FYI the difference between metric and standard hardware

[Which 450?]

I have had a few project bikes over the years, and on every single one, one of the idiots before me jammed a standard bolt in a metric hole. Probably because he had no idea there was a difference. So when I try putting the correct bolt back in, I end up having to retap it in some sort of way by heli-coiling it or welding it in and re drilling and tapping it, or going a size larger. So I thought I would post this little bit of information on the most commonly used types of bolts so people know what bolt to use, in case someone on here has a bike that turns into a project bike for me in the future..

1st off.. Standard bolts, YOU SHOULD NEVER USE THESE ON A QUAD, because there is only metric bolts on a quad, unless, in some cases of aftermarket parts, the part itself might use a standard bolt in the part, and only on the part, ie a end cap of a pipe,

These are the different grades of standard bolts and how to tell....

Basically, you count the tick marks, and add 2, that gives you the grade

If there are no markings, its a grade 2, this is a low stress bolt, should only be used in low stress areas, where no strength is needed
http://www.boltdepot.com/images/catalog/hex-bolt-standard.gif

3 marks, grade 5 medium strength bolt
http://www.boltdepot.com/images/catalog/hex-bolt-standard-grade5.gif

6 marks, grade 8 high strength, if its up to me, this is the only std bolt grade I'd use
http://www.boltdepot.com/images/catalog/hex-bolt-standard-grade8.gif

Then for Metric hardware, this should be the only type of hardware you should put on your quad, They have these at any hardware store (home depot, Lowes) or a fastener supply store (I use a local caterpillar parts store, they got everything, and the bolts say "CAT" on them it's cool.

I cant find any cool pics of metric bolts. But theres 2 common types "8.8" and "10.9" 8.8 is about the same strength as the grade 5 std bolts, and 10.9 is about the same as grade 8 bolts. It will say it right on the head of the bolt just like the std bolts have the tick marks, "8.8" or "10.9"

Now on to thread pitches, FINE and coarse thread, Standards thread pitch is found by the number of teeth per inch, Usually all the bolts in a bike that are wrong are "1/4-20" which is 1/4" diameter and 20 threads per inch. When it should be a "m6x1.0" the threads are similar, but the std 1/4-20 bolt is a slightly larger diameter and the thread pitch is coarser. Right now I cant remember how to find what the thread pitch of metric bolt is but I can remember that the lower the number, the more threads per length.

Any questions, comments, suggestions, or anything to ad?

[CRich[814]]

nice writeup. easy to understand. i never knew about the 0,3,6 line markings.

[300exHONDARIDER]

SAE, or standard threads, are defined as major diameter by threads per inch.
Metric are defined as major diameter by pitch distance. So an M6X1, is 6mm diameter over the threads, by 1mm distance from thread to thread, which is roughly .04 inches.
A 1/4 20 is .25 diameter over the threads by .05 pitch. To figure the pitch on SAE bolts, just divide 1 by threads per inch, and you get the pitch distance.

[embler]

just wanted to add to this. not all quads use metric bolts. polaris quads use standard sized nuts and bolts.

[MTDman11]

polaris is AMERICAN made. Be AMERICAN buy AMERICAN. enough said. when you say only put metic bolts on you quad. do you mean metric threads or metric heads (heads as in like were you put the wrench)

[kraemer]

only metric threaded bolts have metric heads.... as written above CATERPILLAR is great for strength, and have any size you will need on your bike, might have to order and you will pay... but its only a day away...

oh and don't foget, metric threads are more square than standard, they clamp better... and a metric 12.9 is stronger then a grade 8... 10.9 is the same strength as a grade 8

loctite is important in high vibration applications but proper torque specs are important 100% of the time

[craigmacphee]

great thread. You are absolutely right. Loctite everything! Fastenal is a great place to get all the bolts you need. It sucks having to buy in large numbers when you go there, but often times 25, 50, or even 100 of what you need will be cheaper than (5) of what you need bought individually from the hardware store.