Husqvarna 3120 technical detail needed

jackumac · Mar 17, 2006

Am looking for the thread pitch and diameter measurement for the clutch side of the 3120 saw. A looking for left hand metric nut for a project i will post an image of when done.

Grease monkey · Mar 18, 2006

Metric Thread size!

If you have acsess to a caliper or micrometer measure the diameter over the threads, now multiply that number by 25.4 as an example with a measurement of .511 x 25.4 you end up with 13mm. .551 x 25.4 = 14mm and so on. Now thread pitch is the width between the thread crown wich is the top of each thread, measure that with the other jaws of the caliper. .039 for 1mm pitch .059 for 1.5 and so on I hope that helps you out with your question cant wait for the project unvieling!

jackumac · Mar 22, 2006

Thanks for the tip greasemonkey, guess i should have known how to do that sort of middle school math on my own. came up with 12mm and 1.25 pitch. Ordered a tap from mcmaster carr and it came a day later and appears to be correct. wow, what excellent service. Will have to make a nut from a bolt head or some steel stock. Image of the project soon. it does use two 3120 engines however.

Lakeside53 · Mar 22, 2006

jackumac said:
Thanks for the tip greasemonkey, guess i should have known how to do that sort of middle school math on my own. came up with 12mm and 1.25 pitch. Ordered a tap from mcmaster carr and it came a day later and appears to be correct. wow, what excellent service. Will have to make a nut from a bolt head or some steel stock. Image of the project soon. it does use two 3120 engines however.

You could just buy the left hand nut from a husky or stihl dealer - very common type...

Grease monkey · Mar 22, 2006

Nuts!

Mcmaster carr would also handle thet nuts unless you need a custom one made up, longer shorter or anything out of the ordinary. I have some interesting ideas for this motor you are making that fit the minnesota climate!