When parting it is recommended to use an insert as narrow as possible in order to save material and minimise cutting forces.
Long overhangs (ar) causing instability could result in tool failure and poor component quality.
The recommended overhang should not exceed 8 x la (width of insert). | |
Select correct width, geometry and system for parting of bars
| Component dia, mm | Insert width,
la, mm | Insert geometry | Tool system | Feed start value, mm/r |
< 8 | 1 | CM/CS | CoroCut 3 | 0.05 |
8 - 12 | 1.5 | CM | CoroCut 2 & 3 | 0.07 |
12 - 16 | 2 | CM | CoroCut 2 | 0.08 |
16 - 24 | 2.5 | CR | CoroCut 2 | 0.08 |
24 - 32 | 3 | CR | CoroCut 2 | 0.12 |
32 - 40 | 4 | CR | CoroCut 2 | 0.15 |
40 - 48 | 5 | 4E | Q-Cut | 0.18 |
48 - 56 | 6 | 4E | Q-Cut | 0.20 |
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Recommended grade and cutting data
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Starting grade is GC2135.
Cutting speed 125 m/min. |
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Pip free parting
To avoid or minimise pips use right hand style or left hand style ground inserts with smallest possible front angle that gives an acceptable component.
Inserts with 5° front angle are available in CF, CM and CR geometries. Inserts with 10° and 15° front angle are available in CS geometry.
Note that a large front angle reduces pips, but will not produce a straight cut and give poorer surface finish and shorter tool life.
For straight parting and high stability use a screw clamp holder with the shortest overhang, ar. A reinforced toolholder will increase the stability even more. |
Screw clamp holder
with short ar. | Reinforced blade. |
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Parting – small diameter bars
When parting off small diameter bars, ensure the lowest possible forces are generated.
Use inserts with smallest possible width and sharpest edges, i.e. CS or CF geometries.
The precision ground CoroCut XS having widths down to 0.7 mm and 15° front angled for pip-free parting are ideal for these types of applications. | |
Case story
 | Machining specification
Operation: Parting off to centre
Material: JIS SCM 415, CMC 02.1, HB 240
Toolholder: LF123F10-2525B
Insert: N123F2-0250-003-CR
Grade: GC1125
| Cutting data | Competitor | Sandvik Coromant |
| Width of insert: | 2.0 mm | 2.0 mm |
| Cutting speed: | 129 m/min | 129 m/min |
| Feed (reduced at the end): | 0.05 mm/r | 0.07 mm/r |
| Time in cut: | 0.11 min | 0.08 min |
| Components: | 1200 pcs | 2600 pcs |
Tool life +116%
Productivity +40%
Annual time saving 175 hours |
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