Quota Oil drain plug size

[Lesman]

I had my oil pan powder coated. There is power coating on the edge of the threads. I need to buy a tap to chase the threads.
The oil drain plug threads measure 19.89mm with a 1.5 pitch. Do I need a 20mm x 1.5 or a 19mm x1.5 tap  to chase the threads? All my existing taps end at 12mm. Normally I would just buy both. I really see no chance of using these taps again.
What is the size of oil drain plug?


Best Regards,
Les

[Chuck in Indiana]

The oil drain plug threads measure 19.89mm with a 1.5 pitch. Do I need a 20mm x 1.5 or a 19mm x1.5 tap

Being a cheap Guzzi guy.. I'd probably use a die grinder, grind flutes in the end of an old drain plug and use that for a thread cleaner. That sounds like an *expensive* tap.

For sure, though, if the threads measure 19.89, you need an M20 tap.

[Howard R]

A couple of ideas.  The thread is definitely M20, which is a common size for automotive plugs on things like differential housings.  You can find a new plug pretty easily on the shelf at most auto parts stores.  They are commonly in the "Help" replacement parts section, or maybe over by the gear oil.  If the powder is only on the outer end of the threaded hole, you might be able to run a plug through from the inside to clear the threads.  Also, you can use any of your existing 1.5 pitch taps as an improvised thread file, engage the threads and work the tap around the circumference by hand.  Could save you the price (Guzzi content ) of a tap you will likely not need again.

Howard

[twhitaker]

A local machine shop, tool & die shop, or automotive repair shop might let you borrow a tap. Take the pan with you and they might do it for you.

[Lesman]

Thanks for the Help. I'm will be buying the Tap on Amazon. I should be getting it tomorrow.
The Quota is down for powdercoating/maintenance. The oil pan came out great except for this problem. A buddy welded 4 aluminum spacers on the bottom of oil pan for a future skidplate(idea was stoen from a BMW GSPD build. I had the front Timing Cover(off to fix an oil leak) and Oil Pan done in Flat Black Wrinkle Finish.

[rodekyll]

Cut a slot lengthwise through the threads of any 1.5 screw (bolt) and use it to pick out any powder.  But really -- it shouldn't be an issue to simply clean the threads up with the existing drain plug.

[Lesman]

Got the tap Saturday afternoon. Threads were cleaned in 2 quick passes. Found a 1" pad (a buddy had the pad and removed the PC for me)to remove the PC off the machined area for the oil  drain plug. Haven't had the time to put every thing back together. I also powdercoated the front timing chain cover. It was off to fix a leaking gasket. 

I appreciate the help.


Les