Racetech RD107 Bolt - Exhaust Manifold
Racetech RD107 Bolt - Exhaust Manifold
Author
Discussion

s p a c e m a n

Original Poster:

12,102 posts

178 months

Tuesday 13th May 2014
quotequote all
These ones

I'm not old enough to figure out imperial without googling and I'm not entirely certain what all of these measurements are so I might as well just ask here, I normally walk in somewhere with the bolt I want and ask for a few of them biggrin

What size head has this bolt got in mm please?

3/8x1x16 UNC

brett84

1,291 posts

183 months

Tuesday 13th May 2014
quotequote all
Don't know if it helps but standard are 14mm

davelittlewood

312 posts

163 months

Tuesday 13th May 2014
quotequote all
Standard head size is 9/16" AF ->14.28mm.

A loose 14mm spanner might fit but best to go and buy a set of imperial spanners/sockets

phazed

22,500 posts

234 months

Tuesday 13th May 2014
quotequote all
EBay is ideal for a basic set of imperial spanners and sockets..

Go for Draper or similar.

s p a c e m a n

Original Poster:

12,102 posts

178 months

Tuesday 13th May 2014
quotequote all
Yeah, I've got a box full of 14mm head ones but I thought I heard that the originals were smaller. What does the 3/8 bit in that refer to then, I guess it's not the head size?

Anyone got any thoughts on fitting a set of 13mm ones to give more of a turn with a spanner on some and maybe be able to get a ring on the really close ones, would I be more likely to round a head or something if they were smaller?

Richard 858

1,882 posts

165 months

Tuesday 13th May 2014
quotequote all
The 3/8" refers to the diameter of the bolt shaft before the thread is turned into it, as in metric bolt sizes i.e an M8 (8mm) bolt will typically have a 13mm head. other numbers refer to thread pitch (coarseness) and length. I'm no expert but this is what I understand. Hope this helps.

AV8

363 posts

209 months

Tuesday 13th May 2014
quotequote all
3/8x1x16 UNC

3/8" outside diameter x 1" long x 16 threads per inch UNC = Unified Coarse which btw is American and not Imperial.

jojackson4

3,049 posts

167 months

Tuesday 13th May 2014
quotequote all
Come on space man get some imp spaners
The metric one just don't fit

fatboychim

979 posts

281 months

Wednesday 14th May 2014
quotequote all
If you're replacing I would go for these

http://www.actproducts.co.uk/shop/ms17b-arp-bolts-...

Not only do they not come undone on their own, ( although 1 or 2 people have reported them coming loose) they have a smaller head size (3/8 IIRC)and are therefore easier to get a spanner on

spend

12,581 posts

281 months

Wednesday 14th May 2014
quotequote all
AV8 said:
... Unified Coarse which btw is American and not Imperial.
WTF is imperial then?

Most will class all threads based on the imperial unit (an inch) whether British / American / Japanese... IME.


OP typically spanner size for plain hex 3/8UNC is 9/16" AF.

EggsBenedict

1,795 posts

204 months

Wednesday 14th May 2014
quotequote all
people usually refer to AF as 'imperial', but think UNC, AF and UNF will all be turned with an 'imperial' socket set, as the inch that we use and the yanks use is the same thing. As someone alluded to, the metric sockets are not equivalent and slop on the socket gripping the nut will cause the nut to round off.

However, there are socket sets that grip on the flats that claim to turn either metric or 'imperial' bolts.

The other thing is whitworth - i've got those as i've got an old bike and had an old landy - they don't fit anything else smile.

ianwayne

8,549 posts

298 months

Wednesday 14th May 2014
quotequote all
Some sizes are so close you can use either though. I discovered this with wheelnuts. 3/4" is 19.05mm. I've used either on some very tight wheelnuts without a problem.

Similarly, 1 1/16" is 26.99mm. Oil filter housing on my little diesel car is 27mm but can use either.




fatboychim

979 posts

281 months

Wednesday 14th May 2014
quotequote all
jojackson4 said:
Come on space man get some imp spaners
The metric one just don't fit
Are they like really small spanners for working on rear engine cars? biggrin

AV8

363 posts

209 months

Wednesday 14th May 2014
quotequote all
spend said:
WTF is imperial then?

Most will class all threads based on the imperial unit (an inch) whether British / American / Japanese... IME.


OP typically spanner size for plain hex 3/8UNC is 9/16" AF.
Imperial is British, ie BSW ( British Standard Whitworth), BSF (British Standard Fine), BA (British Association), BSP (Brithsh Standard Pipe) etc...

UNF and UNC are American.

As the Rover block is of American origin it has UNF and UNC.

jojackson4

3,049 posts

167 months

Wednesday 14th May 2014
quotequote all
fatboychim said:
jojackson4 said:
Come on space man get some imp spaners
The metric one just don't fit
Are they like really small spanners for working on rear engine cars? biggrin
I can just remember them , justlaugh

spend

12,581 posts

281 months

Wednesday 14th May 2014
quotequote all
AV8 said:
spend said:
WTF is imperial then?

Most will class all threads based on the imperial unit (an inch) whether British / American / Japanese... IME.


OP typically spanner size for plain hex 3/8UNC is 9/16" AF.
Imperial is British, ie BSW ( British Standard Whitworth), BSF (British Standard Fine), BA (British Association), BSP (Brithsh Standard Pipe) etc...

UNF and UNC are American.

As the Rover block is of American origin it has UNF and UNC.
You sound like a frog... they also like making up their own standards wink

AV8

363 posts

209 months

Wednesday 14th May 2014
quotequote all
spend said:
You sound like a frog... they also like making up their own standards wink
Your right, they did make up their own. Theirs is called Metric.

Me, I'm not a frog, but about 20 years ago I served a 4 year apprenticeship in mechanical engineering, then went back to college and did a 3 year degree course.
Industrial plant and machinery in those days was a mixture of Metric, imperial, American and whatever else you might just come across.

s p a c e m a n

Original Poster:

12,102 posts

178 months

Wednesday 14th May 2014
quotequote all
rofl

I only wanted to know if the bolts I bought off of Racetech were advertised as having 14mm heads, because they have and I thought they were going to be smaller irked

Carry on people, I've learnt a few random things from this thread and it's supplied a couple of giggles hehe

jojackson4

3,049 posts

167 months

Wednesday 14th May 2014
quotequote all
jojackson4 said:
fatboychim said:
jojackson4 said:
Come on space man get some imp spaners
The metric one just don't fit
Are they like really small spanners for working on rear engine cars? biggrin
I can just remember them , justlaugh


Not much good for manifoldsjester

davelittlewood

312 posts

163 months

Thursday 15th May 2014
quotequote all
AF = Across Flats.

AV8 is correct, UNC and UNF are ASME standards (American Society of Mechanical Engineers).


When we sell steam turbines to the USA we have to use ASME threads on everything including the lifting eye bolts (guarantee that someone would manage to get a AMSE thread lifting bolt into a metric hole only to drop 40 tonnes of turbine casing on someone as the thread strips out...angel)