Carbide Tools

A little bit ago, I asked some questions about carbide inserts for wood turning and got some helpful replies. I bought a round, square with radius and a diamond detail insert from AZ Carbide and they were not very expensive.

I mounted these to 3/8" and 1/2" square steel bars by filing the end of the bar down to receive the insert. It was difficult to get the area flat. So, I used my Dremel tool set up like a router with a grinding stone. I held the bars down and then gradually ground the surface down flat. Surprisingly, it worked very well. The inserts required 4-40 and 6-32 tapped holes. The small 4-40 was difficult as I had not tapped a hole in awhile and this was a small tap. After tapping the holes, I shaped the nose of the bars to correspond to the carbide insert mounted on it.

I had some ash and prepared blanks by routing a groove into them and then gluing them together to give a snug fitting square hole. The bars are held in by a 6-32 machine screw through the handle and into the bars. The ferrules are copper end caps that were polished. The finish on the ash was a dark Danish Oil and wipe on poly.

Attachment 342730

I am really pleased with the way these cut and they stay sharp and especially happy with the low cost to make these compared to buying the handles.

I've seen the azcarbide brand around for a while now. While I've predominantly switched to traditional tools I still occasionally break out my EWTs for small tasks. Do you or anyone else know how azcarbide cutters compare to the EWT line? Thanks

I'm using carbide cutters less and less but I have (and continue) to get my replacement cutters from AZCarbide. I certainly don't have any specs or technical information, but I don't know that I would be able to tell the difference between their cutters and those from EWT. AZCarbide will continue to get my business.

Larry, you did a very nice job on your tools. Like you, I enjoy making some of my tools.

I've made about a half dozen carbide tools and usually use AZ Carbide (as you do). I use primarily classic tools for a lot of my turning as they usually are able to produce a nicer finish. But I use the carbide for some specialty applications.

My favorite - - I have one that takes 0.4" square carbide cutters (the ones that cost around 3 or 4 bucks each and are intended for a rotary planer). I like it for doing roughing cuts/hogging out. I also use a carbide detailer for putting rings on the foot of my turnings.

I also use a round 1/2" carbide scraper inside of hollow forms. I periodically touch it up by grinding the top of it. It helps but it doesn't cut as nice as when new.

One of my next projects is to make a HSS round scraper insert to fit on the end of one of my carbide-tool handles. The plan is to make an insert similar to a carbide insert but one that can easily be resharpened on a moments notice. Brand-new fresh carbide scrapes pretty nicely, but it doesn't stay that sharp forever. I find that a sharp scraper with a fresh burr produces really nice cuts. I might also make a negative-rack HSS insert.

I made a special steel insert for cutting or re-cutting dovetail tenons and mortises. I made it small enough that I can keep the tailstock in place and slip it into the mortise/pocket to make it round again. It works really slick and makes it so easy to re-cut a pocket that is no longer round (after drying and shrinking).

I'm also planning on making a couple of of positive rake carbide cutters that are angled downward to reduce their aggressiveness.

Right now I'm using old filles for the source of some of my homemade tools and inserts. That is also what I'll use for some of my re-sharpenable inserts. I take out the hardness to shape them and then reharden and anneal them for use. It is actually very easy to do. They come out hard enough that they don't need excessive resharpening from use. Eventually, I will probably buy either some tool steel or buy some sacrificial planer blades that will also serve the purpose.

It is nice to find another wood turner who likes to make his own tools.

I like and appreciate custom made tools and looks like you have done a fine job. Thanks for sharing.

Thanks as well for the tip on AZ Carbide. I have seen them but will now look deeper. I hoping to make some hollowing tools and needs some inserts so that is a good lead.

Looking at AZ Carbide's site could be a little confusing for noobs to carbide.

Most of their inserts are flat top, neutral rake. These would basically be scrapers. Not something I would use for general turning.

In round inserts they show inserts listed as "shear" as replacement for Hunter inserts. These are cutting inserts not scrapers. In carbide nomenclature those would be "high positive". They're free cutting inserts which should leave a surface needing little sanding. But, in a quick look at their offerings makes me wonder why I don't see high positives in other shapes.

Things can get more confusing. Inserts used in planer and shaper cutter heads are flat top, but the way they're oriented in the cutter heads makes them high positive shear cutting.

Thanks for the description Doug. Yes, the flat tops are scrapers not cutters. The scrapers can cause tear out and tear out hampers the finish as we all know.

For hollowing tools I will use the cutter (dished) types. As you have pointed out, the Hunter tools use them and there are fine examples of hollowing tools made using them. For example the Trent Bosch articulated hollowing tools with carbide are examples of this.

If you are tool maker, you can make many the shapes that you might want. The trick is to have enough grinding and machining capacity to do so.

Just fyi, there are some carbide cutters out that with a designation RNMG that will also work as a cutter but I believe the ones that AC Carbide sells are likely more flexible in terms of size and in their application for cutting wood.

I personally am in the midst of putting together a 2 hp variable speed belt grinder to augment my shop's kit to handle this kind of work much easier.

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Originally Posted by Larry Frank

A little bit ago, I asked some questions about carbide inserts for wood turning and got some helpful replies. I bought a round, square with radius and a diamond detail insert from AZ Carbide and they were not very expensive.

I mounted these to 3/8" and 1/2" square steel bars . . . . . .

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Larry,
Curious to what kind of steel you used for the bars? Any insights as to what is necessary there would be appreciated.

Alan, I've made a bunch of lathe tools. I usually pick up the steel at a steel yard. A few times I've picked up a 30" or 36" length at Home Depot but it costs about 3X what I pay at the steel yard. For the bars, I like cold-roll steel if I can find it. It is shiny and easily machined. I typically buy 1/2" square or round stock but also pick up bigger pieces if I'm making a tool with a longer reach. If I can't find cold roll steel, I'll buy hot-roll which is always available. It is a dark gray color on the outside due to the original hot processing which caused some oxidation. Sometimes I'll leave the surface as they come (dark gray/black) but I will sometimes take a file or belt sander to them to shine them up and making them smooth where they'll contact the tool rest. But the inside is basically the same as the cold roll, although cold roll will be slightly harder due to what is called "work hardening". But the difference isn't something that you would ever notice. Typical hot-roll and cold-roll is mild/low carbon 1018 steel. But at many metal yards, the workers will give you the "deer in the headlights" look if you ask for 1018. I've made enough tools that I usually buy a 10 foot stick of the metal and pay around 60 cents a pound. I've also bought a 20 foot stick.

If I'm making something extra special that required more machining, I will order what is called "free machining steel" off of ebay or on-line. It has a designation of 12L14. It machines beautifully and cuts and threads like butter. It is slightly stronger than garden variety 1018 but doesn't weld very well. I suppose that it could be brazed or silver soldered if needed. It costs more than garden variety 1018 and I usually find it in shorter lengths. Plus there is a shipping charge. So I usually just use the 1018.