What do the numbers in bolt measurements refer to?

For example, BOLT, FLANGE (10X20) and BOLT, FLANGE (10X35)?

If I needed to get a nut for these bolts, what would be the nut size?
In other words, how do I know the diameter of the bolt?

And what do these numbers mean when it comes to washers, WASHER, SPECIAL (11X24)?

Thank you.

 

Second number is the length of the bolt. First number is the threading. Im going to put another question there for the length, is the length measured to the bottom of the flange or the overal length of the fastener?

 

For the bolts, it is width x length of the threaded part, in mm. Unfortunately, it tells you nothing about thread pitch nor bolt head size.

As for washers ... you've got me. Don't know either.

 

Thanks for the info. Is there a way to know what size nut to use with these bolts?

 

nuts will have the same measurement. problem is the head size isn't the same between different manufacturers.

 

So for the 10x35 bolt, what nut do I need?

 

a 10mm by whatever thread pitch you have.

 

Some info:


https://honda-tech.com/forums/tech-misc-15/make-up-part-numbers-2048988/