2 ≧ L–x 2 max.
Hardness of the Ejector Sleeve and Center Pin Base Material
②
Head thickness (T)
②
①
Classification
M Material
x 2 max.
①
③ (Guaranteed range of base material hardness)
①
②
N
N
F
L
T4 (4mm)
58–60HRC Overall quenching (no annealing)
58–60HRC Overall quenching (no annealing)
Ejector sleeves
0
58–60HRC
b 4 ≧ L–x 4 (x 4 = N)
b 4 ≧ F – x 4 (x 4 = N)
JIS (6/8mm )
SKH51
T4 (4mm)
30
28–35HRC (reference value)
28–60HRC (reference value)
58–60HRC
Ejector Sleeve and Center Pin Surface Hardness ①
JIS (4/6/8mm)
35
Head thick- ness (T)
M Material
x 3 max.
② (Guaranteed range of nitrided surface hardness)
SKD61
T4 (4mm)
40
28–45HRC (reference value)
28–55HRC (reference value)
50–55HRC
Center Pins
T4 (4mm)
T4 (4mm) ECB/ECBB T4 (4mm)
10
40
28–45HRC (reference value)
28–45HRC (reference value)
40–45HRC
JIS (4/6/8mm) T10 (10mm)
–
900HV–
Base material hardness
SKD61 + Nitriding
900HV–
T4 (4mm) ECB/ECBB
37–43HRC (no annealing)
37–43HRC (no annealing)
0
37–43HRC
SKD61 + Nitriding
(without nitrided layer)
(with nitrided layer)
JIS (4/6/8mm) T10 (10mm)
40
T4 (4mm)
30
Ejector sleeves
JIS (4/6/8 mm)
35
28–43HRC (reference value)
28–43HRC (reference value)
37–43HRC
T10 (10mm)
40
• Nitriding
Nitriding is one of the steel surface treatment methods.
SKD61 to achieve a level of 30HRC. Annealing is performed on heads of SKD61 + Nitriding to achieve a level
• Annealing is performed on heads of SKH51
(Nitrided)
The steel is placed in a furnace that is then filled with nitrogen gas, and at high temperatures (around 500°C) a hardened layer combined with the nitrogen is formed on the surface of the steel.
of 40HRC.
• Nitrided
This refers to the depth of the hardened layer formed on the surface of the steel by nitriding treatment.
■ Ejector Sleeve and Center Pin Surface Hardness
Depth
The nitrided depth of MISUMI's plastic mold ejector sleeve and center pin Hardness of 900HV– is 0.003–0.008 mm (reference value), and the depth at which the hardness of steel increases due to the combination with nitrogen is 0.1 mm from (reference value) than the surface. The nitrided depth of straight ejector sleeve and center pin is controlled by adjusting nitriding temperature and treatment time in accordance with shaft diameter size. In the case of stepped ejector sleeves and center pins, nitrided depth is controlled by adjusting nitriding temperature and treatment time in ac- cordance with tip diameter (P) size. For this reason, the surface hardness of the retention diameter (D) is slightly lower at around 500HV (reference value).
Normally, it is quite easy to file down an ejector sleeve and center pin using a regular file (metalworking file). The nitriding treatment applied to the surface of SKD61 + Nitriding makes it difficult to file down because the file does not bite as easily into the surface. The nitrided layer is several microns thick, so a little pressure should be applied to the file. ＊ Most regular metalworking files have a hardness of 68 to 70HRC.
Metalworking le
Ejector Sleeve
M SKH51 (JIS high–speed steel)
M SKD61 (JIS die steel) prehardened, and nitrided
• Ejector
The guaranteed range of nitrided surface hardness for ejector sleeves (b3, b4) only applies to the outer diameter surface.
70HRC
70HRC
About 68–70HRC
Metalworking le (Reference value)
Metalworking le (Reference value)
Sleeves
The inner diameter surface is outside the guaranteed range of nitrided surface hardness
About 68–70HRC
68HRC
65HRC
• Center
Nitriding has not been done on the tip section of the center pins, in order to prevent chipping.
Cutting tool (Reference value)
Pins
SKH51
66HRC
60HRC
About 64–67HRC
55HRC
64HRC
(Common quenched) (Example) Plate etc.
Punching for press mold
About 61–64HRC
SKH51
SKD61
50HRC
62HRC
About 48–52HRC
(Reference value)
45HRC
60HRC
Ejector sleeve for plastic mold
SKH51
About 58–60HRC
Ejector sleeve for plastic mold
SKD61
40HRC
About 37–43HRC
58HRC
223
224
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