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Killing the myth of the Grade 5 bolt.

There are so many old wives tales inside of the hot rod world. It particularly makes my blood pressure rise a bit to see a semi-mainstream media publication let one of their editorial writer, who happens to own one of the most recognized hot rod name brands, continue to enumerate and lend legitimacy to those myths.

 

Most of these are pretty harmless, but to state that a grade five bolt is preferred over a grade 8 bolt when mounting suspension components is really dangerous. This from the September 2011 Goodguys Gazette,. written by Brent Vandervort.

 

In actual fact, Grade 5 bolts are often preferred over Grade 8 . A Grade 8 has a very high tensile strength, but can be brittle. In applications such as suspensions, a very high number of load/unload cycles can produce work hardening, which produces an immediate, or catastrophic failure. It’s often much safer to use a Grade 5 bolt which will bend, thus providing a warning, rather than a Grade 8 bolt breaking without warning. As long as the Grade 5 bolthas been sized large enough to take the expected load, we don’t want to trade toughness (resistance to stress cycles) for the ultimate tensile strength of the Grade 8 fastener.

 

While he did leave himself a caveat with the statement of properly sized hardware for the task at hand, this subject has been debated and discussed on numerous message boards. Google for yourself and read the threads if you are interested.

I have read numerous pages of information regarding this subject because logically it never made sense that a “softer and malleable bolt” GR5 would ever be superior “than a hard and brittle bolt” GR8. What in the hell is the purpose of even making bolt with higher gradings than the 5, why would anyone make a brittle bolt?This makes no logical sense.

And furthermore, the issue of toughness. Why would a bolt of a lower grade be “tougher” and therefore more resistant to stress cycles than one of a higher grade that is stronger in tensile strength? Again, this make no logical sense.

Well, when logic fails the observations of these wives tales something is obviously wrong. Using this reasoning, an even lower grade bolt than a 5 might even be preferred because its even more malleable therefore tougher, cough. I can visit websites like SAE and BoltScience and get true and factual, means tested information without the hotrodder spin.

 

Please, if you are even remotely interested in this, open and bookmark these websites and tables.

 

The Engineers Handbook

Bolt Science

 

This thread on Pirate 4X4 is a very enlightening read, posts #9 and the response from Billavista #11 fit the discussion to a T. And here is the summary if you don’t care to click:

 

Then there’s fatigue strength. Bend a piece of metal back and forth a bunch of times; it may not break right at first, but it will break eventually. For any given metal, there is a fatigue limit, which is lower than the ultimate load. Below the fatigue limit, bend it as many times as you want and it won’t break; above that, it will eventually break. Again, in general, the higher the ultimate strength, the higher the fatigue limit.

Finally there’s impact loading. This is tested by notching a steel bar and hitting it with a hammer (very precisely, of course). This is the one case where a softer steel might do better, as harder materials tend to be more brittle. However, for most of our applications it’s not that important (unless you’re running a snowplow or trying to snatch a stuck Jeep out with a chain instead of an elastic nylon strap), as the suspension tends to damp out and spread loads below the sharp spike necessary for impact failure. Also, even grade 8 bolts aren’t all that brittle; after they’re heat treated to get the ultimate strength up they’re tempered to bring back the impact strength. Impact strength might be an issue if something’s loose, so that it shifts and bangs around before it hits whatever is stopping it (i.e. the loose bolt).

Conclusion: grade 8 bolts are stronger in virtually any application on a Jeep. Whether you need that strength, and want to pay extra for it, is another issue (though I bought some 5/16 grade 8’s yesterday for $0.60 each; grade 5’s were only ten cents cheaper). There may also be situations where you may want the bolt to fail before the expensive part it’s holding breaks, but that’s another issue. ”

 

 

As Billavista said, Grade 8 bolts are stronger. The scientific data supports it and real world testing proves it. Brent is wrong and has done damage to the hot rod community for pushing such an ignorant myth.

I have a challenge for proponents of GR5 being better suited for suspension use to find one or more makes of mass produced cars or trucks that use lower graded hardware on suspension components, take a picture and send them to me or post them here or somewhere public where we can see the evidence.

