Thread: Sourcing or converting a backplate for 1.5" 8TPI 55deg

Hi Phil,
Thanks
I finally found the right table. Machinery's Handbook 28 page1721

Yes I have it back to front.


Stuart

p.s. talking about the war, wasn't it WWII when they made 1 inch =25.4mm? Or do I have that wrong as well? lol

i had same trouble trying to fit a chuck from a hercus to a tom senior indexing head 1 1/2x 8 tpi it wont fit like it is
hercus is 1 1/2 x 8 un
tom senior is 1 1/2 x 8 bsf
got a thread tap 1 1/2 x 8 bsf and now it fits both
probably not how the thread police do it tho
john

HI,
This Place might have what You want shars.com - Threaded Back Plates

Originally Posted by morrisman

Which war ? WW1 I presume MIKE

Sorry mike
WW2

Phil

Originally Posted by Stustoys

p.s. talking about the war, wasn't it WWII when they made 1 inch =25.4mm? Or do I have that wrong as well? lol

Hi Stuart
I am not sure on this one but if my memory serves me correct it was accepted as 25.4 mm not long after I was born
That was in 1958
I just remember its about as old as me which at the moment is real old lol

Phil

Hi Phil,
I want looking, you're correct again. 1959 is seems.
Inch - Wikipedia, the free encyclopedia

Stuart

IOf you can make your own a local version is available (cast iron backplate) from ebay LATHE BACKING PLATE 165mm O.D CAST IRON ROUGH MACHINED | eBay
is melbourne based and may have finished ones
Pete

Originally Posted by steran50

HI,
This Place might have what You want shars.com - Threaded Back Plates

Stewart,

Any threaded backplates from Shars will almost certainly have 60 degree threads - that's what their domestic market commonly uses.

Frank

HI franco,
Yes You're quite right My mistake .

Unixbigot
Did you sort out your backplate thread yet .?

A lot of confusion in the posts above .
But tanii51 got it right

If the nose of your lathe is 1.5" x 8 TPI and you think that it is 55 degree profile then the thread that you need is 1.5" British Standard Fine BSF, no question !!
Do not confuse with British Standard Whitworth, BSW. Whilst it, BSW, is also 55 degree thread form, a 1.5 diam thread would be 6 TPI
I have a UK manufactured lathe called Denford Viceroy that uses that size backplate as does a Boxford lathe, also made in UK . You can see some examples of mine and some Mars lathes and hundreds of other lathes and milling machines at WWW.lathes.co.uk . Incidentally, the owner of that site would like to hear from anybody with a Mars lathe . It seems they are very rare . I have a couple of brand new unused backplates with thread and registers factory cut . If you really are stuck, I would sell you one for UK £10.00 but I think that the postage to Brisbane would work out very expensive .
See if you can find a 1.5 x 8 TPI BSF tap and run it through your backplate . There is also a UK Ebay guy selling one .
11/2" BSF no3 threading tap | eBay

It would probably be cheaper to buy and have sent than my heavy backplate .
Remember, the thread just holds it on, the registers should do the locating and lineup . .
Rgds
Davycrocket

Anyone else unable to see the last post in this thread (2.2.12, 4.55am, Davycrocket 2nd)? I've had this happen before too.

Now you see it now you don't !!!

Davycrocket

All is revealed. And a most helpful post too. Welcome aboard Davycrocket 2nd. (Was that your Dad I used to watch on TV as a kid?)

Bryan, have you ever thought of doing standup.