Starting cutting speed in m/min and sfm, feed in mm/rev and ipr, the carbide grade class and the setup by operation for EN-GJL-250 (W.-Nr. EN-JL1040). The numbers are the published K01 Grey cast iron (soft) sub-group starting band; the designations are on the cross-reference page.
| Item | Value |
|---|---|
| ISO 513 group | K Cast iron |
| Sub-group | K01 Grey cast iron (soft) |
| Sub-group hardness / condition | 180–220 HB |
| Category | Grey cast iron |
| EN / Werkstoffnummer | EN-GJL-250 (GG25) · EN-JL1040 |
Hardness is the range published for the whole K01 Grey cast iron (soft) sub-group on our material guide; the delivery condition of your EN-GJL-250 may sit anywhere inside it or outside it.
At least one designation of this material is a nearest commonly-cited counterpart, not a same-composition equivalent. The machining values below belong to the sub-group, so confirm the actual alloy and delivery condition on the material certificate.
| Condition | Vc m/min | Vc sfm | Feed mm/rev | Feed ipr |
|---|---|---|---|---|
| K01 Grey cast iron (soft), 180–220 HB | 150–350 | 490–1150 | 0.10–0.50 | .004–.020 |
Sub-group starting values for carbide inserts, from K01 Grey cast iron (soft). They describe the whole sub-group and are not tuned to EN-GJL-250. sfm and ipr are converted from the metric values (1 m/min = 3.281 sfm, 25.4 mm = 1 in). The published band is per sub-group, not per operation; the table below gives the setup by operation. Convert Vc to spindle speed with the speeds & feeds calculator, and see the speeds & feeds guide for the ISO K group range.
| Operation | Geometry | Coating family | Coolant | First check |
|---|---|---|---|---|
| Roughing | Negative geometry, honed edge for cast skin | CVD alumina (Al₂O₃)-coated carbide | Dry is acceptable | Abrasive flank wear: keep the speed sensible |
| Finishing | Negative geometry; short chips, no built-up edge | CVD alumina carbide; ceramic for high-speed finishing | Dry is acceptable | Flank wear drifting the size |
| Interrupted cut | Honed edge for cast skin and interruptions | CVD alumina carbide | Dry is acceptable | Edge chipping on skin; ease into the first cut |
| Low rigidity / thin wall | Negative geometry with a honed edge; support the part | CVD alumina carbide | Dry is acceptable | Frittering at the cut exit: reduce feed at exit |
Setup rows are the selection table of the K01 Grey cast iron (soft) guide. They carry no speeds, so they do not change the starting band above.
Same sub-group, same starting band: EN-GJL-200
CVD alumina (Al₂O₃)-coated carbide, K10–K20: alumina resists the high-temperature abrasion of grey iron. Ceramic for high-speed finishing.
The P, M, K, N, S or H number inside a grade range describes what the grade is built for, not the workpiece sub-group number, and the two scales must not be matched to each other. We name no single grade here: none of our published sources ties a named grade to this alloy. Pick by ISO class, then compare what the makers publish on the ISO K grade list and in the grade chart.
EN-GJL-250 (GG25), Werkstoffnummer EN-JL1040, US ASTM A48 Class 35 (nearest), JIS FC250. The full table, with the nearest-match flags, is on the EN-GJL-250 / A48 Class 35 cross-reference page.
Grey iron is graded by tensile strength, so cross-standard matches are nearest-by-class. Short chips, abrasive cast skin: run dry, take the first cut under the skin, K-group data.
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The published starting band for the K01 Grey cast iron (soft) sub-group is 150–350 m/min (490–1150 sfm) at 0.10–0.50 mm/rev (.004–.020 ipr). It is a starting band for the whole sub-group, not a value tuned to EN-GJL-250, so confirm on a sample part and adjust for condition, tool and rigidity.
CVD alumina (Al₂O₃)-coated carbide, K10–K20: alumina resists the high-temperature abrasion of grey iron. Ceramic for high-speed finishing. Pick the grade by ISO class rather than by brand name, then confirm the exact grade for your condition. We name no single grade here because none of our published sources ties a named grade to this alloy.
EN-GJL-250 (GG25) (Werkstoffnummer EN-JL1040); US: ASTM A48 Class 35 (nearest); JIS: FC250. At least one pairing is nearest-by-properties, not a drop-in equivalent: the material certificate decides.
The advisor compares what the makers publish for your material and operation and shows the source behind each answer, or tells you it could not verify.