Welcome! Please use the navigational links to explore our website.
PartsASAP LogoCompany Logo Auction Link (800) 853-2651

Shop Now

   Allis Chalmers Case Farmall IH Ford 8N,9N,2N Ford
   Ferguson John Deere Massey Ferguson Minn. Moline Oliver

Tractor Talk Discussion Forum

Spark plug thead size

Welcome Guest, Log in or Register
Author 
jd jim a

04-27-2006 22:17:39




Report to Moderator

Am I correct in thinking that spark plugs most commonly come in two thread sizes, 14mm and 18mm? What would the thread pitch be, and what tap would I need to run through the threads of a head that uses a 14mm plug?




[Log in to Reply]   [No Email]
Jim Bruce

04-28-2006 16:57:25




Report to Moderator
 Re: Spark plug thead size in reply to jd jim a, 04-27-2006 22:17:39  
In a pinch, knock the center electrode out of a old plug and use a hacksaw to cut two slots in threads forming an x to make a thread chaser.



[Log in to Reply]  [No Email]
Jim in Mo.

04-28-2006 16:01:53




Report to Moderator
 Re: Spark plug thead size in reply to jd jim a, 04-27-2006 22:17:39  
In a pinch, knock the center electrod out of an old plug and using a hacksaw make two cuts thru the threads at right angles to make a thread chaser.



[Log in to Reply]  [No Email]
Glen in TX

04-28-2006 12:41:40




Report to Moderator
 Re: Spark plug thead size in reply to jd jim a, 04-27-2006 22:17:39  
Yep those are the most common but there were also smaller 10mm and 12mm also. Old 46 Cheverolets and some old Cadillacs used the 10mm plugs.



[Log in to Reply]  [No Email]
Mike M

04-28-2006 08:43:38




Report to Moderator
 Re: Spark plug thead size in reply to jd jim a, 04-27-2006 22:17:39  
What are you working on ? Some of this old iron takes 7/8-18 and 1/2" pipe threads



[Log in to Reply]  [No Email]
KEB

04-28-2006 07:54:27




Report to Moderator
 Re: Spark plug thead size in reply to jd jim a, 04-27-2006 22:17:39  
Use a thread chaser, not a tap. Taps are designed to cut threads, thread chasers are designed to re-form them. If the threads are bad enough you have to use a tap, you"d probably be better off boring it out & putting in a helicoil.

Keith



[Log in to Reply]  [No Email]
Joe (Wa)

04-27-2006 23:29:17




Report to Moderator
 Re: Spark plug thead size in reply to jd jim a, 04-27-2006 22:17:39  
These threadchasers work ok if the existing threads are not too far gone. Take it slow, work it back & fore.

Joe



[Log in to Reply]  [No Email]
Bob

04-27-2006 22:32:29




Report to Moderator
 Re: Spark plug thead size in reply to jd jim a, 04-27-2006 22:17:39  
14 MM X 1.25 pitch

18 MM X 1.5 pitch



[Log in to Reply]  [No Email]
[Options]  [Printer Friendly]  [Posting Help]  [Return to Forum]   [Log in to Reply]

Hop to:


TRACTOR PARTS TRACTOR MANUALS
We sell tractor parts!  We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today. [ About Us ]

Home  |  Forums


Copyright © 1997-2023 Yesterday's Tractor Co.

All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy

TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.

Yesterday's Tractors - Antique Tractor Headquarters

Website Accessibility Policy