 

It is far more important to size and properly torque your hardware than any chemical or mechanical thread lockers can overcome.

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Kickbases

I built a few of these for myself, but as good news travels fast, people found out about them and wanted them. I built them with some future-proofing as best as I could see by making the foot pedal for pullrod or pushrod configuration. Also putting in ten different axle pivot positions so you can choose the leverage you want.

I had ordered an Eastwood deep throat shrinker stretcher with stand to fulfill an immediate need during the chop on Richard’s Four-door Mercury and man was I ever disappointed. It didn’t even work as shipped without modification, the pullrod was about 4 inches short of working AND it needed to be bolted to the floor. Or at least a large plate that would be a pain in the ass to move about the shop. I needed mobility and stability. So a few hours of dreaming on my Alibre’ software and I came up with a base that would meet my needs.

Alibre' design of the Kickbase

Postprocessed the files and CNC cut the plates out of 1/4″ steel plate and TIG welded my prototype machine together. This first unit had a solid body 3/8″ foot pedal on it and I used a clevis to connect the pullrod. I found out shortly some limitations to this design so I cut a pair of 3/16″ plates and was able to use a HEIM joint instead of the clevis. This freed up the feel and gave me the range of adjustability I needed. The arm pivots on bronze shoulder bushings and has a 3/4″ axle retained by a pair of snap rings. With every hole reamed to size, changing pivot positions was fairly easy to do. Once I found the arc and foot position that felt the most comfortable I threaded some heavy wall tube and welded on a six pointed thumbwheel. This also was changed out to a lighter setup and I added a pair of counter springs to the back of it to improve the pedal feel, it was just too light and was far to easy to over shrink the workpiece.

First mockup of the prototype

It didn’t take us long to put it into use…

In use on the Merc project

 

 

The most recent one out the door went to our new friend Douglas, member of the Arizona Artist Blacksmiths. He had me build an adapter to work with his Lazze branded Shrinker/Stretcher. I machined an aluminum base adapter and fabricated a new upper clevis to attach to the Lazze piece. I have these on file and can produce them for your machine also.

 

 

Other than the minor updates to the foot pedal arm and the pullrod itself, the design has worked fantastic. There are 7 of them in the world now with two available right now. Hit the E-store if your interested in one.

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1959 Chevy truck frame for Bruce

Bruce had bought a kit from Morrison A&M for his truck and had done the majority of the installation himself. He didn’t realize just how much work those universal kits take to install. So he contacted us to check his work and if it was good to TIG weld everything in place. When he dropped it off, we discussed what had been done and what needed to be done. The frame still needed boxing plates for the front and for the rear plates to be final welded. I offered to build a tubular crossmember system just like the ones we built for our frames and Bruce went for it.

Brian and I set off on a metal flinging frenzy of crossmember removal, cutting, grinding and tube bending. A bit more measuring and I placed the engine and trans then fabricated a nifty set of engine mounts that clear the steering rack and pinion. Thirty plus hours later, we had this!



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Fab-table fab

Been a busy few months here, this spring has been interesting for sure.

We had been without a large fab table since Adam pulled up stakes last year. The small setup table had been good enough for the last year but now we have new jobs coming in and the need for a new table was paramount. I prefer a larger flat sheet table with threaded holes for attaching fixtures and clamping down components, the last table had random holes that fit the individual fixtures I built, the new one has a grid for more universal measurement and hold downs.

I started off by deciding exactly how large I wanted it to be. My last table was 4X16 foot and was perfect for building narrow classic truck frames. It was a bit narrow for some of the other cars we were contracted to build. This new table is 5X12 and only 20″ off the floor. The deck is 1/2″ A36 steel and reasonably flat and the frame is made from 8″X 1/4″ channel iron.

Here is a few drawings of what I intended to build.

 

While waiting for the steel to show, I plasma cut all the legs and cut all the gusset tubing and reinforcing materials.

Just as I wrapped up the cutting and the new top and beams showed up and got to cutting the beams into the correct lengths and then cut forklift holes for moving in the future and a series of “keyholes” in the side beams to attach different fixtures or just chain binders for straightening, repair or just holding down unruly frames and assemblies.

