UNC or UNF threads on my Ford 2722?

[Puggy]

Hi all,

I need to get a selection of nuts and bolts as spares as my 1984 Ford 2722 engine is all imperial (or American anyway!). I have spanners and sockets etc, but I am not sure whether I have UNC or UNF threads? Does anyone know or know how I measure a bolt to see??

Thanks

Puggy

 

[macd]

Wiki will tell you more than you'll ever need to know. A thread gauge would be a cheap and worthwhile investment.

 

[VicS]

Hi all,

I need to get a selection of nuts and bolts as spares as my 1984 Ford 2722 engine is all imperial (or American anyway!). I have spanners and sockets etc, but I am not sure whether I have UNC or UNF threads? Does anyone know or know how I measure a bolt to see??

Thanks

Puggy

If bolt heads and nuts are exact fractions of an inch across the flats and the spanner similarly marked ( Ie 1/4" 5/16" 3/8" 7/16" etc) they will be either UNC or UNF but you may have both.

You can tell them apart by measuring the thread pitch and referring to a thread table.

 

[doug748]

As macd.

I bought a cheap thread gauge from a cheapo tool shop it is fine. Get one that does metric and Imperial for about a fiver:

First - measure the bolt dia across the threads - this will not be exact to a sparrow's fart but will allow you to deduce the nominal size.

Second - Apply your thread gauge till it matches up, that will give you the TPI.

Done.

I know nothing of Ford engines. General engineering practice dictates that a mixture of UNC / UNF will be used, depending on the application within the motor.

 

[Puggy]

thanks for all your help and the very useful thread table. Doug748 - I think you are right and there is probably a mixture, so I will get a selection of both, as well as a thread gauge.

 

[rob2]

The general priciple, although I'm sure you'll find exceptions, is that coarse threads are used into castings to spread the load whereas fine threads are used where a nut is fitted, or the hole is tapped into steel (not iron). For an emergency spares pack, screws are probably more adaptable as it eliminates the problem of having the correct length of unthreaded bolt for the purpose, but where a bolt should be used the screw should be replaced ASAP as the thread might long-term cause some damage within the component - advice many of us know but frequently ignore!

Rob.

 

[VicS]

p and the very useful thread table.

have a metric one to go with it

 

[davidej]

The general priciple, although I'm sure you'll find exceptions, is that coarse threads are used into castings to spread the load whereas fine threads are used where a nut is fitted, or the hole is tapped into steel (not iron). For an emergency spares pack, screws are probably more adaptable as it eliminates the problem of having the correct length of unthreaded bolt for the purpose, but where a bolt should be used the screw should be replaced ASAP as the thread might long-term cause some damage within the component - advice many of us know but frequently ignore!

Rob.

I am sure you mean machine screw (ie a bolt threaded right up to the head) not a wood screw

The OP might not realise this

 

[Heckler]

Hi all,

I need to get a selection of nuts and bolts as spares as my 1984 Ford 2722 engine is all imperial (or American anyway!). I have spanners and sockets etc, but I am not sure whether I have UNC or UNF threads? Does anyone know or know how I measure a bolt to see??

Thanks


Puggy

I am puzzled as to why you would need spare nuts and bolts for the engine?
S

 

[VicS]

I am sure you mean machine screw (ie a bolt threaded right up to the head) not a wood screw

The OP might not realise this

A hex headed bolt which is threaded all the way is known as a SET screw ( in the UK at least)

Machine screws are similarly fully threaded but have pan, cheese, dome or countersunk heads etc., which may be slotted, Philips, Pozidrive, Torx etc


.

 

[Puggy]

I am puzzled as to why you would need spare nuts and bolts for the engine?
S

It is a marinised industrial (ie tractor!) engine and so all the cooling system, charging system etc are all external and aftermarket. I have overhauled and replaced much of it, and I didn't have any new fastenings to replace tired ones or to attach the new elements like the high output alternator. Previous engines have been metric and I have always taken it for granted that I have a spare bolt if need be..

 

[Puggy]

A hex headed bolt which is threaded all the way is known as a SET screw ( in the UK at least)

Machine screws are similarly fully threaded but have pan, cheese, dome or countersunk heads etc., which may be slotted, Philips, Pozidrive, Torx etc


.

Thanks VicS and all for helpful advice.

 

[Mermaid-Jon]

It is a marinised industrial (ie tractor!) engine and so all the cooling system, charging system etc are all external and aftermarket. I have overhauled and replaced much of it, and I didn't have any new fastenings to replace tired ones or to attach the new elements like the high output alternator. Previous engines have been metric and I have always taken it for granted that I have a spare bolt if need be..

Puggy, The Ford 2722E is actually based on the Ford Cargo truck engine and as far as I know was never used in a tractor of any description. It should not be confused with the Ford tractor engine which is an entirely different family of engines and has absolutely no similarity or share any common parts. The 2722E was produced between 1981 and 1992. If you need a service or parts manual then these are available as a free download from our website if it will help.

All the best
Jon