Conversion Chart

[John HaineParticipant @johnhaine32865]

Make it a PDF

Put it on this site

Update it every so often as people suggest additional data

Print it in ME/MEW once a year.

This is 2013 folks.

[Gary WoodingParticipant @garywooding25363]

Posted by mechman48 on 06/06/2013 12:24:34:

Much as I support & welcome Daves idea for inclusion of charts; look in Roebucks 'ZEUS' pocket book (usual disclaimer).. available on flea bay etc, it has everything you would need .. tapping sizes, drill coordinates for jig boring, trigonometry, tapers, BS 4500.A ISO hole & shaft fits, etc,etc. The latest version I have.. metric revision, now includes – symbols & abreviations used on Engineering Dwgs, Misc' function words from USA-EIA standard, G code addresses for NC, letter addresses used in NC..

Cheers

George

Interestingly, I've just checked my rather old (1976) version of ZEUS, and calculated that its recommended tapping drill sizes are based on an approx 80% thread engagement.

Make of it what you will.

Gary

[Matts BitsNBobsParticipant @mattsbitsnbobs]

I went on google images, loads of conversion chart on there, pinted them off, laminated and hung on a nail in my workshop, like these

**LINK**

[JasonBModerator @jasonb]

DC, I would say 80% is a good idea for boiler fittings as there is a risk of the crests being burn/scorched away during soldering so having the larger engagement will "ensure screw threads are of adequate depth to maintain sufficient strength" as required by the regs.

J

[Sub MandrelParticipant @submandrel]

Having got used to metric taps which have different top diameters for each (taper, second, plug) tap, I now use a much bigger %engagement (80-90%) for metric threads. For other threads (where all my taps have the same top diameter) I generally use one number drill smaller than Tubal Caine recommends.

Neil

[David Clark 13Participant @davidclark13]

Hi There

I remember Zeus as 80% and thought it would be a good idea especially for boiler fittings.

The days of assuming a model engineer needs a large hole so he does not break a tap are long gone.

regards David

[Nicholas FarrParticipant @nicholasfarr14254]

Hi, I have use the Zeus tables since 1972 when I first bought one of their booklets and have never had any trouble tapping holes to those sizes.

I have an old Intel booklet also and the tapping holes are almost identical to those that have been printed in the recent MEW. Where they differ on the ME threads, Intel states slightly smaller holes and on the BA ones, only 0,2,3,9,10 and 13 are very slightly larger, while 14 is stated as 1/32" all the rest are exactly the same.

Regards Nick.

[David HaynesParticipant @davidhaynes53962]

What issue of MEW are these charts published in?

Dave

[Nicholas FarrParticipant @nicholasfarr14254]

Hi Dave, the charts are in issue 203.

In my previous post, Intel is spelt wrong, it should read Intal.

intel is to do with computers etc.

Regards Nick.

Edited By Nicholas Farr on 08/06/2013 11:55:54

[David HaynesParticipant @davidhaynes53962]

Thanks for that Nick. I am a subscriber to ME and I know David Clark mentioned about these sheets being available as PDF downloads. As I would like to get copies of the sheets, I wondered if this download applies to ME subscribers, or do I need to get MES 203?

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