Gouge breaks in half. This happen to anyone?

Re: Gouge breaks in half.  This happen to anyone?

Dave Paine

Wow, I have not seen such a break like that on a bowl gouge. A lot of steel in the 5/8in dia even after the flute is ground.

It was likely made as well as designed by Crown.

I am interested in other replies.

Perhaps the surface hardening went a lot deeper than intended.

I would expect that the majority of catches would insert more force on the tool than just hitting a concrete floor from waist height.

Re: Gouge breaks in half.  This happen to anyone?

John K Jordan

Yikes. I haven't seen that and I've dropped plenty of tools before I built my unpatented NeverDropAGougeAgain tray for my lathe.

I would love to know if our hardened tools are really that brittle or if it is a factory defect. If they won't replace it I would probably try heli-arc welding it. That would reduce the useful length but a good heat sink might minimize the area of temper damage.

Re: Gouge breaks in half.  This happen to anyone?

Alan Hollar

It is fairly rare but it happens. The gouges are hardened all the way through, not just on the surface. Surface hardening would disappear after a grinding or two. Think about the actual location of the sharpened edges of a bowl gouge. Little of the edge is actually on the original surface. Could be over hardened, could be an internal defect in the stock.

Re: Gouge breaks in half.  This happen to anyone?

Brian Mcinturff

My guess is inferior steel and already had some microscopic fractures in it. Might be able to look at the broken ends under a microscope and be able to see if it was inferior.

Actually happened to me this year

Dick Coers

So once in 27 years. I clipped the Oneway big bite center with a bowl gouge. Just barely marked the cutting edge, and little more mark in the big bite, but the gouge broke into 4 pieces. I called the manufacturer, sent them a picture, and they sent me a new one.

Yes it does happen....

Ralph Lindberg

Notice the back end of the gouge, note that it is solid, ie no hole drilled through the shank.

That's a tell tale sign about how the tool was heat treated.

For the hardening phase, it might have been passed through and induction heater coil, with the butt end of the tool being held.

For the tempering phase it was probably put in a basket and the entire basket was tempered at once, or once again passed through an induction heater, while held at the butt.

These can, and do, sometimes combine to cause some uneven tempering of the tool. Or why so many tools are not "hard" or are too "hard" up around where the flute ends.

Some of the best tools have holes drilled near the butt, this allows the tool blank to be fully suspended for the heat treat process. With minimal contact with other tools and mounts. This can result in a more even heat treatment.

I've seen several ....

Geoff Whaling

some actually in use at the time. Usually poor tool presentation where the tool engages the spinning wood with the tool on the tool rest then impacting the tool rest is the prime cause; or a prior event has initiated the failure point.

I've also seen several spindle roughing gouges and bowl gouges with signs of cracks, particularly SRG's with damaged tangs.

As others have mentioned, the desirable properties of a "good tool" means that designers have to balance the known characteristics of the steels alloy, machining, hardening, tempering, annealing against wear, brittleness, fragility etc.

An oversight in the manufacturing process, and poor quality control, can mean that even reliable manufacturers can occasionally get it wrong.

Re: Gouge breaks in half.  This happen to anyone? 

Jon Ogata

Additional information on my gouge that broke from a fall off my lathe bed. This is a close up of the gouge showing the failure or break.

break.

Re: Gouge breaks in half.  This happen to anyone?

Barry Irby

I had a Hinkel Chef's Knife that I laid on it's side and smashed a glove of garlic. About two inches of the tip flew off. I returned it and they gave me a new one. An up graded newer version. Never broke a gouge though.

Re: I've seen several ....

Sean Troy

Even a diamond can break if hit correctly.

That appears to be a very clean break, .....

JamieDonaldson

...suggesting a failure in the hardening or tempering process rather than a defect in the steel blank.

Re: Gouge breaks in half.  This happen to anyone?

david

My wife did that with a ceramic knife. Now she knows better after the blade ended in two pieces.

It was quite a surprise.....

