Is it cap iron or is it chipbreaker?

Re: Is it cap iron or is it chipbreaker?

Bill Tindall, E.Tn.

Someone influential in my life preached that if you spoke accurately it would promote thinking accurately. To that end he disliked names that misled the function. I proposed tongue in cheek once on that other forum the term "shaving bender". The response to this suggestion suggested a lack of humor among the hand tool enthusiasts.

I don't like either name as neither reveals the function.

Re: Is it cap iron or is it chipbreaker?

Wiley Horne

Frank Bailey used ‘cap-iron’ in his 1867 patent application, where he was seeking a patent for the hump at the lower end.

Of course this came 100 years or so after the invention of the double iron, so surely there is a predecessor term.

Wiley

Re: Is it cap iron or is it chipbreaker?

CJ in MPLS

While I agree with your preference for descriptive terminology, I have to say as a patent attorney that it is damned hard to come up with such descriptive terms for an entirely new thing. We are permitted, you see, to be our own lexicographers.

Mostly we use whatever terms the engineers used.

All of this is to say that it could have been much worse.

Yes

Joe shelton

Your title uses cap iron before chip breaker, and that is OK with me.

My preference is to use a term other than "thingee" because I prefer not to sound frivolous or ignorant.

I'll know what you're referring to with either usage. I will not be didactic about usage if you choose a form other than my own choice.

I like conventions, fairly often. I think they are idiomatic and colorful, and they keep me from being completely dour. We all know what a person means by saying "I could care less." We all know what you're talking about when you refer to a chip breaker.

It is not taxonomy. It's conversation. Now, coffee break is over. Everyone back in the shop.

Smith’s Key, in 1816

Wiley Horne

calls it a ‘top iron’. A more expensive version has a nut brazed on, and it is sold as ‘top iron with solid nut’.

Wiley

No

Derek Cohen (in Perth, Australia)

Your title uses cap iron before chip breaker, and that is OK with me.

Joe, in fact I have to date preferred "chipbreaker" simply because it is factually more correct (bending/breaking shavings) than "cap iron" (supporting the blade).

I did wonder how this was referred to when first used for the specific purpose of controlling tearout? Also, was there a difference in the UK versus the Americas?

Regards from Perth

Derek

Re: Sub Blade?

TomD

To me, cap iron sounds more like the function that is associated with this item where it controls blade position. Of course, more pedantically that might be something that actually said it's function was supposed to be getting a hold on the iron so that it could be manipulated by a screw for depth or tilt.

Cap Iron also sounds more like the function of the part as it is intended to stiffen the blade, for those so inclined.

Breaker is entirely accurate as the shaving is broken to control the shape and exit of the shaving. Since the majority of planing had nothing to do with the final surface of the board, the functional description is not necessarily going to refer to that function that is of little importance in most work.

When my daughter was young she thought that the plane's purpose was to make shavings. The shavings are so much more an obvious outcome than the thou that came off the stock. Packaging shavings is a reasonable objective, since one ends up with lots of them. You don't need them tangling everything up , or being hard to get into the stove. Metal working tools are specifically formed to make the shaving more manageable, disposable and safe. At least the safety of shavings is not an issue in our work, for the most part.

Japanese tool catalogs use the sub blade designation as it is more descriptive in their use.

Of course a practical use for technical language is that it keeps the meaning with the guild or group that control the craft. This is redundant in something relatively simple, and as well distributed as woodworking. But even in woodworking it was alive and well until relatively recently.

Re: Sub Blade?

David Weaver

There are certainly advocates of single iron planes being better or higher quality, but I've never seen anyone who has prepared 500 feet of rough lumber who would think of saying any such thing.

Re: Is it cap iron or is it chipbreaker?

