Skip to main content
CNC Feeds & Speeds

Cast Iron Machining Reference

Record the iron type and supplied condition before looking up cutting data. A general cast-iron label can hide important differences between the material assumed by a tooling chart and the component on the machine.

Identify The Casting Material

Gray, ductile and other iron types should be identified from the available specification. Do not transfer a reference condition solely because two components are castings. The calculator does not inspect casting skin, local variation or the condition of a particular surface.

Use The Appropriate Diameter

For milling, use the cutting diameter required by the source relationship. For turning, use workpiece diameter at the cut. A large cutter at moderate RPM can still have substantial surface speed, so RPM alone is not enough for comparing setups.

A Surface-Speed Example

An assumed 80 mm diameter at 500 RPM gives approximately 125.7 m/min. This is a geometry calculation. It does not identify an appropriate insert grade, cutting speed or coolant practice for a casting.

Review The Whole Setup

Keep tool grade, geometry and the source operation notes with the cutting values. The MRR calculator estimates volume from engagement and feed; it does not predict force or interrupted-cut performance. Use supplier instructions and the actual component conditions when evaluating a first cut.

Open The Feed & Speed Calculator | Browse Material References

Cast Iron Is More Than One Material Entry

Sandvik Coromant distinguishes grey, nodular, malleable, compacted graphite and austempered ductile iron in its cast-iron milling reference. These families should remain separate when reading supplier application information. The name casting identifies a manufacturing route, but it does not establish which iron material is on the machine.

Example FamilyInformation To Keep
Grey ironThe actual grade, supplied condition and tool supplier’s matching material entry.
Nodular or ductile ironIts own specification and condition rather than a grey-iron substitute.
Compacted graphite iron (CGI)The component designation and tooling guidance that explicitly covers it.

Use Case: Comparing Two Cast-Iron Milling Jobs

Identify the iron family on each job, then compare the cutter grade and operation conditions before comparing feed values. Sandvik’s cast-iron milling insert and grade reference explains its application categories. Use the milling MRR calculator to compare volume at known engagement; it cannot select an insert grade or predict interrupted-cut behaviour.

Supplier product guidance describes its own application choices. Match the actual iron specification and current tooling documentation before transferring a condition.

Cast Iron Reference Questions

Does The Calculator Identify Casting Skin Or Material Variation?

No. It only processes entered numbers. Establish the iron type and relevant component conditions from the specification and tooling guidance.

Does A Removal-Rate Result Confirm Insert Suitability?

No. The MRR calculation estimates volume. Insert grade, geometry and application suitability require the relevant tool data.

Help Improve This Resource

Request A Tool

Describe the calculation your workflow needs, the inputs you already have and the output you want to check. Include units and an example without confidential job details.

Request A Tool

Report An Error

Share this page address, the entered values and the result you expected. Include the source of your comparison so the formula, units and explanation can be investigated.

Report An Error

CNC Feeds & Speeds Editorial Desk

The site brings calculation tools and machining references into one workspace. Use the editorial and site information to understand its purpose and limitations. Send corrections with a reproducible example through the error report form.