Hi

Can I use a 3/8"-20 BSW bolt in 3/8"-20 UNC thread? I'm making an adapter
plate for my theodolite tripod so I can mount a camera or spotting scope.
The tripod screw is 5/8" UNC and I've managed to source the drill and taps
for this end of the plate. But at the other end, the tripod head has a 3/8"
UNC socket and I need a bolt to screw into it. Just one. There are only
about 5 turns in the socket.

The only UNC bolts I can find on Ebay are from USA and the postage is £27!
So can I cheat and use a BSW bolt?

Cheers

In article ,
Peter Taylor wrote:
Can I use a 3/8"-20 BSW bolt in 3/8"-20 UNC thread? I'm making an
adapter plate for my theodolite tripod so I can mount a camera or
spotting scope. The tripod screw is 5/8" UNC and I've managed to source
the drill and taps for this end of the plate. But at the other end,
the tripod head has a 3/8" UNC socket and I need a bolt to screw into
it. Just one. There are only about 5 turns in the socket.

The only UNC bolts I can find on Ebay are from USA and the postage is
£27! So can I cheat and use a BSW bolt?

http://www.namrick.co.uk/acatalog/Ho..._Screw_10.html

--
*Reality is the illusion that occurs due to the lack of alcohol *

Dave Plowman London SW
To e-mail, change noise into sound.

On 07/06/2014 22:41, Peter Taylor wrote:
Hi

Can I use a 3/8"-20 BSW bolt in 3/8"-20 UNC thread? I'm making an adapter
plate for my theodolite tripod so I can mount a camera or spotting scope.
The tripod screw is 5/8" UNC and I've managed to source the drill and taps
for this end of the plate. But at the other end, the tripod head has a 3/8"
UNC socket and I need a bolt to screw into it. Just one. There are only
about 5 turns in the socket.

The only UNC bolts I can find on Ebay are from USA and the postage is £27!
So can I cheat and use a BSW bolt?

Cheers



Technically they're not interchangeable because the thread angles are
slightly different - but to all intents and purposes they *are*,
especially for relatively light loads.
--
Cheers,
Roger
____________
Please reply to Newsgroup. Whilst email address is valid, it is seldom
checked.

"Dave Plowman (News)" wrote in message
...
In article ,
Peter Taylor wrote:
Can I use a 3/8"-20 BSW bolt in 3/8"-20 UNC thread? I'm making an
adapter plate for my theodolite tripod so I can mount a camera or
spotting scope. The tripod screw is 5/8" UNC and I've managed to source
the drill and taps for this end of the plate. But at the other end,
the tripod head has a 3/8" UNC socket and I need a bolt to screw into
it. Just one. There are only about 5 turns in the socket.

The only UNC bolts I can find on Ebay are from USA and the postage is
£27! So can I cheat and use a BSW bolt?

http://www.namrick.co.uk/acatalog/Ho..._Screw_10.html

Thanks Dave, I forgot to mention it needs to be brass.

"Roger Mills" wrote in message
...

Technically they're not interchangeable because the thread angles are
slightly different - but to all intents and purposes they *are*,
especially for relatively light loads.
--
Cheers,
Roger

Thanks Roger, that's what I'll do then. The bolt will only be finger tight.

I wondered if the threads would bind or be too loose. I didn't have any way
of testing it, so thanks for the info.

Peter

On 08/06/2014 12:10, Peter Taylor wrote:
"Dave Plowman (News)" wrote in message
...
In article ,
Peter Taylor wrote:
Can I use a 3/8"-20 BSW bolt in 3/8"-20 UNC thread? I'm making an
adapter plate for my theodolite tripod so I can mount a camera or
spotting scope. The tripod screw is 5/8" UNC and I've managed to source
the drill and taps for this end of the plate. But at the other end,
the tripod head has a 3/8" UNC socket and I need a bolt to screw into
it. Just one. There are only about 5 turns in the socket.

The only UNC bolts I can find on Ebay are from USA and the postage is
£27! So can I cheat and use a BSW bolt?

http://www.namrick.co.uk/acatalog/Ho..._Screw_10.html

Thanks Dave, I forgot to mention it needs to be brass.

You might find them in various local metalwork dealers that cater for
imported US cars.

Although brass might not be an option. If you say where you are then
someone might be able to point to a helpful shack or Alladin's cave.

--
Regards,
Martin Brown

"Martin Brown" wrote

You might find them in various local metalwork dealers that cater for
imported US cars.

That's a good thought! I have a friend who drives a pink Cadillac (I
think). I'll ask him.

If you say where you are then someone might be able to point to a helpful
shack or Alladin's cave.

I'm near HIgh Wycombe (Buckinghamshire).

On Sun, 08 Jun 2014 13:32:37 +0100, Peter Taylor wrote:

If you say where you are then someone might be able to point to a
helpful shack or Alladin's cave.

I'm near HIgh Wycombe (Buckinghamshire).

