General Information for Cast Iron GG20
||K - Cast Iron
MACHINABILITY OF GG20 CAST IRON
GG20 is a grey cast iron material with a machinability rating of 127% and hardness 205 HB.
Grey cast iron is the most brittle cast iron sub-group. It is the easiest to machine and produces tiny chips even when using a flat insert without a chip breaker.
In cast iron, the material standards also define the allowed hardness range, and hardness is the top-ranking factor affecting the machinability ratings. For example, nodular cast iron is known to be harder to machine compared with grey cast iron. However, if a grey cast iron alloy has a hardness of 300HB is will have lower machinability than nodular cast iron with 200HB.
Cast iron is very brittle and produces short chips. Therefore, there is no need for a sharp cutting edge, and a strong geometry with a large honing or K-land is the best choice.
For general turning of Cast Iron GG20 at stable conditions use a grade with a very hard substrate and CVD coating.
In case you are running at a cutting speed that is lower than 490 SFM (150 m/min), it is better to use a grade with a very hard substrate and PVD coating.
For general milling use a grade with a semi hard substrate and CVD coating.
For detailed carbide grades recommendations, check the table below.
Recommended Cutting speed range for turning at stable conditions is 820 - 1100 [SFM] / 250 - 335 [m/min].
Consider using CBN inserts. Although they cost more than twice, they enable increasing the cutting speed by 2-4 times (relative to carbide).
Recommended Cutting speed range for milling with stable clamping and short overhang 540 - 740 [SFM] / 165 - 225 [m/min]
For detailed cutting speed recommendations, check the table below.
Equivalent International Designations for Cast Iron GG20
Chemical Composition for Cast Iron GG20
Sorry, Not Availble for this Material
Cutting Speeds Recomendations for Grey cast iron - Pearlitic/Ferritic
Important! The speed estimation is given for an ideal situation:
- Most suitable carbide grade
- Stable tool clamping
- Stable workpiece clamping
- Good quality raw material
- A short overhang of the cutting tool.
- Nominal hardness of the material.
Recommended Carbide Grades for Cast Iron GG20
Grade for Milling (Indexable)
Recommended Insert Cutting Edge Geometry for Cast Iron GG20
||0.05-0.10 mm / 0.002-0.004"
||0.30-0.40 mm / 0.012-0.016"