With all the parts cut and prepped, the layout begins and the sub assemblies get welded up and test fit.

Now the real assembly begins, I started by squaring one end and inserting the end gusset tubing and welded it solid.

I then installed the first of the two center support beams, squared it, diagonally measured it and welded it in place. Then moved to the second support beam and did the same procedure.

Last was the other end beam and gusset. It went in surprisingly well, only needing a bit of tension to take the twist out of the side beams. Of course I diagonally measured each cell of the frame as I went and also checked for squareness overall. It was square to less than 1/16″.

Frame done and square I installed the center leg and support then the four perimeter legs. Rolled it over and welded everything from the top.

Quick coat of paint and install the swivel feet, level the frame and put it in it’s final resting place.

The table top was placed on the frame and as luck would have it, my plate was very flat. Only minor waves which was a bit of a surprise. Instead of welding the top to the frame I decided to bolt it down with flat head hardware tapped into the frame. Four holes on each of the end beams and the two center beams hold it in place nicely. I also scored a heavy centerline mark in the surface to aid in building and fabricating.

The last task before put into use was to drill and tap 168 1/2-13 holes in the table surface.

 

Now the fun begins! Building new fixtureing and tooling. But at least we have a solid base to work from now.

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Just gimme some traction!

Kevin brought his pro-built ’32 Roadster to us to solve a traction issue.

He had the car built a few years back by another shop here in town. When they set up the car they used common street rod parts but set them up at a ride height they were not intended to be used at. The rear was set up with a triangulated four link and Aldan coil overs. Even with sticky slicks, he couldn’t get decent 60′ times due to the tires dancing and skipping around.

We set the car up on the rack and started measuring things and found he had -65% anti-squat! It’s a wonder he could drag race this car at all. We even tried doing a smokey burn out but could barely leave black marks on the pavement. Notice the exhaust getting pinched between the lower bar and the frame.

We discussed our options and Kevin decided to ditch the under car exhaust for a cone/lakes header arrangement and that freed up the under side for our favorite, the torque arm. I crunched some numbers and determined we needed to shorten the rear links and also raise them about 2″ from their original mounts. With the 39″ long fabricated torque arm and new lower mounts (plus a new panhard) we were able to deliver a 138% positive anti-squat!

Kevin took the car out for a test drive and was very pleased at how much more controlled the car felt. The dancing deuce is no more!

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Machine tool repair and rebuilding

I was given a derelict, Italian made cold saw by a very generous customer who owns an aviation repair shop. He could no longer use the machine as the guard was broken. I sat on it for years  and finally got the thing wired up to see if it even worked, it works just fine except for the coolant pump which seized up and is very obsolete. Without coolant the very expensive blades do not last at all.

I finally had enough of a lull in customer work to put some work on this machine. The guard was held on with a plastic collar. This collar has to have a quick release to make changing the cutting blade easier and it had to be fairly compact to maximize the cutting area of the blade. I found a grinder guard with a nice over-center release mechanism I could re-purpose and put in a day of labor and head scratching to build this aluminum collar with a double jointed hinge that works very well.

With the mechanical pump being obsolete, I could have repaired it but chose to install a more modern electric coolant tank and foot pedal switch. I drilled and tapped the base for a fitting in the back of the original sump and fabricated a new tray to mount the new Little Giant sump pump. I then enclosed the front and sides of the cabinet with 0.060″ aluminum panels held on by Dzus fasteners in case I need to get access to the pump. The panels should keep the majority of the dirt and grime that makes my “dirty room” what it is.

Notice the small foot switch inside the cabinet. I sourced that from Mc Master Carr for $25.00.

The original cover for the coolant reservoir was broken and filthy. I tried to save it but gave up and sliced up a section of 1/4″ aluminum and machined the sump tray on one side and punched a few holes in it to mimic the stock cover. Also needed to make some hardware to hold it down tight.


And it’s ready for service!

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1931 Model A build up: Front Suspension

Last left off with the frame fab, we have done a ton since.

