Paring chisel, beta test.

[Imakethings]

A carpenter I met gave me a bit of a challenge, he does a lot of very fine joinery and woodwork. So we discussed what would work best for him and what he wanted, so after some sketches and discussion this is essentially what we came up with.



The notch in the side was unavoidable, it was a chunk of scrap leaf spring and this is a beta test to see if it generally fits with what he wants. The next one will be about 2.5" wide, this one is only about 1".

Thoughts? Feedback? Etc?

[Crex]

Looks pretty good so far. Proof will be in the use.
I did a set of 6 for a fella a few years back out of three layer damascus that turned out very nice......he used them once then had them mounted in a display box. Said they were just to nice to use.

I might would pick a different steel, such as O1 or 1095 for a little better edge retention.
Just remember, the biggest key to good chisels (and knives in general) is heat-treatment and edge geometry.

[Ray Rogers]

Excellent grind lines, Marc! But 2.5" ..... is that really practical? I suppose he must know what works but it seems like it would be pretty difficult to push something that wide through a piece of wood even using a hammer ...

[Imakethings]

Ray, I'm with you on the size being excessive, but it's what he asked for. He wants it and I've never had reason to make a chisel that size before. I didn't grind this one either, about 75% of it was forged into shape rather than doing stock removal.

Crex, considering that it's 5160 it should hold it's edge fairly well. I tried it out a few times to see how it cut end grain in wood and was pleased with the results, I tempered it fairly hard so I expect it should do fairly well for wear characteristics.

[Doug Lester]

Not to beat a dead horse, but what makes you say that you are working with 5160? Did you have it analysed? That is just one possibility of what alloy that could have been used for that spring.

Doug

[Imakethings]

Doug, I pull the manufacturer specs from the vehicles I get my springs from, while it does vary to some extent between manufacturers there have been international standards in place that have designated 5160 as what HAS to be used in leaf springs in every vehicle imported or produced in the USA since 1985.

Ref:
http://standards.sae.org/j510_198505/

[Ray Rogers]

Wouldn't be the first time I was wrong but that doesn't sound right to me at all. I'm almost certain other metals are used on both domestic and imported leaf springs - but not 100% so I'd like to see that spec. The link in your post doesn't provide any useful info and it appears that might be due to me not having some membership or not paying for something, I'm not sure. Anyway, if you have access to the info a cut and paste of the relevant paragraphs in context would be most educational ...

[Imakethings]

I have a hard copy of the standards somewhere, but there are several references in different engineering journals and papers.

Take a look at the materials section of http://www.vsrdjournals.com/ME/Issue...e_Mar_2012.pdf

This one also outlines the current standards of spring materials.
http://www.ijirset.com/upload/may/12_DESIGN.pdf

The international standard for Hot Rolled Sping Steel.
http://mechanicalebook.com/charts/mshotsp.htm

I'll swing over to the college library and see if I can dig up a copy of the current standards for you.

[Doug Lester]

I would be interested if that is true. Of the links that you have provided it looks like the first is a comparison of 5160 with 9260 and their equivalents. The second is about compound springs and the steel that they mention is more like 1095. The third is just a stat sheet comparing something on the order of 5160 with a 9260 equivalent.

Doug

[Imakethings]

Hope I've not been misunderstanding what I've been reading then. I'm not an engineer, I'm a biologist.
The IJIRS article was not the one I ment to link (I think) and at this hour I'm too lazy to go digging through my browser history to find the right one.

The VSRD journal article points out, to my knowledge, the most common variants of steel used in automotive springs,
SUP 9 standards can be found here:
http://www.tenhiko.com/search/zairyo...ukou/bane.html
And a rather interesting read on some testing on the tempering/hardening of SUP 9 steel can be read here:
http://publications.muet.edu.pk/rese...pdf/pdf171.pdf


EN45 is here:
http://www.steelexpress.co.uk/springsteel/EN45.html
and the pdf here has a quick rundown on basic HT process and some interesting stuff on cryo treatment of EN45:
http://www.seipub.org/fwr/paperInfo.aspx?ID=2989

Both Oil quench steels with with good wear characteristics, granted SUP 9 is not ideal for my purposes. Rough HT for both (unless I've been doing something wrong) is pretty much the same.

