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  1. #1
    Join Date
    Jan 2006
    Posts
    14
    Looked at the drawing the over all lenght is -+.02 on 1.70 in. long, i think, if i'm looking at the drawing right.

  2. #2
    Join Date
    Nov 2005
    Posts
    34

    Tolerance callouts are important

    Actually as a practical measure, it is indeterminate.

    There is no standard tolerance stated on the drawing for 4 decimal place dims. The most common tolerances are +-0.005 on dims with 3 decimal places and +-0.001 on dims with 4 decimal places. But the real standard is that the tolerances are to be stated on the drawing. To be honest it looks to me like whoever drew this drawing had the Dims set to 4 decimal places and didn't think beyond that.

    In that absence of other stated tolerances, cumulative dimensions have the cumulative tolerances of the sections making up the cumulative dimension.

    In the case of this drawing, the 0.740 dim could go from 0.720 to 0.760. The 0.960 dim could go from 0.940 to 0.980. Thus with no call out on the tolerance of the 1.7000 dim it could go from 1.640 (0.720 + 0.940) to 1.740 (0.760 + 0.980).

    If a quote were submitted with the drawing as is, the part could be from 1.640 to 1.740 and still be within tolerance.

    Point is, if you are going to submit a drawing for quotes, be sure EVERY tolerance is noted. Otherwise you may end up with parts that are "legal" within your drawing, but unusable to you. And if the machinist has produced the parts within anything close to accepted industry standards per the drawing, you may be liable to buy the parts.

    And stating all specs will get you the most accurate quote. As example, for this part if the 1.5000 dia can be stock dia and finish for 1.500 dia stock, the quote is going to be a lot less than if the machinist quotes based upon tuning down oversize stock to meet some un-needed tolerance and/or finish.

    Regards,
    Gary

    Quote Originally Posted by jr2840 View Post
    Looked at the drawing the over all lenght is -+.02 on 1.70 in. long, i think, if i'm looking at the drawing right.

  3. #3
    Join Date
    Feb 2006
    Posts
    1260
    Quote Originally Posted by netboss View Post
    Actually as a practical measure, it is indeterminate.

    There is no standard tolerance stated on the drawing for 4 decimal place dims. The most common tolerances are +-0.005 on dims with 3 decimal places and +-0.001 on dims with 4 decimal places. But the real standard is that the tolerances are to be stated on the drawing. To be honest it looks to me like whoever drew this drawing had the Dims set to 4 decimal places and didn't think beyond that.

    In that absence of other stated tolerances, cumulative dimensions have the cumulative tolerances of the sections making up the cumulative dimension.

    In the case of this drawing, the 0.740 dim could go from 0.720 to 0.760. The 0.960 dim could go from 0.940 to 0.980. Thus with no call out on the tolerance of the 1.7000 dim it could go from 1.640 (0.720 + 0.940) to 1.740 (0.760 + 0.980).

    If a quote were submitted with the drawing as is, the part could be from 1.640 to 1.740 and still be within tolerance.

    Point is, if you are going to submit a drawing for quotes, be sure EVERY tolerance is noted. Otherwise you may end up with parts that are "legal" within your drawing, but unusable to you. And if the machinist has produced the parts within anything close to accepted industry standards per the drawing, you may be liable to buy the parts.

    And stating all specs will get you the most accurate quote. As example, for this part if the 1.5000 dia can be stock dia and finish for 1.500 dia stock, the quote is going to be a lot less than if the machinist quotes based upon tuning down oversize stock to meet some un-needed tolerance and/or finish.

    Regards,
    Gary
    The 1.5 major od will be within tolerance if cold rolled stock material is used.

    The OAL length of 1.7" does have a large tolerance based on the +/-.020 allowed on the split. For clarification hold the OAL to .010

    The threads need be standard 75% bolt thread & can go to sholder or be relieved the length of 1 1/2 threads

    I have included .JPG image of a revised drawing.

    I apologise for the confusion. I'll try to be more precise in the future.
    Attached Thumbnails Attached Thumbnails MM-5035.jpg  
    If it works.....Don't fix it!

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