I noticed that several of the bolts on my '67 CL77 have what appears to be an "8" on the head of the bolt. Actually, it looks more like a zero with two large dimples in the middle, instead of one.
In all cases, they are 8mm bolts. At first, I thought that it was simply a size designation on the head. But later I thought it might be a grading marking as in Grade 8.
So, does the funny looking 8 on these bolts mean they are high strength, Grade 8 bolts, or just that they are 8MM threads?
While on the subject, did Honda use hardened bolts on their bikes, or were all the fasteners pretty much Grade 5?
Thanks,
Rob
Bolt strength designations
Hey Snake,
Modern designated SAE Grade-5 is the same as modern metric Grade 8.8 (see link), which is an adequate bolt strength for the CL/CB's. SAE Grade 8 (usually matte black finish) is the same as metric 10.9 and 12.9 ... super duper tensile strength hardware. Nothing we need unless we're going racing. That being said ... I haven't a clue as to the history of the designations and why a 1960's 8mm bolt has an 8 on it. Perhaps it was an 8.8 and one wore off? Modern SAE/Metric grades: http://www.boltdepot.com/fastener-infor ... chart.aspx ... and for bathroom reading: http://en.wikipedia.org/wiki/Screw Dana
1966/7 CB-77 Red of course 1976 CB-550F (project over-budget and under-funded) 1985 GS-450S (Land Speed Racer) Thanks for that link, Dana. I did not realize that there is no metric equivalent to Grade 2 hardware. I was also not aware that the metric standards used a different designation for their grades.
There is no chance the bolt is worn. This symbol is clear as new on several bolts. I have seen other metric bolts with the size indicated on the head. 6mm is the smallest I've seen. But that said, this could just be a vendor marking and have nothing to do with the thread size or strength. The reason I was asking is because I'm replating hardware and wanted to know the risk of H2 embrittlement. I'm baking all the hardware after plating to drive out any H2 just to be safe. But it is good to know that all the metric hardware on these bikes is Grade 8.8. regards, Rob Rob, starting in 68 Honda had an 8 on all of thier hex head bolts. The 68-early 69 had a really large 8 on them, sought after by restorers of those year bikes as correct for a restoration. The 8 got much smaller at some point in 69, and is still used today. Pehaps they are trying to foll us all into thinking that all of thier bolts are grade 8 ?
Davo davomoto
64 CB77 63-7 CB77 Cafe' 67 CL77 64 CL72 66 CL77 big bore flat tracker Many others! Early Harleys have similar markings on their bolts that make them highly collectible. My guess is that funky looking 8 is a vendor marking. Since my bike is a late '67, they probably started using the bolts by then which is why I find them here and there.
Guess I won't be throwing any of those away. You probably could make a good buck by buying all you find at swap meets and then replating them for resale. regards, Rob
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