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In this blueprint, there's the line with a cross with diameter of .115 at the far right side. enter image description here

What does this line means?
Does it means that the section with length .13 has an inclination?

Also, can I assume that the 3 last sections on the right (rounded, then straight then angled) all have the same length?

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  • $\begingroup$ If it is what I think you are referring to (which is on several of the dimensions in the image), I believe those are tolerance measurements. $\endgroup$
    – agarza
    Mar 26, 2023 at 13:38
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    $\begingroup$ Also, why the metallurgy tag? $\endgroup$
    – agarza
    Mar 26, 2023 at 13:38
  • $\begingroup$ Only one part has an angle specified. $\endgroup$
    – Solar Mike
    Mar 26, 2023 at 14:06
  • $\begingroup$ @agarza, but the diameter with .107 already has tolerances. Could the value with the cross symbol (.115) be the diameter of the hole the part will be inserted in? $\endgroup$ Mar 26, 2023 at 14:09
  • $\begingroup$ Maybe if you were to indicate on the image itself what "cross" symbol you are referring to would help in answering your question. $\endgroup$
    – agarza
    Mar 26, 2023 at 14:48

1 Answer 1

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The symbol or variable for diameter, ⌀, is sometimes used in technical drawings or specifications as a prefix or suffix for a number (e.g. "⌀ 55 mm"), indicating that it represents diameter. For example, photographic filter thread sizes are often denoted in this way.

See https://en.wikipedia.org/wiki/Diameter.

The diameter symbol (⌀) (Unicode character U+2300) is similar to the lowercase letter ø, and in some typefaces it even uses the same glyph, although in many others the glyphs are subtly distinguishable (normally, the diameter symbol uses an exact circle and the letter o is somewhat stylized). The diameter symbol is used extensively in engineering drawings, and it is also seen in situations where abbreviating "diameter" is useful, such as on camera lenses. For example, a lens with a diameter of 82 millimeters would be engraved with " ⌀ 82 mm ".

From Wikipedia Talk.


Q1. What does this line means?
A1. Diameter symbol.

enter image description here

Figure 1. The ⌀ 0.115 indicates the centres of the radius.

Q2. Does it means that the section with length .13 has an inclination?
A2. No, it's showing the centres of the radius cut. Because the widest section of the pin has diameter of 0.107 we know that the curve doesn't meet the pin outer diameter at a right angle but at some angle > 90°.

Q3. Also, can I assume that the 3 last sections on the right (rounded, then straight then angled) all have the same length?
A3. No. The machinist would probably -

  • Cut the circular groove.
  • Cut the flat top on the right-hand end.
  • Profile it to 60°.
  • Turn the cylindrical section down to 0.0645.

The length of the flat section would just be whatever it turns out to be. If it's not dimensioned then it isn't important for the function of the pin.

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