# Honey, my dog ate the hammer



## precisionworks (Jun 27, 2012)

Not only ate it but really did a job on it. The hammer is a Garland 2" rawhide faced model & one of my favorite non marking hammers. Left it on the base of the overhead crane recently & came back the next morning to this:












My first thought was to turn a solid brass insert instead of replacing the rawhide. My friend up the road brought by a piece of brass round stock 2.25" diameter (57mm) weighing 5# (2.25kg). It was too nice to chop up & make a face with so instead a new hammer would be made.

Started with the handle, a 12" long piece of 1" diameter Ti-6-4. Turned down the upper part of the handle where it will go into the brass head & knurled the grip.






Not bad looking from a distance but not enough clamping force was used to fully form the diamonds:






Good enough for a hammer handle but far short of DarkZero's perfect knurling  Used new convex knurls & new solid carbide pins. The knurls were too hot to touch after pressing this pattern.

More to follow.


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## fyrstormer (Jun 27, 2012)

That's gonna be a hell of a hammer when it's done.


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## easilyled (Jun 28, 2012)

If you're not satisfied with that knurling, then please turn it into a flashlight and send it to me.


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## precisionworks (Jun 28, 2012)

easilyled said:


> If you're not satisfied with that knurling, then please turn it into a flashlight and send it to me.



LOL 

The tool (Eagle Rock K1-201) was set up for very heavy knurl pressure & it still was not enough for a full depth pattern. My other tool (Eagle Rock K1-44) is much more heavily constructed, uses counter bored knurls & should be able to handle the increased clamping pressure.


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## wquiles (Jun 28, 2012)

precisionworks said:


> The tool (Eagle Rock K1-201) was set up for very heavy knurl pressure & it still was not enough for a full depth pattern.



I know that many times we strive to achieve perfection, but there is a point in which we got "enough" and we start a slippery slope of diminishing returns. In my humble opinion, that knurling is "way past" good enough :bow:

Will


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## 127.0.0.1 (Jun 28, 2012)

hammers made from steaks...learn something new every day


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## precisionworks (Jun 28, 2012)

127.0.0.1 said:


> hammers made from steaks...learn something new every day


LOL ... our Siberian Husky starts wagging her tail whenever that hammer is taken off the pegboard  



> there is a point in which we got "enough" and we start a slippery slope of diminishing returns.


Already slipping down that slope. Called Eagle Rock & ordered a pair of the counter bored knurls in 32 pitch powdered metal. Finer knurls displace less metal and the K1-44 is much more rigid so this should do the trick. None of this would be happening had DarkZero not posted images of his perfect diamonds. Blame Will 

Tech support mentioned that the speed of the knurl wheel should not exceed 400 rpm. I was running faster than that but will slow down when the 32 pitch knurls are mounted. 

The diametral pitch of the new knurls is 96 so the 1.000" stock will need turning down to 0.9920" for correct tracking.


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## fyrstormer (Jun 28, 2012)

precisionworks said:


> LOL ... our Siberian Husky starts wagging her tail whenever that hammer is taken off the pegboard


Whack her with it until she learns to fear it properly. :devil:


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## bshanahan14rulz (Jun 28, 2012)

What is it that makes it more perfect? Is it the symmetry of the diamond shape, or were the diamonds supposed to end up pointed or something?

I've always liked the pointed knurling like on my solarforce L2, but my 6P's knurling is somehow more grippy feeling. Metalworking seems so simple, until you actually look into it. I guess I just don't understand what qualities are thought of as good or bad in the knurling world.


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## ^^Nova^^ (Jun 28, 2012)

Have to start calling you Thor with a hammer like that, lol.

Got me thinking about a knurled V10r Ti as well now...

Cheers,
Nova


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## darkzero (Jun 28, 2012)

precisionworks said:


> Not only ate it but really did a job on it. The hammer is a Garland 2" rawhide faced model & one of my favorite non marking hammers.



Ooh, that's a nice hammer (or should I say was )! I've always wanted a rawhide hammer but the nice ones are expensive! Maybe you can "save" it by rounding it off some?

