Carbide inserts for hollowing tools?

[Alan Heffernan]

I am going to make some carbide tipped hollowing tools.

I have a complete metal working machine shop (lathe, mill, knife/belt grinder, drill press, saws, TIG and MIG welders, plasma cutter, tooling, . . . . ) I plan on buying some heat treatable stock and making my own straight and goose necks to then be used in a hollowing system. I've bought a lot of carbide inserts for my metal working tools but just now stepping into the wood turning insert world.

I have done some searching already but thought I would seek the latest insights here for decent sources of carbide inserts and screws for wood turning/hollowing. Any advice would be much appreciated.

[Kyle Iwamoto]

If you're capable of making your own tooling, my $0.02 is Hunter carbides, hands down. First off, I am not a carbide fan, but for hollowing, I use them, and by far the Hunters are my favorites.

[Alex Zeller]

I think heat treating would be overkill. I'm not a big fan of carbide but I do have a couple Hunter tools and a couple clones. The main carbide tool I use is the Hunter osprey tool. The way it's used means there's almost no force at all on it. I have toyed with the idea of making tools to hold that style carbide cutter in different swan neck shapes. But I haven't had a chance to try making any hollow forms yet. The only other carbide tool I have is one that's diamond shape. I haven't tried any of the flat/ curved scraper style ones.

[Richard Coers]

I'd go so far as to say a hardened shaft on a turning tool could be dangerous. If the annealing wasn't done well, the shaft could snap with a bad catch. Pay attention to what others are doing with Hunter style cutters. Hardly anyone keeps it flat. Usually it's tiled down and also an angle to the side. It can get real grabby if presented straight into the work in a traditional style scraping cut. If you use a flat carbide insert, don't use anything designed for steel. They don't have enough relief and are not honed to be sharp enough. Don't use anything over 6mm. Large cutters are also hard to control hidden inside a vessel.

[John K Jordan]

I am going to make some carbide tipped hollowing tools.
... I plan on buying some heat treatable stock and making my own straight and goose necks to then be used in a hollowing system. I've bought a lot of carbide inserts for my metal working tools but just now stepping into the wood turning insert world.
I have done some searching already but thought I would seek the latest insights here for decent sources of carbide inserts and screws for wood turning/hollowing. Any advice would be much appreciated.


Hi Alan!

I second the thoughts of those who say the Hunter carbide cutters are good. I bought and tried various carbide tipped lathe tools and I'm not yet impressed with the quality of the cut. The Hunter tools are in a different class.

I also wondered about the need to heat treat the shafts. I think making them from either mild steel or some machinable alloy should be fine for hollowing and other turning.

I really like Mike Hunter's straight and swan necked tools that have tapered shafts such as this one: http://huntertoolsystems.com/product/5-full-swan-neck-tool/. The cutters are small and remove wood with little force and the taper provides strength and vibration resistance as well as a smaller diameter at the working end to get into tighter places. If making tools from scratch I'd probably turn a taper on a rod then heat and bend. If heat treating you might anneal for toughness instead of hardness.

As for cutters and screws, you can buy them from Hunter. He even sells the cutters, bits, and a short shaft with a machined pocket and threaded hole for the cutter:
http://huntertoolsystems.com/product-category/retrofit/

JKJ

[Peter Blair]

I'm not certain that there is any if much difference between the quality of carbide sold today by US suppliers and my favourite is AZCarbide. Price point is great and Ron Campbell is a treat to work with!

[William C Rogers]

I like AZcarbides also, but haven't tried the Hunter. The carbide cutters that came with my Hope hollowing system are also very good.

[Steve Estabrooks]

If you have a machine shop and use carbide cutters, you may want to try metal cutting inserts to cut wood. I had some high feed milling inserts, both round and square that were used for metal cutting. Out of the box they dont cut wood at all. I took the inserts on a flat diamond stone and took a half a dozen swipes on the stone, and now the inserts cut wood like butter.

