[Diy_efi] Tapping Metric Injector Threads

[Martin, Sam]

Brian wrote:
> I've got a Bosch CIS injector, 0 437 502 047
> It has an M12x1.5 metric thread.  That's 12mm major diameter
> with 1.5mm pitch.
> 
> I bought a tap from MSC that I thought was supposed to be
> tapered.  I tapped some scrap metal, and the injector screws 
> into it with a very loose sloppy fit.  I will try a smaller 
> drill bit size, but I don't think that's going to help.
> 
> Does anyone know if there exists such a tapered tap, like for
> NTP, except metric?

Brian,
	Are you sure the tap you bought is for tapered threads? Looking at
the MSC catalog, they refer to what is commonly known as a starting tap as a
tapered tap. These are used to start threads in a drilled hole. If the hole
is not blind, these can thread all the way through a piece of material. If
the hole is blind you would start with this and finish with a plug tap and
then a bottoming tap to cut threads to the bottom of the hole. The *taper*
in the name only refers to the starting edge of the tap. The final cut
treads will not be tapered as in NPT.

BTW, when you cut tapered threads with a tap such as a NPT tap, you have to
leave (I think) 5 or so of the taps threads exposed above the material.

I would call these guys: http://www.newmantools.com/tapdie.htm#taps
>From their website, it looks like they might be able to get what you need...

TapMagic is the best cutting fluid I've ever used.

Sam

_______________________________________________
Diy_efi mailing list
Diy_efi at diy-efi.org
http://www.diy-efi.org/mailman/listinfo/diy_efi