But at least I bet your dog had a real good treat & enjoyed it! 



precisionworks said:


> None of this would be happening had DarkZero not posted images of his perfect diamonds. Blame Will



Finally I get payback :nana:.....for all the times you guys made me buy stuff or inspired me to try something! Nothing like friends to keep each others motivated!




precisionworks said:


> Good enough for a hammer handle





wquiles said:


> I know that many times we strive to achieve perfection, but there is a point in which we got "enough" and we start a slippery slope of diminishing returns. In my humble opinion, that knurling is "way past" good enough :bow:
> 
> Will



I agree with Will, functionality is all that matters sometimes. The tracking looks spot on, IMO, double tracking looks far worse & a partially formed knurl is not bad at all. Sounds like it will be a good sized hammer which would benefit from a full knurl. But then again an aggressive knurl may not be easy on bare hands. You could always do a skim pass over it to make it look "nicer". But you are the master, I'm sure your end result will be outstanding as always.



Here are our hammers that my lil brother & I made. They feel nice & grippy in the hand but the almost full knurl is harsh on the hands. But I don't "use" this one & neither does my brother use his. I'd like to make me one in Ti too someday.


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## precisionworks (Jun 28, 2012)

bshanahan14rulz said:


> What is it that makes it more perfect? Is it the symmetry of the diamond shape, or were the diamonds supposed to end up pointed or something?



Since a picture speaks volumes ...






No way to improve upon that. Perfectly formed full diamonds without the broken off tips that result from knurling too deep. 

Made a partially threaded cross pin to retain the head to the handle & will try to get the handle hole bored in the head.


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## fyrstormer (Jun 28, 2012)

That knurling looks almost painful to hold. Not sure what you'd ever need THAT much grip for, unless the hammer were covered with grease.

Is that cut knurling? I've never seen pressed knurling (as far as I know) that came close to being that pointy.


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## darkzero (Jun 28, 2012)

fyrstormer said:


> That knurling looks almost painful to hold. Not sure what you'd ever need THAT much grip for, unless the hammer were covered with grease.
> 
> Is that cut knurling? I've never seen pressed knurling (as far as I know) that came close to being that pointy.



Sure you have.  Form knurling is the "conventional" method of knurling. Cut knurling did not exist way back when. A true knurl is a fully formed knurl where the diamonds are pointed & do not have flats or broken off points. 

Softer metals are much easier to fully form knurl. The issue talked about here is achieving a fully formed knurl in high tensile alloys such as Ti. Not only that, it's not very hard to work harden these "harder alloys". Work harden the piece then throw it in the scrap bin. That's one of the reasons why cut knurling excels in super steels, SS, Ti, etc alloys.

The photo above looks very aggressive but doesn't really give you an idea of how aggressive it might be without having an idea of what the diameter of it is. Although that particular piece is what I consider a coarse, maybe borderline medium knurl (I know because it's mine), you can have a very fine fully formed knurl which would not be harsh on the bare hands at all. The partial/flat knurling commonly seen on flashlights is more for asthetics rather than function. Although they do provide some added grip it's more form over function. The knurling found on many SureFire lights is function over form IMO. They provide excellent grip without being too aggressive to hurt the hands. But that is also not form knurling.


From the other thread, this is example of a fine fully form knurl that isn't harsh on the hands. But I'd prefer a more coarser pitched knurl like Barry's for a hammer handle for that size of a hammer.


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## precisionworks (Jun 28, 2012)

The fine pitch knurling is stunning. I can only hope that mine look like that.


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## darkzero (Jun 28, 2012)

Thank you Barry! But I'm pretty sure I will be saying the same about your hammer.


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## fyrstormer (Jun 28, 2012)

I definitely like the way the fine-pitch knurling looks vs. the coarse-pitch knurling. I don't need noticeable pressure-points digging into my skin. 3.6 billion years of evolution has resulted in my hands being covered with thin, shallow grooves, and that was apparently enough grip-enhancement to ensure the survival of countless generations of ancestors, so I doubt a hammer would need anything more aggressive.

IMO, of course.


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## precisionworks (Jul 5, 2012)

Here's a comparison of the heavy duty scissor tool (left) versus the standard scissor tool:





You'll notice the much thicker arms at the scissor joint as well as the heavier support at the knurl wheels. A really nice feature of the HD tool is the quick change feature - loosen the socket head set screw (red arrow) and it takes only seconds to change out a knurl wheel. On the standard tool with pressed in pins it's a 15 minute job.






The HD tool has 32 pitch powdered metal knurls while the standard tool has 21 pitch convex cobalt knurls.