Orbital Fasteners in Rickmansworth or HMF in Amersham. I seem to remember
there's a fastener place in Chesham, too, near the Lido.

If none of that lot can help, and none know anybody that can, then you're
definitely going to be down to specialists on t'web.

On Sun, 8 Jun 2014 13:32:37 +0100, Peter Taylor wrote:

"Martin Brown" wrote

You might find them in various local metalwork dealers that cater for
imported US cars.

That's a good thought! I have a friend who drives a pink Cadillac (I
think). I'll ask him.

If you say where you are then someone might be able to point to a helpful
shack or Alladin's cave.

I'm near HIgh Wycombe (Buckinghamshire).

In that case you're near the cave and the pink Caddy would be enough to get
you in! ;-)
--
Peter.
The gods will stay away
whilst religions hold sway

In article ,
Martin Brown wrote:
The only UNC bolts I can find on Ebay are from USA and the postage is
£27! So can I cheat and use a BSW bolt?

http://www.namrick.co.uk/acatalog/Ho..._Screw_10.html

Thanks Dave, I forgot to mention it needs to be brass.

You might find them in various local metalwork dealers that cater for
imported US cars.


Trying to think what you'd use such a (relatively) large ordinary brass
bolt for on any car. Special types for some electrics, possibly.

--
*If you remember the '60s, you weren't really there

Dave Plowman London SW
To e-mail, change noise into sound.

On Sun, 08 Jun 2014 18:46:35 +0100, Dave Plowman (News) wrote:

Trying to think what you'd use such a (relatively) large ordinary brass
bolt for on any car. Special types for some electrics, possibly.

Weren't exhaust down pipe to manifold bolts brass at some point?

--
Cheers
Dave.

On 08/06/2014 19:33, Dave Liquorice wrote:
On Sun, 08 Jun 2014 18:46:35 +0100, Dave Plowman (News) wrote:

Trying to think what you'd use such a (relatively) large ordinary brass
bolt for on any car. Special types for some electrics, possibly.

Weren't exhaust down pipe to manifold bolts brass at some point?


I think it may have been just the nuts which were brass - and they'd
probably have been 5/16 rather than 3.8
--
Cheers,
Roger
____________
Please reply to Newsgroup. Whilst email address is valid, it is seldom
checked.

On 08/06/2014 22:13, Roger Mills wrote:
On 08/06/2014 19:33, Dave Liquorice wrote:
On Sun, 08 Jun 2014 18:46:35 +0100, Dave Plowman (News) wrote:

Trying to think what you'd use such a (relatively) large ordinary brass
bolt for on any car. Special types for some electrics, possibly.

Weren't exhaust down pipe to manifold bolts brass at some point?


I think it may have been just the nuts which were brass - and they'd
probably have been 5/16 rather than 3.8

http://www.cameragrip.co.uk/acatalog...on_bushes.html

"dennis@home" wrote:

http://www.cameragrip.co.uk/acatalog...on_bushes.html

Thanks Dennis, that's a very useful resource I hadn't found before.

Here's a pic of the tripod:
http://www.euphonium.plus.com/images...ripod_head.jpg

The tripod has a flat top plate with a hole about 80mm diameter in the
centre, through which the brass fixing screw projects. The screw is free to
move around in the hole to enable the theodolite to be positioned accurately
over a point on the ground. This means I can't use the conversion bushes,
and the only way I can think of to keep the screwsolidly in a fixed position
is to use a brass bridge spanning across the hole, drilled and tapped
5/8" UNC for the screw, and this bit works fine. The problem is the bridge
needs to be min. 10mm thick, otherwise the end of the screw projects above
the surface, and that's too thick for any camera screws I've seen till now,
which is why I was intending to use a bolt.

The screw in your link with 15mm thread length might be long enough, but
it still leaves only 5mm thread above the bridge and I'm not sure that's
going to be really secure, but I'm going to order some to try.

Discussing it with a friend yesterday he suggested reducing the thickness of
the bridge locally for the screw using a spotface cutter, which means the
15mm screw will be OK. It would also let me use a circlip to retain the
screw.

Getting there slowly! Thanks very much for your link.

Peter

On Sun, 08 Jun 2014 23:39:04 +0100, dennis@home wrote:

http://www.cameragrip.co.uk/acatalog...___conversion_
bushes.html

Oh thanks for that. Prices might be a bit steep. Doesn't have what I
really want, 1/4" or 3/8" female in a sensible thickness plate no
larger than about 3/4" that would bolt to a small plastic box.

--
Cheers
Dave.

On 09/06/2014 08:38, Peter Taylor wrote:
"dennis@home" wrote:

http://www.cameragrip.co.uk/acatalog...on_bushes.html

Thanks Dennis, that's a very useful resource I hadn't found before.

