Need a source for pre-1967 JIS thread pitch screws.

[jnbmoore]

Greetings all! Am having problems finding NOS or good used screws that have the old JIS thread pitch. All the stuff I've gotten are ISO thread pitch which won't work in my 1965 Dream. Am especially looking for the screws that hold the points plate to the cylinder head side cover and the screws that hold the points cover over the points. Can anyone help?

[danielzink]

Pretty sure JIS refers to the head - not the thread pitch.

They should be standard metric thread.



https://en.wikipedia.org/wiki/List_of_s ... JIS_B_1012



Dan

[G-Man]

Those points cover screws are M5 with a JIS thread pitch. I had touble finding the ones for the points cover so helicoiled the holes so that I could use ISO metric screws.

I've heard that McMaster Carr do some JIS screws.

https://www.mcmaster.com/#jis-(japanese ... s/=1efbumi

thread pitch-

newISO - oldJIS
3mm-.5-.6
4mm-.7-.75
5mm-.8-.9
6mm-1.0-1.0
8mm-1.25-1.0
10mm-1.5-1.25
12mm-1.75-1.5


G

Greetings all! Am having problems finding NOS or good used screws that have the old JIS thread pitch. All the stuff I've gotten are ISO thread pitch which won't work in my 1965 Dream. Am especially looking for the screws that hold the points plate to the cylinder head side cover and the screws that hold the points cover over the points. Can anyone help?

[Seadog]

Search ebay (or Google) by Honda part number. It’s 93700-05030. There are 4 or 5 options on ebay, all a bit costly. See https://www.ebay.com/itm/New-OEM-Honda- ... 2664!US!-1

[brewsky]

If you drill down on the individual item spec on Mc Master Carr, it shows .8 pitch for the 5mm screws, so just because they say JIS, doesn't mean "old" JIS.

Evidently, JIS still lives on even though it adopted some (or all?) of the ISO standards in '67.

I have ordered honda part numbers for old JIS screws from honda dealers and received screws marked with the correct part #, but with "new" thread pitch, and no superseded number

[Tim Allman]

If you drill down on the individual item spec on Mc Master Carr, it shows .8 pitch for the 5mm screws, so just because they say JIS, doesn't mean "old" JIS.

Evidently, JIS still lives on even though it adopted some (or all?) of the ISO standards in '67.

I have ordered honda part numbers for old JIS screws from honda dealers and received screws marked with the correct part #, but with "new" thread pitch, and no superseded number

You're right about this. In the Honda Service Bulletin that covers the change they refer to new and old JIS. Usually we want fasteners made to the old standard.

As an aside, I have a tap and die set that covers all of the old thread pitches. If I could find screws that haven't been threaded, I could cut my own as needed. Does anyone know of a source for such a thing?

[brewsky]

If you drill down on the individual item spec on Mc Master Carr, it shows .8 pitch for the 5mm screws, so just because they say JIS, doesn't mean "old" JIS.

Evidently, JIS still lives on even though it adopted some (or all?) of the ISO standards in '67.

I have ordered honda part numbers for old JIS screws from honda dealers and received screws marked with the correct part #, but with "new" thread pitch, and no superseded number

You're right about this. In the Honda Service Bulletin that covers the change they refer to new and old JIS. Usually we want fasteners made to the old standard.

As an aside, I have a tap and die set that covers all of the old thread pitches. If I could find screws that haven't been threaded, I could cut my own as needed. Does anyone know of a source for such a thing?

Maybe obtain some longer length shoulder screws and cut the threaded portion off?