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## fyrstormer (Jul 5, 2012)

So that's what a knurling tool looks like. Do you have to adjust it sideways after each stripe of knurling is complete, or is there a mechanism that moves the tool sideways automatically?


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## easilyled (Jul 5, 2012)

darkzero said:


>



Simply stunning knurling Will.
Is the knurling at the bottom of the picture above "cut knurling" as opposed to "form knurling" ?
I ask because to my eyes the diamonds seem flat rather than pointed (unlike the first two examples)


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## gadget_lover (Jul 5, 2012)

fyrstormer said:


> So that's what a knurling tool looks like. Do you have to adjust it sideways after each stripe of knurling is complete, or is there a mechanism that moves the tool sideways automatically?



The way to use a knurling tool is with a lathe. The tool takes the place of the cutting bit, and will move right and left when you move the saddle. 

You usually don't knurl a stripe, you move the tool to the left while it's engaged and the lathe is spinning the whole time, so it makes an overlapping spiral. It's important that the knurls "track" ( fall in the same grooves each revolution) to make this work.

Daniel


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## fyrstormer (Jul 5, 2012)

gadget_lover said:


> The way to use a knurling tool is with a lathe. The tool takes the place of the cutting bit, and will move right and left when you move the saddle.
> 
> You usually don't knurl a stripe, you move the tool to the left while it's engaged and the lathe is spinning the whole time, so it makes an overlapping spiral. It's important that the knurls "track" ( fall in the same grooves each revolution) to make this work.
> 
> Daniel


The cutting tool can be moved while the lathe is turning and significant pressure is being applied to the cutting tool? I wasn't aware. I can see how that would make it easier to ensure proper alignment of the knurling grooves.


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## precisionworks (Jul 5, 2012)

fyrstormer said:


> The cutting tool can be moved while the lathe is turning and significant pressure is being applied to the cutting tool?



When knurling a long part the tool is traversed so that the knurl pattern covers the desired area. For narrow bands of knurling the tool is not traversed but rather fed straight into the part - the pattern is the width of the knurl wheel.



> I can see how that would make it easier to ensure proper alignment of the knurling grooves.


Alignment of the grooves (aka tracking) is a function of matching the number of teeth in the knurled circumference with the knurled diameter of the part. There are formulas & Excel spreadsheets that will calculate this but it's easier for me to use a table like this one: http://www.engineersedge.com/manufacturing_spec/knurl_chart.htm


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## darkzero (Jul 5, 2012)

easilyled said:


> Simply stunning knurling Will.
> Is the knurling at the bottom of the picture above "cut knurling" as opposed to "form knurling" ?
> I ask because to my eyes the diamonds seem flat rather than pointed (unlike the first two examples)



Thanks Daniel. I don't have a cut knurler, those things are expensive! Maybe I might get lucky one day like WillQ.  

I used the same scissor form type knurler for all three of those pieces pictured. The bottom one was just a piece I was practicing a partial (not fully formed) knurl. Close up you can see the finish was not great to start out with. I was bored one day & turned it into a 2x123 e-series body. Another method is to partial knurl, then do a skim finish pass to make the knurls flat.
















precisionworks said:


> There are formulas & Excel spreadsheets that will calculate this but it's easier for me to use a table like this one: http://www.engineersedge.com/manufacturing_spec/knurl_chart.htm



Great site, very informative. Thanks for the link Barry!


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## easilyled (Jul 6, 2012)

darkzero said:


> Thanks Daniel. I don't have a cut knurler, those things are expensive! Maybe I might get lucky one day like WillQ.
> 
> I used the same scissor form type knurler for all three of those pieces pictured. The bottom one was just a piece I was practicing a partial (not fully formed) knurl. Close up you can see the finish was not great to start out with. I was bored one day & turned it into a 2x123 e-series body. Another method is to partial knurl, then do a skim finish pass to make the knurls flat.



Thanks for the explanation Will. Bottom line is whatever you do always turns out great since you are a perfectionist.
I'd love to have a Ti light with that beautiful full-form diamond knurling of yours one day.


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## precisionworks (Jul 6, 2012)

This is a learning process ...

There is one obvious difference between the standard tool & the HD tool - it has almost no spring in the arms. That means it has to be set slightly less tight than the standard tool. On top of that the 32 pitch knurls require less pressure than the 21 pitch knurls. Bottom line is that it is really easy to over knurl & break the tips off the diamonds. 

