18 mm spark plug thread pitch

[P.A.G.]

Anyone know what the thread pitch is for the standard 18mm spark plugs?

[INLINE4NUT]

Buy a pitch gauge they work wonderful

[P.A.G.]

Originally posted by INLINE4NUT
Buy a pitch gauge they work wonderful

I was looking for information not a smart ass answer. My threads are so bad that I can't read them with a gauge which by the way I already have.

[INLINE4NUT]

I wasnt trying to be a smartass but they do work well and a chart comes with most of them,sorry if you were offended,also I believe off the top of my head its, standard 2.5 or JIS 1.5

[P.A.G.]

Originally posted by INLINE4NUT
I wasnt trying to be a smartass but they do work well and a chart comes with most of them,sorry if you were offended,also I believe off the top of my head its, standard 2.5 or JIS 1.5

Oops sorry, I got a little defensive. I get the feeling from some of the other posts that I'm not well liked here. Sorry

[INLINE4NUT]

NP, I dont take offense to to much good luck!

[41knuck]

My machinery handbook says 18mm x 1.5

[Paps]

The machinist Handbook is a great reference but when you are working with Harley Davidson you really do need the thread pitch gauges. Harley Davidson has a long history of a habit of creating ******* threads out of many a standard diameter on their parts and fasteners. Paps

[P.A.G.]

Originally posted by Paps
The machinist Handbook is a great reference but when you are working with Harley Davidson you really do need the thread pitch gauges. Harley Davidson has a long history of a habit of creating ******* threads out of many a standard diameter on their parts and fasteners. Paps

Yeah it's called Harley-davidson standard. I don't know exactly why they needed to create their own thread standard but it realy throws you a curve when you are trying to finds nuts and bolts for a project. BTW I found out that the thread pitch for the 18mm spark plugs are 1.5mm.

[Paps]

I noticed my responce to the topic with the correct term I used for the odd ball threads was edited. For those who didn't see this correct term it is [ B A S T A R D ]. This term will be found in the machinists handbook. It is not a curse word. When used to describe a female dog there is another word [ B I T C H ]. It is in the dictionary. It will probably be edited here also. LOL. I beleive Harley Davidson may have felt the need to engineer some diameters, lengths, and strengths around the thread pitches to accomodate the necessary functions and needs of a particular component or components. This is not a rare proceedure in the manufacturing industry. I have seen many a LOL word thread used on many an application throughout my career as a tool maker machinist in heavy industry. I have even seen this thread used in double and triple leads. For those of you who never heard of these screw threads, the double and triple leads screw threads are self explainatory. Instead of just one continuous thread running the distance or length of a fastener, etc., there is two or three threads running the same lengths. Boy are these threads fun to chase !! Paps

[AdminGuy]

I couldn't stop laughing when I read that! So, happy new year. I'm flexible - no big deal.

pussy, bitch, bastard are off the censor list. Context is everything.

Any specific examples of the double treaded HD bolts someone could point out? I'm curious.

[Kojack]

I'm not sure that Paps meant that Harley used double and triple lead threads, just that they exist. They're most often used in applications where the thread needs to transmit motion quickly. A good example is a valve (as in water valve) stem thread. In an ironic twist, I worked as a machinist for over 20 years. I chased a lot of multiple lead threads. Recently the company cut back and I was moved from maintenance to an operations job. Now I spend part of my workday operating the valves I used to repair. Weird.

[Paps]

Ha! Ha! Ha! LOL!!! I didn't even think of the cat oximoron (sp). I don't know of any multiple lead screw threads on any HD component either. Kojack was correct in his understanding of what I was trying to say. I just pointed those threads out as a comparison for different thread applications to better understand the seem to be odd thread choices HD uses and why they may have chosen to use such thread pitches. Kojack presented a great reference for one of the multiple lead thread uses. Paps

[AdminGuy]

pheeeewww... good. Now I can stop racking my brain.