Hi Guys,

Can anyone tell me what this thread is? Its definitely tapered (measures 10.3 mm at root and 9.9 at the 'tip' ) and is 10mm long (if that matters!). It came from the inlet manifold of a 1993 Vx red top engine, and I need to tap a hole in my new bike carb inlet manifold for it to go in, as an air bleed....


Description
My guess is that its an imperial tapered thingy... if my lathe screwcut, I'd make one with a straight metric thread, but it doesn't, and to be honest, even if it did, I couldn't! So if anyone could identify it so I can get a tap, that would be great, even better if someone wanted to lend me the right tap that would be brill!

Thanks

Chris

as far as i know, shouldn't it be metric? with it being from a vauxhall...

Well, thats ^^^ what I'd have thought, but it doesn't seem to match any of the metric stuff I've got - perhaps that's because its tapered....?

Chris

1/8" BSP is 28tpi

1/8" NPT is 27tpi

I suspect it's one or other.


HTH
Paul G

it looks like fuel fitting so my money is on 1/8 nptf (I would need to look in the book to confirm)

Nominal Diameter Major Diameter
mm Tapping
Drill Size
mm TPI Pitch
mm

1/8" NPTF 10,217 8,25 27 0,940
1/4" NPTF 13,577 10,70 18 1,411

[Edited on 1/5/08 by 02GF74]

If it's 1/8"npt most cheapo tap/die sets seem to have one in...

if it's 1/4"npt let me know... I bought one recently for my Pinto water temp sender and they aint cheap so save yourself some money...

(will be at stoneliegh on monday if you want me to bring it along)

[Edited on 1-5-08 by DaveFJ]

Great, thanks guys, the consensus seems to be 1/8 NPT, so I'll go and find the appropriate tap.

Thanks

Chris

A decent set of thread gauges cost peanuts and should be in everyones tool kit. Use mine several times a week.