Honda Metric Hardware Pitches

Dezdan

Well-Known Member
Does anyone know is the same metric sized hardware on a CT70 will have the same pitch throughout the bike? I'm assuming any M4 has a 0.7 pitch, but....

M5 Bolts/Nuts, are they a 0.8 or a 1 pitch?
M6 Bolts/Nuts, are they a 0.75 or a 1 pitch?
M8 Bolts/Nuts, are they a 1 or 1.25 pitch?
M10 Nuts, are they a 1, 1.25 or 1.5 pitch?
 

69ST

Well-Known Member
FWIW...it's really not as much of a hassle as you might fear. There are only two different thread pitches used, most are the "standard" pitch for their diameter and very few M10s. From memory, the K1-`79 folding bar clamp uses the coarser thread pitch and the hex nuts are an odd size. The M8 hub-to-wheel hex nuts have the typical thread pitch used with M8s but, the hex nut diameter is 14mm, instead of the normal 12mm. The kickstand pivot bolt nut is an odd size, too...but a standard thread. The seat hinge pivot bolt is a proprietary fastener but, the M6 hex nut is garden-variety 1.0 pitch. Lever pivot bolts are proprietary but, you could use bushings, or a little creative lathe work (depending on the specific bar/level combo) to adapt stainless.

You only have to deal with a few oddballs. The highly-visible fasteners...upper engine guard, plug guard, tank bracket, battery carrier, tail light bracket, seat hinge, seat latch, headlight, wheels...as well as most of the not-so-visible...fenders, footrest bar, speedo, are all garden-variety M6 & M8s.

Engine screws are all M6/1.0, except the semiauto clutch adjuster nut, which is the same as the wheel-to-hub nuts. No reason why you can't use an M8, 12mm, hex instead...it might look a little small but, once you're going to all allens who's gonna complain?:34:
 

Dezdan

Well-Known Member
FWIW...it's really not as much of a hassle as you might fear. There are only two different thread pitches used...
So what I hear you saying, is that I should pick one and use an impact to install it, it shall self thread? :zonked:

...most are the "standard" pitch for their diameter and very few M10s. From memory, the K1-`79 folding bar clamp uses the coarser thread pitch and the hex nuts are an odd size. The M8 hub-to-wheel hex nuts have the typical thread pitch used with M8s but, the hex nut diameter is 14mm, instead of the normal 12mm. The kickstand pivot bolt nut is an odd size, too...but a standard thread. The seat hinge pivot bolt is a proprietary fastener but, the M6 hex nut is garden-variety 1.0 pitch. Lever pivot bolts are proprietary but, you could use bushings, or a little creative lathe work (depending on the specific bar/level combo) to adapt stainless.

You only have to deal with a few oddballs. The highly-visible fasteners...upper engine guard, plug guard, tank bracket, battery carrier, tail light bracket, seat hinge, seat latch, headlight, wheels...as well as most of the not-so-visible...fenders, footrest bar, speedo, are all garden-variety M6 & M8s.

Engine screws are all M6/1.0, except the semiauto clutch adjuster nut, which is the same as the wheel-to-hub nuts. No reason why you can't use an M8, 12mm, hex instead.
Wow! Thanks for the info! My issue is I'm starting with a frame that is basically bare, and so I don't have everything yet that I am building on.

...it might look a little small but, once you're going to all allens who's gonna complain?:34:
Problem I am having, is that I cannot find Black Oxide 18/8 SS socket head cap screws in metric! I can find buttloads of SAE, but no metric! McMaster, Albany County, Grainger have notta. I might end up having to order standard SS ones and bluing them....
 

kirrbby

Well-Known Member
As far as the bolts, I think you'll come very close if you buy the "standard" pitch on everything. I think fine threads are few and far between. It might be only the special bolts that are fine thread, the stuff that has to be from Honda anyway. Fork sealing bolts, steering cap nut etc. It'll be tough to come up with a perfect list and get every single nut and washer blued on the first go round.

--I have a Honda parts manual for a HK1 that I think might call out the thread pitch. I'll go thru it when I'm able and look for odd screws. That's IF it does call out the threads.
 
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69ST

Well-Known Member
Except for the two seat hinge bolts, everything else that threads into the frame, itself, is standard M6/1.0. Use an impact gun to recut the threads at your own risk :butcher: the results won't be pretty. Kirrbby restated it accurately; the fasteners with an atypical pitch are few & far between.

As for being able to source any fastener in any size, thread pitch, alloy and finish...ain't gonna happen, unless you're willing to invest kilobucks and a lot of time. When it comes to the metric system, the US is at least 50 years behind the rest of the world. You might try Brafasco (I believe that they've completely retreated to Canada but will export) and Metrics Unlimited. You're still going to find huge gaps in the listings. Try finding SS acorn nuts, for instance.:26:And, there are a number of proprietary fasteners, such as the upper engine mount & barrel nut, rear muffler hanger stud/nut, steering stem nuts, rear brake shoulder bolts and few others.

Best suggestion I can offer is to approach this as a multistage process and be flexible. That might mean settling for non-stainless to get your desired black oxide finish. You're starting with a bare frame and going non-stock. IMHO, expecting to get everything you want, let alone go through the project in one full sweep, is unrealistic. I've been navigating the custom fastener market for close to 40 years, now; there's been a zero-compromise project.
 

Dezdan

Well-Known Member
As for being able to source any fastener in any size, thread pitch, alloy and finish...ain't gonna happen, unless you're willing to invest kilobucks and a lot of time. When it comes to the metric system, the US is at least 50 years behind the rest of the world. You might try Brafasco (I believe that they've completely retreated to Canada but will export) and Metrics Unlimited. You're still going to find huge gaps in the listings.
True. I hadn't realized Brafasco had moved out... I've searched world wide now, and I am unable to find BO/SS in metric. I'm beginning to believe they aren't manufactured.

Try finding SS acorn nuts, for instance.:26:
Easy :15: http://www.mcmaster.com/#acorn-nuts/=11jckys

And, there are a number of proprietary fasteners, such as the upper engine mount & barrel nut, rear muffler hanger stud/nut, steering stem nuts, rear brake shoulder bolts and few others.
I've been working some of these, gotten close, and still researching.

Best suggestion I can offer is to approach this as a multistage process and be flexible. That might mean settling for non-stainless to get your desired black oxide finish. You're starting with a bare frame and going non-stock. IMHO, expecting to get everything you want, let alone go through the project in one full sweep, is unrealistic. I've been navigating the custom fastener market for close to 40 years, now; there's been a zero-compromise project.
Step by step is probably how it is going to have to go. Now I just need to decide if I want to order bolt by bolt and blue everything, or if I want to just order a bolt 'kit' off of ebay and then blue...
 

nyct70k0

Member
One place I've had good luck with is www.boltdepot.com another place I used to deal with was Metric Multistandard in Hawthorne, NY besides metric fasteners they also used to stock British Standard Whitworth fasteners and tools. When I worked in area I used to go there all the time, the counter people were always helpful especially when I was trying to find some crazy British sized bolt.
 
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