large washers

I want to buy/make some large washers in 3mm stainless, about 85mm OD and 30-75 mm ID.
Any suggestions as to how to go about it? I was thinking boring head in
a mill, but that would be a right pain. Do they make end-on cutters for boring heads?
Can't think of a lathe method.
Help?
Peter Fairbrother
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On 02/12/16 11:12, Peter Fairbrother wrote:

Peter,
Depending on the quantity you require I would say consider getting
If you want to stay local the I understand CAM Engineering in Trowbridge do water jet cutting but no idea of their prices. I have heard of some cheaper places for laser cutting in Bristol but don't have any names at the moment.
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If you need enough to use 500mm of stock, item 252633149437 on ebay.co.uk is 316 stainless round bar with a suitable diameter.
you'd want to turn the OD down, bore the ID, then part off the washers as you went.
If cutting from plate on the mill, you could do worse than getting a couple of hole saws of appropriate diameters and cutting the ID, followed by boring to size, then cutting the OD and turning that to size after mounting the washer on the outside of a 3-jaw chuck on the lathe.
If going down that route, drill a couple of holes hanging out to the scrap side of each hole saw's path. That gives the chips a chance to clear themselves from the saw and makes it cut properly.
You can grind a trepanning tool for a boring head. Start with a round blank, remove half the diameter so the cutting width is on the diameter. Grind a bit of relief on the bottom and off you go. Mounting a bit of 1/8" round HSS in a 1/2" round carrier can be better than doing it all with a 1/2" round HSS blank!
Have fun.
Mark Rand
--
RTFM

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On 03/12/16 22:57, Mark Rand wrote:

Tried that, with medium-grade holesaws, bimetalHSS. No go, they got blunt.
Expensive bimetals, very noisy, need hearing protection. Maybe I'm doing something wrong ...
Any recommendations for holesaws for stainless?

Trying that now, using the 1/8 shank of a broken carbide drill in a purpose-made holder. It makes a round groove, of sorts ..
-- Peter F

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wrote:

What speed were you running at. you need a lot of pressure and no more than 60rpm for 85mm in stainless. Clearance holes for the chip also a very good idea.
regards Mark
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On 19/12/16 14:46, Mark Rand wrote:

You can get diamond-encrusted holesaws now - they're not enormously expensive and they tend not to wear out...
--
Rusty Hinge
To err is human. To really foul things up requires a computer and the BOFH.
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On 02/12/16 11:12, Peter Fairbrother wrote:

Search on 'mudguard washers'?
--
Rusty Hinge
To err is human. To really foul things up requires a computer and the BOFH.
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