Doug, I'm getting a bit argumentative about something I read years ago. I'll freely admit that I can be wrong, but I'm reasonably certain that the standard is some flavor of 5160. If I'm wrong I'll happily eat my words.
Since I looked through my bookshelf I can't find my copy of the SAE standards (grandad was a mechanical engineer), I've ordered a copy on loan through the local college library and will update once I get my paws on it, regardless of whether it contradicts me or not.
Well done, now I'm full of doubt on being right or not.....

[Crex]

Marc and Doug, I really see this as great opportunity for knowledge share with documentation. This is what these forums on KNF have always been about. All will benefit, good stuff here.

On the edge retention, Marc, may just be the methodology I use for HT, but I have observed that I get more carving miles out of my O1 and 1095 blades on planes, chisels and carving knives. I like using the old hand tools a lot so it's not just a "passing" observation. I've always considered 5160 more of an impact oriented steel for big choppers, bowies, axes, etc. and not small blades, but again that might be mostly due to HTng methods.

Ray, by nature the paring chisel is used to skin/shave that last little bit of wood for a tight fit and it's bevel angle is not really conducive to hogging out chunks under impact. More of a hand push - light tap operation. Lot of the old world carvers would have several different bevel grinds and widths just in their "paring" set. My Granddaddy was a master cabinet maker and ardent proponent of capital punishment.....he was quick to justice if he caught you abusing his prized Swiss set of chisels. My skullcap would drive a phrenologist nuts.

[Ray Rogers]

Thanks Carl, I'm no wood wood worker at all but that makes sense out of that wide chisel.

Marc,

I've had to really learn to restrain myself from making blanket statements - which I am very prone to do - as they generally come back and bite my behind. I think the 5160 statement will probably turn out to be one of those for you but don't let it bother you, just learn to be more cautious as I have had to do. The more I think about it, the more certain I am that no such guideline exists. I now recall reading that once upon a time most automotive leaf springs were made from 5160 but in the last few decades 4140 and 9260 (and doubtless others) have taken the place of 5160. The article further said that heavy truck leaf springs could still be 5160 but not all were. When the early Honda cars first arrived on our shores the coil springs in their front ends were said to be 1095 but that is no longer true (if it ever was).

It is widely understood now in industry that manufacturers will use any steel that is available at the time they need to purchase steel as long as the material meets the specs for the part they need to make. That's why even the manufacturer of a part might not be able to tell you with certainty what steel was used to make some 10 year old part. As for foreign cars, much of their steel is our steel recycled which leads to many new alloys that are more or less the same as X and , hopefully, functionally the same but not identical in composition (and therefore HT). We'd have no way to demand that 5160 was used for springs because they couldn't guarantee an accurate composition without making fresh steel. This is why we see a difference even in the simple 1084 that we get from Aldo when compared to 1084 from other sources - the mix is close enough to meet the spec for being called 1084 but it has elements in it from being recycled that aren't desirable from a knife making point of view, or the proper elements are there but at the low end of the specification.

Anyway, the bottom line is" if you don't buy it from a reputable dealer then it's mystery steel. Mystery steel should be avoided by inexperienced makers but can be used to good effect if you go to the trouble of carefully working out what HT gives good results with it. Even after that though, I would hesitate to put a name on the steel......

[Doug Lester]

Marc, nothing personal, I was just trying to understand why you were certain that the steel was 5160. There are ways of finding out. BTW, you're not the only person who has read something that said something like all auto leaf springs are 5160 and all auto coil springs are 9260. At one time these lists were probably more accurate than they are today. Once I even read a nice little on-line article that said that it was impossible to forge weld in a gas forge. There's a lot of misinformation out there. I think what we might have here is a case where you think that you might be working with 5160, and you may very well be right, but there are other possibilities.

Doug

[Imakethings]

Yeah, I was starting to take it personal and I know it wasn't meant as such. I know better, but it still started to creep in. Sorry about that and thanks for understanding and giving me a minute to quit over-reacting.
The more I've dug back into this the more it appears that I'm close to right, but not entirely right. It appears that leaf springs are usually something comparable to 5160 or it's an exotic and confusing mix that has the right characteristics to be used in that application.

[ericbrinkerhoff]

Enough about the steel.I dont care If its made out of pig manure and elmers glue ,thats a cool chisel.
Seriously ,though, Ive done a lot of timberframing construction and 2.5" is not too big for that..Those bevels on the back make it look like it would slide right into a corner in a mortise.
I know a lot of timberframers who would like a chisel like that.