JS tolerance questions 1

[Twullf]

The company I work for recently asked us to use machining tolerances for the hole and shafts that we have been working on. I am unfamiliar with these, and though I have found several charts on line, I would like one clarification.

Capital JS vs lowercase js. I believe that the capitalized tolerance, JS, H, E, F, etc, are used specifically used for holes, while the lower case versions are used for shafts.

Please let me know if this is correct.

Thank you in advance.

 

[KENAT]

Twullf, there are plenty of excerpts of the limit and fit tables online or in your machineries handbook etc.

https://www.google.com/search?q=tab...la:en-US:official&client=firefox-a&channel=sb

Posting guidelines faq731-376

http://eng-tips.com/market.cfm?

(probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484​

 

[JNieman]

Engineers Black Book, Machinerys Handbook, and several easily googled pages have great reference tables. I like using the standard limits/fits tables - it's a very elegant and simple/minimalist callout that communicates very specific information.

My Machinerys Handbook (27 ed) cites ANSI B4.1-1967(R1999)
MY Engineers Black Book 2005 edition cites ANSI B4.1-1967(R1979)/(R1984)

_________________________________________
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[juergenwt]

To answer you question: Capital letters are for HOLES or SLOTS in FITS!
Lower case are for SHAFTS ore OUTSIDE measures in FITS!
Get a hold of ISO/DIN 286 and study it. Google it. Learn how the system of fits and tolerances works. You will need it. MHB is a good source.

 

[CheckerHater]

ANSI/ASME B4.2 is pretty much the equivalent of ISO 286

Yes, capital letters refer to holes, lover case to shafts. hole can be anything measured from the inside (square, obround), shaft can be anything measured from outside.