William Duffield

I can't help with epistomology, or ancient lexicological history. FWIW, I have found early 20th Century Stanley documenation calling it a chip breaker. Due to functionality, that is the term I prefer, especiallly since the elastic limit at which the chip starts breaking instead of curling is the clearly visible indication that you shouldn't adjust it any closer to the blade edge (at those angles and for that particular piece of wood). That of course, would suggest it should be called "don't break the chip!" or something more descriptive

Another advantage of using the term chip breaker is that neophytes are more likely to ask you why it is called that, and you can proceed to enlighten them. Maybe they'll even listen, if they haven't already been brainwashed. Otherwise, they are likely to make up all sorts of effort-wasting theories about why it is called a cap iron, and how you can fiddle with all sorts of arcane parameters to improve tearout response. Those exercises in futility will of course lead the neophyte to alternative fora, blogs, gurus, youtubers and self-proclaimed experts who will totally fog up their enlightenment.

Of course, on WoodCentral, we understand and can use either term interchangeably, or when discussing among ourselves, can use the code word "double iron" (even when we know it is really made of steel).

References

Winston

I think you're referring to Steve Voigt's article in Mortise and Tenon #6. He's done a lot of research into this. Here are some of the references from there, and from his blog:

http://blackdogswoodshop.blogspot.com/2016/03/the-double-iron-part-1.html

https://blackdogswoodshop.blogspot.com/2016/07/the-double-iron-part-ii.html

The earliest is in an advertisement by Carruthers (1767), where he calls it a "double-iron plane."

Salivet (1796) calls it "rabot a deux fers", which translates to "plane with two irons." These two don't seem to have a name specifically for the upper blade.

Nicholson (1846) calls it a "cover": "a cover is used with a reversed basil" (where "basil" means "bevel".

Holtzappfel (1846): "the top iron more effectually breaks the shavings, and is thence sometimes called the break iron."

Lukin (1879): "The break iron of the jack planes is generally fixed"

Young (1882): "the edge of the break iron"

Denning (1891): "the edge of the back iron"

Hayward (first half of 1900's, not sure exactly when): "After sharpening the plane iron, the cap or back iron is replaced..."

Usage over time

Winston

The Google Books Ngram viewer can make a graph of usage over time:

I also tried adding "back iron" and "break iron" to the search, but when I looked at the books where those terms come up, I saw that they were also used for things besides woodworking tools.

Along the same lines, many of the 20th century uses of "chipbreaker" are from metalworking.

https://books.google.com/ngrams/graph?content=chipbreaker%2Ccap+iron&year_start=1800&year_end=2019&corpus=26&smoothing=3&direct_url=t1%3B%2Cchipbreaker%3B%2Cc0%3B.t1%3B%2Ccap%20iron%3B%2Cc0#t1%3B%2Cchipbreaker%3B%2Cc0%3B.t1%3B%2Ccap%20iron%3B%2Cc0

Re: Usage over time

Eric Rathhaus

Thanks, Winston. I luv this use of google.

Re: Is it cap iron or is it chipbreaker?

Warren in Lancaster, PA

The term chip breaker had two other uses before it was used for a double iron.

Starting in the 1880s it was used for a plate screwed to a "planing machine" to improve machining. It still has this use today. It was also used to describe a plate or a ridge on a tool for turning metal to break the chip so you would not end up with a long strip of iron or steel that would tangle up. Machinists use the term chip where we would use shaving. I don't know which of these uses was first.

Here is the current definition of chip breaker in Merriam Webster:

: a shoulder in a machine tool made by grinding a groove parallel to the cutting edge or by attaching a plate to the top to form a wall against which the chip produced in turning or other machining will be broken up

I well remember the first time I heard the term chip breaker, about 40 years ago. I visited a friend whom I had thought expert in hand planes. He said "The term chip breaker is a misnomer because it is really just a blade stiffener." I was so shocked I did not know what to say.

"Cap iron" has a longer time of usage, and older terms than that have generally gone out of usage.

Re: Is it cap iron or is it chipbreaker?

Bill Tindall

The manual for my industrial strength thickness planer calls the heavy steel surface that rides the wood surface just in front of the cutter head a "chip breaker". It is set to ride below the cutting circle so as to add its hinged weight, which is substantial, to the wood surface ahead of shaving formation. Frankly I have not seen that it does anything to mitigate tear out. It can get bindy and impede feed. It connects to a manual lever so it can be raised if it binds the feed.

It seems odd to call this power planer feature, as well as a hand plane "cap iron", both a chip breaker. Wonder where hand plane "chip breaker" derived from and which use of the term came first?

