Cutting Iron

We get a lot of jobs that we need to cut Powdered iron bearings for different companies and they eat up my inserts. Any suggestion on speeds, feeds, DOC, and insert grades and types. We are using carbide inserts all the time and are cutting very slowly so I'm curious if there is a better process.

Amanor said:

We get a lot of jobs that we need to cut Powdered iron bearings for different companies and they eat up my inserts. Any suggestion on speeds, feeds, DOC, and insert grades and types. We are using carbide inserts all the time and are cutting very slowly so I'm curious if there is a better process.

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more than likely its more than just powdered iron. think of sand mixed in and you realize its abrasive. sure not going the highest feeds and speed and width and depth of cuts helps but sometimes all you can get is a 20 to 30 minute tool life.
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and maybe different carbide type and coating might help some. usually if you ask industrial supply place they might have something on the shelf locally you can try. not unusual to find catalog with 100 different types and 90% is special order or not made anymore. sometimes easier to ask whats easily available rather than depend on what catalog says. special order stuff in catalog sure if you order over $10,000 and can wait when they make it once of twice a year you can get special stuff. small orders easier to ask whats commonly available.

Check into CBN inserts if you can fixture the bearings well enough (CBN likes rigidity). Run higher speed and moderate feed, up both as you figure out the process.

like anything there is a cost of tooling to time savings math formula.
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if you spend $50,000/yr more on tooling trying to save $25,000/yr often the math is going to say what is worth it. often need to try different things and collect data not opinions. facts often say what might at first seem not logical

You might try a very chunky/thick insert with a negative land at the top edge. yes still very sharp at cutting edge then with a perhaps 5* negative top.
Chunky absorbs the heat, negative allows much more stock for reducing cratering. (the effect of the top of the insert to wear away just behind the edge)

Cast iron often fractures above the insert and the actual cutting edge often does barley touch the part.
Good to have very stout machine and fixtures.
Flood or dry..whimpy coolant is not good.

Are you running these parts DRY?

Stuart

No we always use coolant

larger castings always use coolant on cast iron.
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if you are using 10 to 30 hp that creates large amounts of heat like approximately like 7000 to 21,000 watt heater. if you aint lost visibility cause cutter in a cloud of steam you aint doing much. another reason coolant is used its often like a firemans hose coming out at high pressure and volume to flush the chips down to the chip auger. literally i wouldnt want to be hand shoveling 500 to 1000 lbs of chips per day by hand. i have had to do when chip conveyor not working and its definitely a lot of work
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5 gallon bucket full of chips is heavy. and lifting every 1/2 to 1 hour into chip lugger by hand is hard back breaking work