<p>My experience with cast iron in the process of milling and lathe turning (minimal, but valid reference) is that cast iron will cut nicely with ordinary HSS tools. The swarf will be granular, not long streams of ribbon and the surface will be moderately smooth, depending on your feed and speed.</p>

<p>A few references on the 'net suggest that it is "self-cooling" due to graphite in the iron. Another few references also suggest that use of coolant will create abrasive mud which will dull the tools.</p>

<p>You won't be destroying your tools.</p>

CC BY-SA 4.0
2019-07-07T22:04:22.240Z
In grey iron the graphite flakes are "chip breakers"  preventing long swarf.
blacksmith37
CC BY-SA 4.0
2019-07-07T01:22:23.023Z
2019-07-07T01:22:23.023Z
fred_dot_u
<p>If it is grey cast iron ( most probable) it will cut like tough wood- no special tools at all. If nodular of malleable cast irons it will be slightly more difficult to machine ( more ductile , similar to ordinary carbon steel) but no special tools. It should not be white iron as that is brittle.  </p>

CC BY-SA 4.0
2019-07-08T00:42:15.737Z
ASM recommends  35 to 175 surface feet/minute for milling depending on grade , with feed of 0.008 to 0.016 in./turn ( hss tools). They suggest no cutting fluid as the small chips from cast iron cake-up and are difficult to remove from work and tools.
blacksmith37
CC BY-SA 4.0
2019-07-07T01:20:04.053Z
2019-07-07T01:20:04.053Z
blacksmith37
<p>I need to add a slot to the table plate of my Harbor Freight (Central Machinery) ½ ton arbor press.</p>

<p>It's obviously cast iron, but the surface is polished, so I'm not sure of its exact composition or if the surface is tough and it has a softer interior.</p>

<p>I don't have any carbide end mills, but I have some surplus HSS mills I don't mind destroying in this process.</p>

<p>Any ideas or suggestions?</p>

<p>Thanks!</p>

<metalworking>
Milling an additional slot in an arbor press table plate?
RoUS
# Milling an additional slot in an arbor press table plate?

(Asked by: username_0 on 2019-07-06)

I need to add a slot to the table plate of my Harbor Freight (Central Machinery) ½ ton arbor press.

It's obviously cast iron, but the surface is polished, so I'm not sure of its exact composition or if the surface is tough and it has a softer interior.

I don't have any carbide end mills, but I have some surplus HSS mills I don't mind destroying in this process.

Any ideas or suggestions?

Thanks!

**Tags:** metalworking


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## 2 answers

### Answer by username_1 on 2019-07-07. Score: 2 | Accepted answer

My experience with cast iron in the process of milling and lathe turning (minimal, but valid reference) is that cast iron will cut nicely with ordinary HSS tools. The swarf will be granular, not long streams of ribbon and the surface will be moderately smooth, depending on your feed and speed.

A few references on the 'net suggest that it is "self-cooling" due to graphite in the iron. Another few references also suggest that use of coolant will create abrasive mud which will dull the tools.

You won't be destroying your tools.

> **Comments:**
> **username_2**: In grey iron the graphite flakes are "chip breakers"  preventing long swarf.  

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### Answer by username_2 on 2019-07-07. Score: 1

If it is grey cast iron ( most probable) it will cut like tough wood- no special tools at all. If nodular of malleable cast irons it will be slightly more difficult to machine ( more ductile , similar to ordinary carbon steel) but no special tools. It should not be white iron as that is brittle.

> **Comments:**
> **username_2**: ASM recommends  35 to 175 surface feet/minute for milling depending on grade , with feed of 0.008 to 0.016 in./turn ( hss tools). They suggest no cutting fluid as the small chips from cast iron cake-up and are difficult to remove from work and tools.  

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