Barry Irby

I really did not hit it that hard and the blade broke at a point that was not being stressed, at least the garlic was several inches from the break. Must have been a defect in the blade. I had owned the knife for maybe twenty years. I like the new one, but I miss the older one. I bought it when the cost of it was a significant investment and it was an old friend.

Re: I've seen several ....

Geoff Whaling

oops should say without the tool on the tool rest

Take a file

steven antonucci

See if you can scratch the surface of the gouge (now that it is scrap, anyway) on either side of the break. My guess is that one side is hard, and the other is not... and the induction heating theory is correct. If you watch "How It's Made" you can see how quickly the coils bring the steel up to temperature, but it certainly isn't the best method because most steel requires a few minutes at critical temperature for the best result.

Jon's picture with the dark spot at the top of the flute is probably a stress crack. I wouldn't be surprised if you had a dark spot either?

Steve

Re: Gouge breaks in half.  Making lemonade

Joe Fleming

After you are done with all of your analysis, if you get to keep the gouge, grind reference grinds on the three fluted ends to use as sharpening aids. This is what I do with my used up gouges. Joe

Excellent photos

Don Orr

That could easily be the fracture propagation point meaning there was a small crack or defect in the original steel bar. If the gouge landed at an angle in just the right position (which it obviously did) then a complete fracture is no surprise. It doesn't take much to break a piece of steel or other strong material with a defect present. Think of how we break down the 3/16" HSS cutters for our hollowing tools-cut it part way through and snap it off. Same concept. Fortunately this failed while not engaged in a large rotating piece of wood and you were not hurt. I'll bet DE or Crown will replace this and maybe even want it back for analysis-I would. Major bummer though.

Handle broke

Jorge

I had a scary incident a couple years ago, I was turning end grain bowls and had a big cylinder on the lathe, I was halving it, a 1/2" square bedan made from a Crown round tip scraper, endless ribbon was flying away, everything running very smooth, then of a sudden, the handle left my hand and I heard the steel hit somewhere behind me.

There was no catch, no slamming, just poof, gone! I did not get hurt and did not have time to get scared

I found a piece of the broken handle in the other side of the lathe and the other behind me, it took me two days to find the steel, deeply embedded in a piece of 3/4" plywood, then I realized that if that steel have had hit me I was to be in a very sad shape.

No flaw of the steel, the beech handle was what broke.

I still have not given it a handle...

Re: Gouge breaks in half.  This happen to anyone?

Dale Gillaspy

The only other thing I have seen even remotely close to this was under a lot of pressure. In 1997 I was working trying to rescue someone involved in a serious car crash. My partner and I were working on the victim, while Ladder Truck guys were using the jaws of life to cut the "A" post on the car. As they released the jaws, something gave way (We figured it had to be a hidden defect) and one of the jaws of life flew across the car and hit my partner in the forehead. (He had taken off his helmet to get better access to the patient. In hindsight, this wasn't a good choice.) Luckily, the flat part of the jaw hit him and not the sharp part, or it would have killed him. Engineers and Metallurgists from the Hurst Tool Corporation could not fully confirm what caused it, but they figured it was a hidden defect in the steel that was never detected. BTW, that tool had been used for years, inspected on a regular basis, and never had a problem.

Re: Gouge breaks in half.  This happen to anyone?

Jon Ogata

Followup on my broken bowl gouge. I called the seller who contacted the manufacturer. In less than 24 hrs, I received an email saying the manufacturer would replace the gouge under warranty.

Thanks to all of you who provided comments and especially to David who started the discussion and Alan Hollar who did all the work of contacting the manufacturer.

Mahalo and Aloha,

Jon

member of the Honolulu Woodturners, a chapter of AAW

Re: Gouge breaks in half.  This happen to anyone?

Robert Lalonde

My brother in law is a professional metal worker, Here are his comments.

My thought would be an improper heat treat or anneal that created some brittle metallurgy right smack dab where it "shattered". M2 has lots of carbon so it will harden when heat treated but there has to be an annealing process to reach the desired hardness PLUS create a transition from that 'hard' to a not so hard area so you don't get 'snap-osis' Even the best toolmakers mess up once in awhile.