super 7 cross top screw

[Anders BParticipant @andersb45152]

[Anders BParticipant @andersb45152]

Hi,

What is the pitch on a imperial screw and on the metric screw?

My lathe has 2mm pitch, but has an 100 division scale, which do not seem right..

Br

Anders

[HopperParticipant @hopper]

Imperial screw would be 10tpi or a pitch of .100", so each gradution on a 100 division dial is .001".

If you have a 2mm screw, each division on a 100 division dial will be 2/100 of a millimeter. So the five division mark will be .1 of a millimeter and the 10 division mark will be .2 of a mm. A 1mm cut would be at the 50th graduation.

Myford might be able to supply a dial with more metric-friendly markings on it. I'm not sure, being an old Imperialist!

Edited By Hopper on 24/04/2017 07:24:18

[Jon GibbsParticipant @jongibbs59756]

It's a pretty pragmatic approach though because at the end of the day, these two dials have very similar precision.

1 division on the metric dial is 0.02mm = 0.00078" and 1 division on the imperial dial is 0.001" = 0.0254mm.

Jon

[Anders BParticipant @andersb45152]

Ok thanks, but is that 100 division dial a metric dial ?

Edited By Anders B on 24/04/2017 07:38:00

[Nick HulmeParticipant @nickhulme30114]

Posted by Anders B on 24/04/2017 07:35:41:

Ok thanks, but is that 100 division dial a metric dial ?

Edited By Anders B on 24/04/2017 07:38:00

With a metric screw, yes

[Brian OldfordParticipant @brianoldford70365]

Anders B. It seems you may have a bit of a hybrid machine there.

The metric dial has 40 divisions thus http://www.ebay.co.uk/itm/METRIC-TOP-SLIDE-MICROMETER-DIAL-FOR-MYFORD-SUPER-7-Direct-From-Myford-/120832514071?hash=item1c222dd817:g:eNUAAMXQrhdTPqti

The imperial dial has 50 thus http://www.ebay.co.uk/itm/IMPERIAL-TOP-SLIDE-MICROMETER-DIAL-FOR-MYFORD-SUPER-7-Direct-From-Myford-/190905932619?hash=item2c72e15b4b:g:PCoAAMXQ74JTRPUj

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