marlco thread parallels

[Michael DevlinParticipant @michaeldevlin84947]

I have a set of Whitworth thread parallels, they look easier to use than wires but what is the correct way of use?

Mike

[Michael DevlinParticipant @michaeldevlin84947]

[chris stephensParticipant @chrisstephens63393]

Hi Gray,

I am glad you posted this as I bought a set of metric ones on Saturday for a tenner and now I know I know how to use them. No plastic clips but I am sure that is not an insurmountable problem.

chriStephens

[chris stephensParticipant @chrisstephens63393]

What ho Gray,

That's the beauty of Google, your post came up about the use of the parallels. It also gives the current makers price list, including the plastic bits. I don't however expect them to sell many parallels at their present mega rip off price.

There is a better way than three wire, single wire. Wrap a bit of copper wire, of the right diameter, around the thread pull tight and then measure. Copper wire comes in the same gauges as the three wire wire.

Just so you know not to look, my visage will most likely appear in the next Journal, they gave me an award.

ATB

chriStephens

[chris stephensParticipant @chrisstephens63393]

Sir, You flatter me, but I should warn you flattery will get you nowhere, I'm too used to it

chriStephens

PS it wasn't just one (puffs out chest with pride, or is that embarrassment )

[NobbyParticipant @nobby]

Hi Guy's
Has anybody got or know where I can find the tables for the MARLCO Whitworth set of measuring parallels
Regards Nobby

[Michael GilliganParticipant @michaelgilligan61133]

Nobby,

Try this **LINK**

http://www.10pdm.com/pages/WDS/files/assets/common/downloads/page0852.pdf

MichaelG.

[chris stephensParticipant @chrisstephens63393]

Hi Nobby,

MichaelG's answer gives all that is needed to operate the parallels, but if you are looking for "effective diameter" figures Machinery Handbook, Zeus or mdmetric.com/thddata.htm (where it is called pitch diameter.) will give all you need to know.

If you have digital calipers or Mic, measure the two parallels, reset zero and then measure with the thread between them, the figure on the digital reading will be the pitch/effective diameter directly with no need for any maths.

Hope this helps

chriStephens

[NobbyParticipant @nobby]

Hi Chris & Michael
Thank you both for the info It helps a great deal .
Regards Nobby

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