Looks OK until viewed under magnification 

21 pitch on top & 32 on bottom:


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## darkzero (Jul 6, 2012)

precisionworks said:


> Here's a comparison of the heavy duty scissor tool (left) versus the standard scissor tool:



Barry, got me curious.....

I have the HD K1-44 but not the shoulder type like your K1-201. Would those be the counterbored wheels & do they require different types of pins? Just curious what the wheels & pins look like when removed from the tool.




easilyled said:


> Thanks for the explanation Will. Bottom line is whatever you do always turns out great since you are a perfectionist.
> I'd love to have a Ti light with that beautiful full-form diamond knurling of yours one day.



Thanks for the kind words Daniel. I'll think about it, maybe one day.


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## precisionworks (Jul 7, 2012)

> Just curious what the wheels & pins look like when removed from the tool.


You cannot imagine how long it takes to remove the wheel & pin ... 14.3 seconds according to my timer app  If you plan to run different pitch knurls this is the tool to have.






Used this tool to apply bands of knurling to my V10R:






The very fine pattern is the result of intentional double tracking. The goal was to have all the bands look like the two at far left. Instead they came out the way they wanted to


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## chesterqw (Jul 8, 2012)

this is bad, i don't need a hammer and want one.


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## precisionworks (Jul 8, 2012)

chesterqw said:


> this is bad, i don't need a hammer and want one.


LOL 

Working on V10R's today so the collet chuck is mounted on the lathe. When those are done the jawed chuck goes on & the head can be turned smooth & grooved. Then it gets a handle hole bored & a cross pin hole drilled ...


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## jacksmith (Jul 9, 2012)

hammers made from steaks...learn something new every day !! :twothumbs


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## darkzero (Jul 14, 2012)

precisionworks said:


> You cannot imagine how long it takes to remove the wheel & pin ... 14.3 seconds according to my timer app  If you plan to run different pitch knurls this is the tool to have.



Yes, I also have the K1-44 so it has the same method of changing the wheels, except mine is not the shoulder type. 

Do you have to be extra careful when pressing in carbide pins in the standard tool? Didn't know that was possible, figured the carbide pins would chip very easily.


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## precisionworks (Jul 14, 2012)

darkzero said:


> Do you have to be extra careful when pressing in carbide pins in the standard tool? Didn't know that was possible, figured the carbide pins would chip very easily.



Will,

I had exactly the same concern. The ends of the pins are straight cut as they arrive from Eagle Rock. A 45° chamfer was ground on one end of each pin using the diamond coated wheel grinder (same one is used to sharpen TIG tungsten's). The tool & tool block were placed on the arbor press platen & shims were used to level the tool so it was exactly 90° to the platen. A guide bushing was machined so that 2/3 of the pin was supported at the start of the pressing. Once the pin was flush with the top of the guide bushing it was removed & the pin was pressed fully through the outside arm & just slightly beyond. That allowed lifting the knurl upward to engage the pin - missing the center of the knurl would have destroyed the pin & the pin to knurl fit is quite close. Once the pin was centered in the knurl it was pressed through the knurl & through the bottom arm.

All the above took some time, probably 30 minutes to press in both carbide pins. I'd already spent at least 15 minutes removing the steel pins & straight knurls so this is not a quick process.


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## precisionworks (Oct 9, 2012)

Bored the head for the handle which had been turned to just over 3/4" ... 0.756" to be exact. Wanted a nice press fit & bored to a diameter of 0.752" with the hole extending 87% of the way through the brass. Cleaned & prepped the Ti & the brass with acetone, smeared a little Loctite 680 retaining compound on the handle & gave it a shove with my 3 ton arbor press. Went about 1/4". Hmmm.

Called my friend at the big shop down the street & asked if I might use his 50 ton press for a minute or two. Went right over, set the brass end on the table & pushed on the handle. Pressure gage read 15 tons when the handle started to slowly go home. Stayed on the pressure until the gage spiked & that indicated the handle was as far in as it could go. 

Had planned to cross drill for a steel dowel pin but with a 15T press fit it isn't coming apart. Hand finished the head with an antique brass patina. I'll probably show this for sale on my website & hope that nobody will pay the asking price of $995.00 :nana:


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## easilyled (Oct 9, 2012)

Looks like you've nailed it! 

