Wilsons Sandbox

--- In DSN_KLR650@yahoogroups.com, "wannabsmooth1" wrote: > I've hardness tested several of the fasteners, from different bikes. > Many of the fasteners do qualify for the "compressed oatmeal" > category. Ex: a local guy called me to see if I had some spare triple > clamp bolts, as his had twisted off. Just for grins, I hardness tested > them. They were some of the softest bolts I had ever tested, that were > made of steel. This was even after they had work hardened a little, > due to the stretch. I'm pretty sure these were "torqued" by hand at > some point, leading to the above result. > > The rotor bolt is a good quality, bolt. The early subframe bolts > were/are soft. Later subframe bolts are better, but still easy to upgrade. > > A torque wrench is fairly important for working on some of this stuff. > Some people think their particular feel is better than a torque > wrench. Several years ago when I was a quality control manager in an > aerospace manufacturing facility, I read a report of a test of > mechanic's feel vs actual torque readings. Experienced wrenches....... > Results were quite varied. Large fasteners were usually under-torqued, > small ones over-torqued. > > Many of the fasteners on the KLR fall into the "smaller" classification. > > All the best, > > Mike > Eagle Mfg & Eng since 1990 > San Diego, Ca

--- In DSN_KLR650@yahoogroups.com, "Jim" wrote: Jim, here's a little info. It would take a long time to give you all the info available. You might want to go to your local industrial fastenenr supply place and talk to their tech guy, if you have time. > What does hardness have to do with a broken bolt? How can a bolt be > soft? What is work hardened? What makes a good quality bolt? > > Thanks, > > Jim A17 > Jim, Bolts are available in different hardnesses (grades), which comes from the steel alloy they are made of, and the heat treat condition, or temper, of the material. There is a relationship of hardness, to ultimate tensile strength - tensile meaning the amount of weight the material can hold in an attitude of tension - the most common use of a bolt. Other mechanical qualities are compression, and shear, for instance. If a material has a hardness of 40 on the Rockwell c scale, the ultimate tensile strength is approximately 182,000 pounds per square inch. i.e.; a piece of stock 1 inch square would strech, and then fail at 182,000 pounds of load. It would hold 90,000 lb, with safety factor. The material stretches some before it fails, during this stretch it work hardens, becomes slightly stronger, just before it fails. I don't have a material handbook in front of me - I'm at home right now. As an example: a material has an ultimate tensile of 135,000 psi, it may start to permanently deform at 110,000 psi of load, between 110,000 and 135, 000 it will work harden, until failure. (this is just for example, and the numbers are probably off some)Bolts commonly stretch slightly when torqued. A good bolt is one that will do the job, with safety factor. When one is buying tons of fasteners, $$$ always come into play. Free machining alloys are lower cost to fabricate, and cost a little more for material than the really cheap alloys. Metric bolts (ISO rating system) use a different rating scale than SAE, or ASTM (US) system, but you could google, and find the relationship. A case bolt could be ISO grade 5.8 for the KLR650 (probably is), and be perfectly adequate. The subframe bolts should be at least 10.9, and I like to go all the way to the 12.9, stronger yet. Hope this answers, and/or helps a little. All the best, Mike Eagle Mfg & Eng since 1990 San Diego, Ca

> What does hardness have to do with a broken bolt?

>How can a bolt be soft?

>What is work hardened?

>What makes a good quality bolt?

> Thanks, > > Jim A17

>The subframe bolts should be at least 10.9, and I like to go all the >way to the 12.9, stronger yet. > >

> wannabsmooth1 wrote: > > >The subframe bolts should be at least 10.9, and I like to go all the > >way to the 12.9, stronger yet. > > > > > Just as a point of information, the subframe bolts I took out of my

> KLR were stamped as 10.9 grade, and the ones I bought from Eagle Mike > and put in were a 12.9 grade. So it appears that Kawasaki at least on > paper is no longer using compressed oatmeal for the subframe bolts, > though with the Chinese bolts you can never tell whether the actual > steel reflects the grade stamp. > > -E

>On 8/21/05, Jim wrote: > > >>What does hardness have to do with a broken bolt? >> >> > >?? Are you serious? More hardness will sustain more load and stress >before breaking. Well, in most contexts, it does depend on the >load/use. > > > >>How can a bolt be soft? >> >> > >Depending on the alloy of the metal and the treatment it is given or >how it is made, the hardness will vary. > >If you want to see soft, wait until a few of your side panel screws >get some rust on them. A screwdriver is probably five times harder >than the head of these screws. They are an ad for screw extractors. > > > >>What is work hardened? >> >> > >Not a machinist so I will leave that one. > > > >>What makes a good quality bolt? >> >> > >The quality of materials and quality of the production. > >I used to sell fasteners years ago and all you need to do is pick a >few up and you can instantly see the difference in production quality. > The Chinese fasteners had just begun hitting the market and there was >no comparison when you picked up one of their grade 2 generic bolts >and compared it with a US made equivalent. The price >however....shocking difference. > >There was a company that made high-end fasteners, principally >allen-head screws, their name escapes me now, probably in the McMaster >Carr catalog. If you took a look at one of their machine screws and >compared it to a generic import, they looked like they were hand >turned on a lathe. The finish quality was a world apart. I replaced >most of the bolts on my Beetles with them as I worked on it. The >higher end screws would take and hold torque much better than generics >did. Again, I'm no machinist but it would have to do with the way the >threads were cut and the materials. > >For my industrial customers, using these fasteners to secure high >pressure fittings or using them in chemical environments, there wasn't >even a cost consideration. There was no substitution as an option. > >If you want a quick way to see what I'm talking about, grab one of the >footpeg or subframe upgrade kits with the 'metric blue' bolts. These >are the quality I'm talking about. Hold one of them next to the stock >bolts. You can feel the weight difference and see the difference in >how clean the threads and other details were cut. > > >>Thanks, >> >>Jim A17 >> >> > > >Archive Quicksearch at: http://www.angelfire.com/ut/moab/klr650_data_search.html >List sponsored by Dual Sport News at: www.dualsportnews.com >List FAQ courtesy of Chris Krok at: www.bigcee.com/klr650faq.html > > >Yahoo! Groups Links > > > > > > > > > >

> > The subframe bolts should be at least 10.9, and I like to go all the > way to the 12.9, stronger yet.

> On Sun, Aug 21, 2005 at 03:54:01PM -0000, wannabsmooth1 wrote: > > > > The subframe bolts should be at least 10.9, and I like to go all the > > way to the 12.9, stronger yet. > > I spent some time talking to my friend Ross (an aerospace engineer) > about this a few weeks ago. He said that studies in aircraft had > shown that in many applications harder bolts were more likely to fail > than softer bolts: the higher-grade (harder) bolts are more brittle, > and most bolts fail because they're loose -- a stronger (harder) bolt > made from the same alloy is _more_ likely to fail this way. He > advocated using bolts no harder than 10.9 for most applications and > adhering to a regular schedule of retorquing all critical fasteners. > > It made a lot of sense to me! It also makes the heavy-duty subframe > upgrade look a lot more appealing than the "lite blue" version I > went for.