what does this mean on a drawing

[DismalduncParticipant @dismaldunc]

hi chaps just perusing the drawings that came with my german “bengs” stirling engine, I think the drawings have been translated into english as the wording is a bit dodgy, however there are lots of references to drilled holes ,borings etc that are written as 6H7. 4H7 10H7 and one PCD which is listed as LK17.

is H a wierd german decimal point?

 

thanks in advance

 

Duncan

[DismalduncParticipant @dismaldunc]

[The Merry MillerParticipant @themerrymiller]

 

Hi Duncan,

 

6H7 etc are all references to classes of limits and fits extracted from the latest ISO documentation.

You need to consult a Machinery’s handbook or suchlike to get the fuller picture.

Haven’t a clue what the LK17 means!.

 

Len. P.

 

 

[steve 1Participant @steve1]

hi there

the H7 applied to the holes are the codes for the type of fit required,These can be anything from a loose clearance fit to a very tight interference fit.The tolerances used are all in ISO-286.look at this link for a start.

 

http://www.roymech.co.uk/Useful_Tables/ISO_Tolerances/ISO_286_2s.html

 

no idea as to the LK17.

 

good luck steve c

[Peter EParticipant @petere]

Hi Duncan,

 

You say that the drawings are german and then translated. Using Google translate I find that PCD in english = Lochkreis (hole circle) in german. and then the number tells the diameter in mm.

 

The “H” in the hole specs tells what fit it is. H7 is a close slide fit if I remember correctly and the number before is the hole size in diameter. So 10 H7 says a 10 mm hole with a close slide fit.

 

Hope this helps.

 

BR

 

/Peter

 

Edit: Just noticed that there were more than me answering at the same time   As was recommended above, look in the ISO specs for the correct fit for H7.

Edited By Peter E on 15/11/2011 15:41:44

[GoCreateParticipant @gocreate]

Here is a useful tolerance chart
hole tolerance

[S.D.L.Participant @s-d-l]

Posted by Duncan Jennings on 15/11/2011 15:14:49:

hi chaps just perusing the drawings that came with my german “bengs” stirling engine, I think the drawings have been translated into english as the wording is a bit dodgy, however there are lots of references to drilled holes ,borings etc that are written as 6H7. 4H7 10H7 and one PCD which is listed as LK17.

is H a wierd german decimal point?

 

thanks in advance

 

Duncan

6H7 means 6mm tole tolerance H7

 

This can be looked up here

 

http://www.tribology-abc.com/calculators/iso_holes.htm

 

Column down Left hand side is tol class H6 H7 etc actual tolerance changes with size so look across top and find range in 3-6 so tolerance is -0 + 8 um ie 6.000 to 6.008

 

ON the LK ref is the PCR or PCD 17mm?

 

Steve Larner

 

[DismalduncParticipant @dismaldunc]

by gum that wuza rapid response thank chaps saved the day again!

[StyxParticipant @styx]

Hi Duncan,

I have just bought Kalle. Is this the same engine as you have? I have emailed the company asking for a set of English instructions but as yet have had no response.

Good luck with the build.

Steve….

[DismalduncParticipant @dismaldunc]

hi steve, the engine i bought was the “Laura” the kit came with english (sort of) instructions. When I ordered it there was a drop down list of languages. I think the translation is software derived as although the words are correct the sense is not that clear. having said that there is only one sheet of words and the kit seems to come with enough bits to allow for my inevitable cock ups.

Let me know how you get on! Dunc

[mgjParticipant @mgj]

Also you will find that reamers and the like are classed as Hx as well. The standard I think is an H5 IRRC, but you can get what you wan’t – if you want to pay for it.

[Jeff DaymanParticipant @jeffdayman43397]

The LK in LK17 probably stands for “lochkreisdurchmesser” which means “hole circle diameter” in German. The 17 is likely 17 mm. I have seen this LK designation on various German drawings in industry.

 

JD

[S.D.L.Participant @s-d-l]

Posted by mgj on 16/11/2011 10:20:54:

Also you will find that reamers and the like are classed as Hx as well. The standard I think is an H5 IRRC, but you can get what you wan’t – if you want to pay for it.

 

I believe that Dormer and presto are normally H7 inline with the Din standard.

 

This page also tells you the tolerance on the reamer.

 

http://www.presto-tools.co.uk/files/reamers-pages.pdf

 

and here-for Dormer

http://www.dormertools.com/sandvik/2531/internet/s003592.nsf/Alldocs/Product*2DMachiningSolutions*2DPDF*2ATH*2DPDFen/$file/3Reaming.pdf

 

Steve Larner

[Author]

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