Ducati Monster Forum

Moto Board => Tech => Topic started by: He Man on October 14, 2009, 03:49:32 PM

Title: Measuring bolts
Post by: He Man on October 14, 2009, 03:49:32 PM
Does a M5x10 bolt mean there is 10mm worth of thread, or its 10mm long (including head)
Title: Re: Measuring bolts
Post by: Speeddog on October 14, 2009, 03:52:08 PM
It means there's 10mm of shank on the bolt.

Unless it's a flat-head bolt or screw, then it's the overall length.
Title: Re: Measuring bolts
Post by: He Man on October 14, 2009, 04:06:53 PM
gotcha thanks. I have a flat head bolt for the kickstand mount to engine that needs to be replaced. so ill buy overall length. thanks
Title: Re: Measuring bolts
Post by: Speeddog on October 14, 2009, 04:38:57 PM
Just to be clear, this is what I mean by a flat-head bolt:

(http://www.mcmaster.com/param/images/scs/alloyflatfull.gif)
Title: Re: Measuring bolts
Post by: He Man on October 14, 2009, 04:48:11 PM
Quote from: Speeddog on October 14, 2009, 04:38:57 PM
Just to be clear, this is what I mean by a flat-head bolt:

(http://www.mcmaster.com/param/images/scs/alloyflatfull.gif)

OH. I got that one wrong. I Guess thats why the bolt guage has that shape wedged into it!
Title: Re: Measuring bolts
Post by: DucHead on October 14, 2009, 05:57:50 PM
They're also called "countersink" bolts.
Title: Re: Measuring bolts
Post by: junior varsity on October 28, 2009, 04:42:16 PM
The simple way to think about it is the threaded diameter is 5mm on an M5, and the threaded length is 10mm on an M5x10.

A not so sure way to guess at the bolt size without removing one, is to go up one 'size' from the hex wrench you'd use on it. A M5 bolt (non buttonhead mind you) usually takes a 4mm allen wrench. An M8 takes a 6 usually, and so on (m6->5, and on and on)
Title: Re: Measuring bolts
Post by: ducpainter on October 28, 2009, 04:48:06 PM
Quote from: ato memphis on October 28, 2009, 04:42:16 PM
The simple way to think about it is the threaded diameter is 5mm on an M5, and the threaded length is 10mm on an M5x10.

A not so sure way to guess at the bolt size without removing one, is to go up one 'size' from the hex wrench you'd use on it. A M5 bolt (non buttonhead mind you) usually takes a 4mm allen wrench. An M8 takes a 6 usually, and so on (m6->5, and on and on)
Good tip...

but that doesn't address pitch. ;)
Title: Re: Measuring bolts
Post by: junior varsity on October 28, 2009, 06:21:40 PM
True. For that, its time to consult the manual. Small diameter are .8, intermediate are 1.0, big are 1.25.  ;) (most of the time)

button head bolts use a much smaller allen wrench than the tip i gave earlier indicates, so on that one, you just have to suck it up, pull and measure, if you are ordering new stainless, alu, or ti.
Title: Re: Measuring bolts
Post by: Speeddog on October 29, 2009, 07:57:29 AM
Generally,

4x0.7
5x0.8
6x1.0
8x1.25
10x1.50

Not sure if Ducati uses 10x1.25, those are fairly common as well.

Title: Re: Measuring bolts
Post by: junior varsity on October 29, 2009, 08:01:05 AM
I know I can check, because I ordered the wrong size Ti bolts one time (wrong thread pitch) - It was for something big too, like M8's for caliper bolts or M10 for rearset/sidestand/case bolt...
Title: Re: Measuring bolts
Post by: Raux on October 29, 2009, 09:57:59 PM
THread chart
http://www.boltdepot.com/fastener-information/Printable-Tools/Metric-Hex-Bolt-Sizes.pdf (http://www.boltdepot.com/fastener-information/Printable-Tools/Metric-Hex-Bolt-Sizes.pdf)

and fastener type chart
http://www.boltdepot.com/fastener-information/Printable-Tools/Type-Chart.pdf (http://www.boltdepot.com/fastener-information/Printable-Tools/Type-Chart.pdf)

and a ruler with a gauge
http://www.boltdepot.com/thread-gauges.aspx (http://www.boltdepot.com/thread-gauges.aspx)

Title: Re: Measuring bolts
Post by: junior varsity on October 30, 2009, 07:21:34 AM
For the US guys, we now have a Probolt-Usa website, which I am thrilled about. Also check out racebolts.com, ballerbolts.com, and I use boltdepot above occasionally as well.