[Brice Rogers]

Alan, I have a similarly equipped machine shop.

I have made a half dozen carbide tools. I typically have bought my carbides from AZ carbide. But I also bought a couple dozen 0.4x0.4" square cutters intended for a jointer/planer @ about $2 each on ebay. Eddie Casteline also sells a variety of cutters at reasonable costs.

My most sophisticated carbide tool is my own version of the Hunter Hercules tool.

I also have a few tools that use high-carbon steel inserts that I have hardened. I have taken old files (good source of high-carbon steel), annealed them to a soft state, shaped them and drilled a hole and then re-hardened them. Some I will also temper to make less brittle. I also have a couple of tools that I've made from M2 tool steel. It helps to have an electric kiln and a toaster oven for heat treating.

I use those tools for specialty purposes but I my primary tools are conventional tools like gouges, scrapers, NRS, etc.

[Peter Blair]

Steve any chance of a photo and can you please clarify exactly what you did with your diamond stone? Did you swipe the top or the cutting edge or ???

If you have a machine shop and use carbide cutters, you may want to try metal cutting inserts to cut wood. I had some high feed milling inserts, both round and square that were used for metal cutting. Out of the box they dont cut wood at all. I took the inserts on a flat diamond stone and took a half a dozen swipes on the stone, and now the inserts cut wood like butter.

[Russell Nugent]

I've talked to a few guys who use recycled metal turning bits. They hone the top to sharpen it.

[Peter Blair]

Russel are you talking about carbide inserts or other steel metal lathe bits? The inserts I see most for metal have a small edge and a sort of 'trough' next to the edge. I think they might be ruined by honing the top but I've been wrong lots of times before!!! LOL!!

I've talked to a few guys who use recycled metal turning bits. They hone the top to sharpen it.

[Russell Nugent]

The inserts. I haven't tried it with them myself. It apparently works because the top of the cutter doesn't matter. The cutting is done by the carbide on the front edge.

[Peter Blair]

Interesting, I guess I'll have to give it a try but not too sure yet if I'll try honing.


The inserts. I haven't tried it with them myself. It apparently works because the top of the cutter doesn't matter. The cutting is done by the carbide on the front edge.

[Tom Giacomo]

For several years I have been using Captain Eddie Castelin's carbide inserts. He has a good selection and very good prices. Also he has round inserts in several sizes which are hard to find sometimes. You do sharpen them by honing the top. The ones with the trough are for metal cutting.

[Steve Estabrooks]

Pete,
All I did was lay the insert flat on the stone, topside down on the stone and a few swipes on the stone. I did not touch the sides. You should be able to feel the insert is sharp. All it does is take the factory honed edge off so there is a sharp edge. A lot of the metal carbide tools they break the cutting edge a little to make stand up to the stresses of cutting metal.
Steve

[Bill Jobe]

You do sharpen them by honing the top. The ones with the trough are for metal cutting.

The trough I believe is for chip breaking. May also allow more coolant direct contact with cutting edge.

Just curious, anyone try turning wood with ceramic tips?

[Peter Blair]

Thanks Steve I asked the question because most of my metal cutting carbide bits have a little 'river' next to the edge and it would seem to me that if I did as you suggest it would flatten off the cutting edge and the cutting edge on my wood carbide cutters are SHARP!

[John K Jordan]

Thanks Steve I asked the question because most of my metal cutting carbide bits have a little 'river' next to the edge and it would seem to me that if I did as you suggest it would flatten off the cutting edge and the cutting edge on my wood carbide cutters are SHARP!

The only ceramic and carbide bits I've successfully sharpened were flat on the top. I have a number of 3"x8" diamond plates up to 1200 grit which are perfect for this.

I mostly use them to sharpen expensive ceramic cutters for shearing the llamas and alpacas. (the companies that sell the cutters say they can't be sharpened.)

JKJ

[Peter Blair]

Thanks for the information John. So often we hear what can and can't be resharpened but often the makes don't realize just how resourceful we turners can be!