7/16 x 24tpi tap availability?
Turbo Mini Forums

anyone know where i can source one of these from? need to run a tap down my turbo oil feed cos it keeps knackering my banjo bolts. plus i want to be sure it is the right thread.

just phoned up supposedly the largest tap & die supplier in europe and apparently that size doesn't exist, he said i meant 20tpi so i politely ended the call.

going to give cromwell tools a bash later if i can find any of their branches still open. used to be one round the corner but they closed it :(

fook, just got off the phone to cromwell, they can get me one ordered in but its £31+vat, and that doesn't come with any KY...

Hi,
I've looked on here and 24tpi is right. I've looked around on the net and at the Goliath tools catalogue ( big place in brum, threading tools is all they do) and I can't find a tap or die :(
Cheers,
Gavin :)

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Hi,
Eek, it should be coated in something for that price!
Cheers,
Gavin :)

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cheers for looking gavin :)

i got a brand spanking turbo but the banjo will go in 3 turns then it knackers the thread and i can't get enough balls behind it to seal properly so it's pissing oil out everywhere still.

need to get the turbo back off and investigate properly. i did get a male>male fitting with it so i'm going to see if that goes in ok and find out the thread of that cos its almost as if the tpi is wrong on the banjo's i've got although they fit fine in the other T2's i've tried them in.

quote from another thread, there are 2 different fittings:

On 24th of Feb, 2006 at 03:49am TurboDave said:
Ben / Wil

Garrett used Imperial on the older genration units (pre GT). I know this - because I have the Garrett drawings for several T2 units...

There are TWO sizes:
7/16 x 24tpi
1/2" x 20tpi

I'm going to say - that if an M12 went in - then you have the rarer 1/2" fitting.


Hence, if he got a union to screw in, then he was probably trying M12x0.75... The metric pitch equiv. of 20tpi is 0.787mm. Only reason it screwed in is beacause the thread is 0.7mm smaller on diameter than the correct one - hence the pitch error is being taken by the radial slop between the male and female thread forms...

Chances are - you'll get away with it... Bear in mind though; it ain't right... Nay; it's a bodge.


Do consider sending a drawing to a machine shop and get them to knock something up that is RIGHT using a decent-grade 1/2" shouldered bolt as a start point (saves money having them mill a hex head onto a piece of bar stock).
Also bear in mind, you will need a 'harder to find' banjo fitting (I assume you're using a banjo?) as this needs to be -4, but be able to take a 1/2" fitting!
I'm 100% sure you won't be able to use the banjo end that was on your T3 pipe - I think the T3 banjo bolt is 7/16 diamter...


So - consider getting a banjo union from the company that will be making your new hose, and drilling it out to 1/2" as an easier option to searching the world for one. Clean it thoroughly, then get your hydraulics place to sort you out a new hose...

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

yeah i'd seen that one but it's definately not a 1/2" fitting, currently got a 7/16x24 in there holding on for dear life.

try wiseman threading tools, I have got some odd tpi stuff from them before for a good proice.

So, have you confirmed that your banjo bolts are 24TPI?

Hang about - didn't you show a picture of your 'new' turbo recently?

If so - show it again. I think you have a GT-series unit.

i ordered 2 new ones from think automotive as i didn't have any when fitting the T2. all it came with was a male>male adaptor but i wanted to use a banjo for ease of clearence.

http://www.turbominis.co.uk/forums/index.php?p=vt&tid=146392


here's a pic.

I am 99% sure the fins are only found on the VERY later T-series, and all GT units.

So, chances are, you need a GT-series fitting - which I recall is metric.

seems about my kind of luck, looks like i better try and find out what metric thread it could be and get hold of a couple of banjo's to try...

any idea what turbo it actually is from the proper sizes i manged to get of the wheel. they don't seem to match up with the ones you posted in the earlier thread.

I bought 12mm 1.25 pitch metric fine banjo to fit my GT series turbo.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

cheers wil, will give one of them a shot :)