Excellent work. :thumbsup:


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## Kestrel (Oct 9, 2012)

precisionworks said:


> Not only ate it but really did a job on it. The hammer is a Garland 2" rawhide faced model & one of my favorite non marking hammers. Left it on the base of the overhead crane recently & came back the next morning to this: [...]


Did you bother to do a search before creating a new thread on such a common topic?  You're all banned, lol.
Love all the knurling work BTW, you folks are true artists.


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## StrikerDown (Oct 9, 2012)

Now if your dog can chew this one up he's got some brass ones of his own!

Awesome piece of hardware Barry!


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## precisionworks (Oct 9, 2012)

Thanks to all of you for your kind words 

Nearly killed myself trying to press the handle with my little arbor press ... had a piece of 4" square tube at the base, a 48" solid rod on top of that, the head & handle & then the ram. Popped out twice, got a bruise or two on my ankles but not much blood That's when the hydraulic press came into play.

Forgot to show earlier how the head was supported in the chuck but cannot seem to add images at this time ... anyone else having a problem?


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## guardpost3 (Oct 9, 2012)

Thats really impressive. I am no machinist (far, far from it actually) but I enjoyed reading this thread. The pictures of the knurling and their related processes were great. I had no idea how that was actually done.

So, I guess after 15 tons of pressure, maybe the locktite was a bit overkill...


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## StrikerDown (Oct 9, 2012)

Barry, what is the advantage to pressing the head on the handle as opposed to threading/tapping and screwing together with a little loctite?

Other than bruises and bloody excitement that is :devil:


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## precisionworks (Oct 10, 2012)

guardpost3 said:


> So, I guess after 15 tons of pressure, maybe the locktite was a bit overkill...


LOL  Belt & suspenders approach.



> ... what is the advantage to pressing the head on the handle as opposed to threading/tapping and screwing together ...



Ray,

A press fit is faster (if you figure out the correct dimensioning). Threading the Ti handle would have been easy but threading the head - no. The specific ANSI alloy designation is MM (mystery metal) & I go out of my way to avoid working anything that has no material cert. But being cheap & having a friend with the correct size of MM led me down this bumpy road. Wild guess on the alloy is C22000 Commercial Bronze, machinability rating 20 (reference material is C36000 free cutting brass @ 100). 

Never did find the sweet spot for drilling but had to use a very high relief angle & that makes the lips fragile - chipped three twist drills during the process. Final drill size was 11/16" and it stalled the 2hp spindle quite a few times before reaching the bottom of the hole. Just like Ti-6-4 this material closed in around the drill bit & made it miserable to drill. Hard enough that it shouldn't deform nearly as much as the solid copper hammer I have.

Total weight is 5# 10 ounces (2.55 kg) versus 4# 1 ounce for my copper hammer. Since the copper hammer has a lighter head & a handle that's 50% longer it's easy to swing with great force. But it's a pain to use when tapping a chuck taper into the tailstock because the handle is too long for close work. The shorter & heavier Ti hammer should be just the ticket.

It looks good on the tool board behind the lathe & the antique finish takes away the "new tool look". The swelling on my left ankle should go down in a day or two so my boots can again be laced up :devil:


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## precisionworks (Oct 11, 2012)

Update: Used the hammer yesterday to seat the big Jacobs 20N in the tailstock taper. Nice is an understatement. Awesome is still a bit short. %@*&#(!) phenomenal is about right 

Much easier to use than the longer handled 4# hammer. Heavy hits on the chuck left almost no marks on the hammer face & still did not mark or deform the chuck nose. This one's a keeper.


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## darkzero (Oct 12, 2012)

That hammer turned out nice! :twothumbs


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## precisionworks (Oct 13, 2012)

darkzero said:


> That hammer turned out nice! :twothumbs



Thanks Will 

Started it two or three months ago & tripped over the parts this week while machining lights for members. Decided it was time to either finish the project or toss the parts in the junk pile ... hard to scrap out $100 in titanium & a big chunk of brass/bronze :devil:

It's a good exercise for anyone who needs a short sledge hammer (& we all NEED that, don't we). Milling, turning, knurling, facing, boring, press fits, this one has it all.


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## Chicago X (Oct 13, 2012)

What a beauty.

Is HammerEnvy a word ?


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