This HAMB thread covers quite a bit of the progress: http://www.jalopyjournal.com/forum/showthread.php?t=404411

This is one of those things that gets overlooked in the details. The aftermarket has come up with some stellar components and some not so stellar. But when you use high volume production parts, your car will look just like everyone elses. This car does use SoCal hair pins and a SoCal forged heavy beam axle but that’s about where it all ends.

This car runs the spring behind the axle, what is commonly known as “suicide” and requires special batwings or hair pins to mount the spring and carry the entire load of the front of the car. Not one to skimp out we cut and machined a nice pair for this car. Our initial mock up was using the supplied SoCal stainless steel pieces. Very nice with a shock mount integrated. Just not the parts we really wanted.

With a way to attach the spring to the axle, we needed to attach the hair pins to the frame. The shape of the frame plus the location gave us a few different options. Most people would weld a tube or bung into the frame to attach a HEIM or bushing to. We opted for stainless steel tie rod ends from So Cal and fabricated this nifty little plate that cancels the angle between the frame and hair pin.

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Studebaker stampeede


Howdy folks! Been busy as all get out with Studebakers last week. We had a 1955 Commander post coupe in for a suspension upgrade and rare 1962 Studebaker Gran Turismo in for an engine swap that may turn out to be a fairly serious build.

The 55 was really straightforward. We had previously build a clip for Mr. Desenberg’s 1960 Hawk and realized we had made a mistake in pushing the suspension too far up int the chassis causing problems installing the engine. A problem with the GT I will get to in a minute. I pulled up all my Alibre’ drawings and revised them to not only correct this issue but also refined the design and now we have a production capable clip. The installation took us about 14 hours in total from remove the front sheet metal, saw off the original suspension and install the new suspension. We included a set of our tubular control arms, Granada brake upgrade and power steering rack all for $4000.00.

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Studebaker clip

Mr. Metivier picked up his car just after we took in the rare Gran Turismo. Nice car on the outside. Someone had swapped the stock front sheetmetal for the older and cooler IMHO 53-54 sheetmetal. Brought in by our good customer, www.steeldreamz.com they were looking to swap out the really low mile small block Chevrolet engine and transmission for a more modern LS series and four speed automatic. As is our normal practice to do such a thing we removed the front sheet metal to get better access to the frame. This gives us more room to work and perform a more professional job. Doing this uncovered the previous owners work. They had installed a Fatman Fabrications front subframe. Due to design of this suspension clip, engine installation is nearly impossible without cutting the floor out and building a new trans tunnel and rebuilding the firewall. Sure it gets the car really low without dropped spindles but if it were designed with more forethought, similar results could have been achieved and made engine installation much easier.

This shows just how much of the inner fender needed to be cut away just to clear the upper control arms.

suspension into the right side inner fender

Rather than cut into the body further the installer decided to modify the suspension. Path of least resistance for him I am sure. However this created an entirely new problem, bumpsteer. Not only was the crossmember cut and dropped the rack and pinion was mounted lower off thick straps. Dangerous and crude, very nice combination.

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We are still waiting for input from the customer on this one. He want’s to replace his Mercedes Benz daily driver with this car. This is something we can do for him, just not with this mess of a front end.

What is desired is a car that will drive very well, handle and brake and last as a new car would. What we would very much like to do is replace the Fatman clip with our kit. Our tubular control arms which are not only stronger but upgrade the ball joints and use OEM rubber control arm bushings for a much better ride without the polyurethane squeak and harshness. A set of Bilstein shocks and matched springs. A Flaming River variable assist rack and pinion would definitely set off the steering feel. And if there is any budget left, we would really like to rebuild the rear suspension with a torque arm system and Bilstein coil overs in the rear.

Here’s the links to the pictures:

http://s206.photobucket.com/albums/bb93/ELpolacko/1953-1962%20Studebaker%20Hawk/1955%20Commander%20Metivier/

http://s206.photobucket.com/albums/bb93/ELpolacko/1953-1962%20Studebaker%20Hawk/1962%20Studebaker%20GT%20Fatman%20Fab%20repair/

I am going to try and make this blog a weekly thing, so, until then. Adios!

Steve