Re: Yes

Sgian Dubh

We all know what a person means by saying "I could care less."

Joe, that expression usually makes me chuckle and ponder a bit because to my British ears it sounds like you're saying you quite like or are positively in favour of whatever the subject is that's being discussed. In other words, if you didn't like it as much as you do you could care less. It's not an expression I'd ever use because I'd say I 'couldn't care less'; in other words I don't give a rat's ass about it, which is what I always assume is meant when a North American says they 'could care less'.

Anyway, cap irons and chipbreakers. When I started fooling around with woodworking tools in the mid to late 1960s the term was cap iron. I don't recall ever hearing an alternative name for it until I came across the term chipbreaker either here at WoodCentral, or possibly an American woodworking magazine. It took me a little while to puzzle out that a chipbreaker is what I knew as a cap iron.

I'm not arguing the historical or even current merits of one term over the other, nor am I proposing that other alternative terms are better or worse - they all seem to have been used, and are still in use to a greater or lesser extent, and as long as people understand what's meant by any one, or all of those terms, I guess that's all that matters. Slainte.

A good design...

David Weaver

..of chipbreaker on a jointer or thickness planer is probably good enough to say that the modern carbide inserts are kind of a waste of time.

I recall Brian Holcombe mentioning that he picked a tersa head over a spiral head and that when it's set right, it controls tearout very well.

A lot of the portable thickness planers are fairly limited in cut depth and have their top knife set reasonably close to the cutting edge (no reason for them to sit back further as they couldn't handle a big cut), and do very well to limit tearout.

I don't know a lot about the various designs of heads in large stationary machines, but do know that my woodworking buddy's inability to understand why his DC580 blades would be set a certain way led to spectacular tearout (I didn't know enough at the time, either) and his fix was to buy spiral heads (one for his jointer at the same time). I think if he'd have known how to set his machine, he probably wouldn't have needed to make those purchases, and I'm sure the manual said something about it, but if nobody ever talks about how a top knife on a planer holds chips down, it may go over the head of the person reading.

Same thing took out my first planer, though - I had a portable delta that had a mild steel top knife, some material got under it, bent it, and the part was NLA (a delta specialty) and out it went to the trash pile. I couldn't get it back straight enough that it didn't just jam right away again.

Re: Yes

Joe shelton

Ah, Rich, we're good examples of Bernard Shaw's quandary: The British and Americans are two great peoples divided by the same language.

Our only outlet from this impasse is for Derek to weigh in from that third great people, and either tip the scale or sever the Gordian knot.

I can live with that - I've been studying pastoral philosophy by watching Hamish MacBeth.

Re: Yes

Derek Cohen (in Perth, Australia)

Ah, Rich, we're good examples of Bernard Shaw's quandary: The British and Americans are two great peoples divided by the same language.

Our only outlet from this impasse is for Derek to weigh in from that third great people, and either tip the scale or sever the Gordian knot.

I can live with that - I've been studying pastoral philosophy by watching Hamish MacBeth.

Joe, there is no third option. Australian craftsmen were largely of British extraction, as were my grandparents and back - so I am biased towards rebates and housings, but am aware I have to talk down here, so it becomes rabbets and dados (ducking and weaving) .

Regards from Perth

Derek

Re: Yes *LINK*

William Duffield

A dance festival in Amsterdam?

The American idiom, from the '50s, was "cut the rug"

Maybe what are needed are sharpened carbide taps? They might make an effective replacement for floor scrapers, which were discussed in another recent thread. They might even be patentable


Paint Scraper…Mill Marks

Re: Yes

William Duffield

That's one small advantage of globalization. Google tells me the nearest to me (an Argentine tango school) is only 50 miles away. I couldn't get there before they close this evening.

Rabbets

Warren in Lancaster, PA

Australian craftsmen were largely of British extraction, as were my grandparents and back - so I am biased towards rebates and housings, but am aware I have to talk down here, so it becomes rabbets and dados

Rebate is a corruption of rabbet. The traditional English term was rabbet, and was used in the 18th century and into the 19th century. We have used rabbet since the 14th century. Dado was likewise used in the 18th century.