JIS screw ?

[Iahawk]

finally started up the 42 year old Nighthawk 650 this morning to go for the inaugural ride of 2026. She's cold blooded to begin with...and especially so after sitting for 6 months with empty carb bowls. Finally got her started (after I'd pushed her back in her parking spot in order to hook up the battery tender to recharge the mostly depleted battery).

Went for a nice hour long ride this morning.

This afternoon I pulled out the K&N air filter for its annual cleaning and reoiling. (I'd prefer a paper pleated filter but they are no longer available for this bike).

I noticed these screws for the airbox door. They are JIS screws with the little dot but they also have a + sign stamped in them. Has anyone seen these before? Wonder what it means? Both Philips and JIS driver will work??

[Stig / Major Tom]

I don't know that screw Hawk but I do remember nearly stripping the tight little screw heads on the brake fluid reservoir of my Honda Forza. I'd used a philips.
Then I bought some replacement screws AND a set of JIS screw drivers!
No problems after that!
Stig

[Stig / Major Tom]

[Iahawk]

yep, it's JIS for sure, but what is the additional + stamped into the screw head opposite the JIS dimple?

[Ruffus]

..hawk, deep down in my engineers brain was a memory put there maybe 50 years ago.

Q:
...could it be that this screws have been changed once against aircraft bolts, because as far as I remember, JIS bolts and screws particularely approved for use at aircrafts had signs like that on their heads. We could not use them for they didn't match with DIN. Not only crosses but others with significant meaning.