Here's a pic of the tripod:
http://www.euphonium.plus.com/images...ripod_head.jpg

The tripod has a flat top plate with a hole about 80mm diameter in the
centre, through which the brass fixing screw projects. The screw is free to
move around in the hole to enable the theodolite to be positioned accurately
over a point on the ground. This means I can't use the conversion bushes,
and the only way I can think of to keep the screwsolidly in a fixed position
is to use a brass bridge spanning across the hole, drilled and tapped
5/8" UNC for the screw, and this bit works fine. The problem is the bridge
needs to be min. 10mm thick, otherwise the end of the screw projects above
the surface, and that's too thick for any camera screws I've seen till now,
which is why I was intending to use a bolt.

The screw in your link with 15mm thread length might be long enough, but
it still leaves only 5mm thread above the bridge and I'm not sure that's
going to be really secure, but I'm going to order some to try.

Discussing it with a friend yesterday he suggested reducing the thickness of
the bridge locally for the screw using a spotface cutter, which means the
15mm screw will be OK. It would also let me use a circlip to retain the
screw.

Getting there slowly! Thanks very much for your link.

This lot will do custom engineering for a price (as will Telescope House).

http://srb-photographic.co.uk/

They also have a lot of other useful and rare photographic goodies.

--
Regards,
Martin Brown

In article o.uk,
Dave Liquorice wrote:
On Sun, 08 Jun 2014 18:46:35 +0100, Dave Plowman (News) wrote:

Trying to think what you'd use such a (relatively) large ordinary brass
bolt for on any car. Special types for some electrics, possibly.

Weren't exhaust down pipe to manifold bolts brass at some point?

Usually steel studs with brass nuts.

--
Small asylum seeker wanted as mud flap, must be flexible and willing to travel

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
Peter Taylor wrote:
"Dave Plowman (News)" wrote in message
...
In article ,
Peter Taylor wrote:
Can I use a 3/8"-20 BSW bolt in 3/8"-20 UNC thread? I'm making an
adapter plate for my theodolite tripod so I can mount a camera or
spotting scope. The tripod screw is 5/8" UNC and I've managed to source
the drill and taps for this end of the plate. But at the other end,
the tripod head has a 3/8" UNC socket and I need a bolt to screw into
it. Just one. There are only about 5 turns in the socket.

The only UNC bolts I can find on Ebay are from USA and the postage is
£27! So can I cheat and use a BSW bolt?

http://www.namrick.co.uk/acatalog/Ho..._Screw_10.html

Thanks Dave, I forgot to mention it needs to be brass.

Does it need to be brass? Is it for an underwater camera? ;-)

A decent engineering workshop should be able to turn one up for you out of
brass. But it would cost.

--
*Experience is something you don't get until just after you need it *

Dave Plowman London SW
To e-mail, change noise into sound.

On Monday, 9 June 2014 08:38:40 UTC+1, Peter Taylor wrote:
"dennis@home" wrote:



http://www.cameragrip.co.uk/acatalog...on_bushes.html



Thanks Dennis, that's a very useful resource I hadn't found before.



Here's a pic of the tripod:

http://www.euphonium.plus.com/images...ripod_head.jpg



The tripod has a flat top plate with a hole about 80mm diameter in the

centre, through which the brass fixing screw projects. The screw is free to

move around in the hole to enable the theodolite to be positioned accurately

over a point on the ground. This means I can't use the conversion bushes,

and the only way I can think of to keep the screwsolidly in a fixed position

is to use a brass bridge spanning across the hole, drilled and tapped

5/8" UNC for the screw, and this bit works fine. The problem is the bridge

needs to be min. 10mm thick, otherwise the end of the screw projects above

the surface, and that's too thick for any camera screws I've seen till now,

which is why I was intending to use a bolt.



The screw in your link with 15mm thread length might be long enough, but

it still leaves only 5mm thread above the bridge and I'm not sure that's

going to be really secure, but I'm going to order some to try.



Discussing it with a friend yesterday he suggested reducing the thickness of

the bridge locally for the screw using a spotface cutter, which means the

15mm screw will be OK. It would also let me use a circlip to retain the

screw.



Getting there slowly! Thanks very much for your link.



Peter



Peter, I have some 3" x 3/8" BSW Brass bolts, nuts and washers that you are welcome to. Also, I have a matching second-cut tap that I will lend you if you need it.

Please answer through the group, as I am having problems with e-mail.
HTH!

Please answer through the group, as I am having problems with e-mail.

HTH!

My e-mail problem is cured; please e-mail if I can help!

Thanks very much indeed. Home and dry!

Peter

"Mr Fuxit" wrote

Please answer through the group, as I am having problems with e-mail.

HTH!

My e-mail problem is cured; please e-mail if I can help!

"Mr Fuxit" wrote:

Peter, I have some 3" x 3/8" BSW Brass bolts, nuts and washers that you
are welcome to. Also, I have a matching second-cut tap that I will lend
you if you need it.

Through the letterbox this morning came a little package of two brass bolts,
complete with nuts and washers, and a 3/8" BSW tap.

That's real kindness, totally unexpected and much appreciated. Thank you
very much indeed.

Peter