Screw core plugs

[Charles P]

Are the large sized screw in core plugs found on the early blocks available anywhere?
I could make some but if they're a standard size it would save some hard work.

Thanks

Charles

[Ian Williams]

I was recently told by Steve Hainsworth they are a BSP thread that is still available from plumbers merchants here in NZ.

[Charles P]

Thanks Ian

In which case I'll take one out of a less desirable, tired block and see if it's correct before I remove the core plugs on my best "next in line" block!

Charles

[Alan]

How do you get them out? I've never been brave enough to try.

[Steve Jones]

How do you get them out? I've never been brave  enough to try.

I've a well knackered block with screw in core plugs. I'll have a go at getting one out this afternoon

Steve

[Alan]

I would but I have to go to the pub in the Chummy in a minute. It's a hard life.

[Robert Foreman]

How do you get them out? I've never been brave  enough to try.

I've a well knackered block with screw in core plugs. I'll have a go at getting one out this afternoon

Steve

I have removed them only by milling them out of a scrap block. From memory they are 1 1/4" x16 t.p.i

[Charles P]

Thanks Steve.
Happy to keep the retired busy by setting these challenges

c

[Steve Jones]

How do you get them out? I've never been brave  enough to try.

I've a well knackered block with screw in core plugs. I'll have a go at getting one out this afternoon

Steve

I have removed them only by milling them out of a scrap block. From memory they are 1 1/4" x16 t.p.i

Well I don't have a mill and I should, probably, not offend the engineering principles of both Alan and Robert that I respect greatly but I've just got one out by 'other means'. I've got it here on my desk and I agree with 1 1/4" x 16tpi which doesn't seem to match anything listed by Mr. Zeus. My more crude method didn't damage the boss in the block so it can be done

Steve

Edited to Add: See Page 114 of 'The Companion'. Size confirmed and, in 1956 at least, these were available in the electrical trade as '1 1/4" Male Bushes'.

[Charles P]

Thanks Steve

Isn't that the fabled "Admiralty" thread - a hangover from fixed tpi threads that Austin used in the great war. 1 1/4" x16 appears on the rear hubs as well.
I seem to remember my old M Type Drummond lathe used Admiralty and Admiralty Fine (20 tpi) threads

Charles