# Annular cutter chattering



## Aukai (Jun 4, 2021)

I am trying to make 3/16 flat washers out of 316 SS using 1/2", and a 2" annular cutter 210, and 345 RPM both chatter. I also tried cutting fluid, and flooding water soluble, both did the same. I only have hand feed on the G0755. I'm open for suggestions on what I'm missing. Thank you.


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## mikey (Jun 4, 2021)

Feed more aggressively. It is likely that you are trying to cut into a work-hardened face.


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## Aukai (Jun 4, 2021)

OK, I try not to force too much, but will try more pressure. I have exploded 2 annular cutters in the past, both were Slugger by Fein cutters, never broke a Haugen....


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## mikey (Jun 4, 2021)

I dunno' about you but when I have to cut into a previously machined surface in 316, I don't fool around. The hardened layer may be only a tenth or less deep and I want to get under it fast so I can get to cutting again.

Another way to do this is to turn the chuck by hand and feed hard at the same time. This works especially well when parting on the lathe. It is clear when the tool begins to cut again and then you can turn power on again.


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## Aukai (Jun 4, 2021)

Popped the 1/2" annular cutter, and broke the R8 locator pin in the spindle too but, finished up with my Cobalt 1/2" drill bit. The previous holes that I drilled for the mounting plates, I used cutting oil for the Cobalt bit, I tried the water/oil mister, and it controlled the heat way better. I'll have to see where the spindle is grabbing the arbors, it is difficult to get arbors in or out now.


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## markba633csi (Jun 5, 2021)

I suspect the speed is too high especially for the larger cutter


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## MrWhoopee (Jun 5, 2021)

markba633csi said:


> I suspect the speed is too high especially for the larger cutter


I was going to say the same. I generally use 1/2 the cutting speed of CRS for 304 and 316, putting it at 40-50 sfpm. This gives a speed of about 100 rpm for the 2 in. cutter. I might push the speeds a little higher with a drill, which I can sharpen myself. I have seen some surprisingly high cutting speeds listed in some of the charts online. I have no idea where they got them.


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## Video_man (Jun 5, 2021)

The chart that came with my annular cutters says 20 to 40 sfm depending on how hard the stainless is.  Their chart gives 2 inch cutter, then, at 38 to 76 rpm.  HTH.    <edit>  Here is a link: https://www.icscuttingtools.com/pdfs/Feeds-Speeds-Annular-Cutters.pdf


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## Aukai (Jun 5, 2021)

The 2" cutter I ran at 245, and it cut better with a ton of coolant. I did not find a chart in my hunt online for annular cutters. The 1/2" was another Fein that cracked. I guess I dodged a bullet with the 2" using that much RPM....


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## markba633csi (Jun 5, 2021)

The charts are for production, I think, where tool life is not the highest priority. For hobby use time is not as important


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## AGCB97 (Jun 5, 2021)

I always run annular cutters in my Bridgeport at the slowest speed in back gear w/ spray coolant. They cut fast and clean and smooth. I've never damaged one. I have not tried SS.
Aaron


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## aliva (Jun 6, 2021)

Regardless of the size of cutter I run max of 450 rpm with plenty of cutting oil. Use aggressive to be sure your not rubbing. If its producing long string chips your good to go. Hougen drills run at 450 rpm







						Hougen HMD904 Portable Magnetic Drill
					

The HMD904 is the drill of choice for steel fabricators. A lightweight magnetic drill with a powerful Hougen motor makes it the perfect drill for steel fabrication. A Swivel base model is also availble.



					hougen.com


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## Aukai (Jun 6, 2021)

Thank you, with the 2" cutter I was getting the long stringy "brillo" pad swarf, when I was using the 1/2" it was producing tight curls like a drill bit, then snapped. I have broken other Slugger ACs also, but not other brands. I'm too early in my experience level to blame the tool. My mag drill is an Evolution 28 570 RPM.......


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## mksj (Jun 6, 2021)

I was always told to never exceed 400 RPM with annular cutters, might be able to push a bit higher in aluminum and some WD40. At 2" probably would want to be in the 200 RPM or slightly lower. Constant pressure to form strings coming off not pecking. Issue with SS is as you are aware work hardens, although I have not had any problems machining 316 with sharp cutters. It may be the cutting teeth of the annular cutter that you need enough pressure and low enough speed (with lube) so you do not get chatter. I used a 1.5" annular cutter to through bore some 2.5" 4140 from both ends for a spider, it went very smoothly and if I recall I was at something like 220 RPM.


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## Aukai (Jun 6, 2021)

Thanks Mark, I'll try slowing it down some more,,,,next time


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