Hey guys,

I'm putting a helicoil into a blind hole (i.e. a hole that doesn't go all the way through) in my engine. I have the hole drilled and tapped with the tap that the helicoil kit came with. However, since the helicoil tap is tapered on the end, I can't tap all the way to the bottom of the hole. I know I need a bottoming tap (a tap that isn't tapered), but for the life of me I can't find them anywhere in town. I tried NAPA, Autozone, Advance, Van's, Home Depot, and Lowe's. The closest I came was at NAPA, the guy found the size I need (M12x1.5), but he said NAPA didn't make a bottoming tap in that size. For referece, the Helicoil kit I got is for M10x1.5 and if the manifold bolts. The guy at NAPA tried the tap in various thread finders and we decided the tap is M12x1.5.

Any ideas where I can find a bottoming tap that's M12x1.5?

- Andy

 

make your own. Tap the hole with the tapered tap. Then take a second tap and grind off the tapered lead, making it flat....you will want to leave a SLIGHT taper....maybe two threads of it. Then run this tap into your previously tapped hole.

 

That's not a bad idea. If no one else replies, I may try that. Thanks!

 

http://www.jlindustrial.com/

I order from them all the time. They have good prices also, and provide lots of options for the same type.

 

Just go ahead and grind the point off the tap, you'll be fine.

 

www.msc.com

 

www.mcmaster.com is another decent source.

Baja is spot on - the aerospace machinists I worked with in the past cut down taps on a regular basis when there wasn't a plug tap handy.

Dave

 

Have you looked in the yellow pages under "tools". Im sure you'll have a local tool supplyer that will have one in stock.

 

Just FYI... I just used my dremel and cut down the tap and it worked great. Thanks everyone.