UNITED STATES STANDARD SIZES OF BOLTS.

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| |DISTANCE| | |

| | ACROSS |DISTANCE| |

| | FLATS, | ACROSS | THICK- |

| DIAM-| SQUARE |CORNERS,| NESS |

| ETER.|AND HEX.| HEX. |OF HEAD.|

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| ¹⁄₄″| ¹⁄₂″ | ⁹⁄₁₆″ | ¹⁄₄″ |

| ³⁄₈ | ¹¹⁄₁₆ | ²⁵⁄₃₂ | ¹¹⁄₃₂ |

| ¹⁄₂ | ⁷⁄₈ | 1 | ⁷⁄₁₆ |

| ⁵⁄₈ | 1¹⁄₁₆ | 1⁷⁄₃₂ | ¹⁷⁄₃₂ |

| ³⁄₄ | 1¹⁄₄ | 1⁷⁄₁₆ | ⁵⁄₈ |

| ⁷⁄₈ | 1⁷⁄₁₆ | 1²¹⁄₃₂ | ²¹⁄₃₂ |

| 1 | 1⁵⁄₈ | 1⁷⁄₈ | ¹³⁄₁₆ |

| 1¹⁄₈ | 1¹³⁄₁₆ | 2³⁄₃₂ | ²⁹⁄₃₂ |

| 1¹⁄₄ | 2 | 2⁵⁄₁₆ | 1 |

| 1³⁄₈ | 2³⁄₁₆ | 2¹⁄₂ | 1³⁄₃₂ |

| 1¹⁄₂ | 2³⁄₈ | 2³⁄₄ | 1³⁄₁₆ |

| 1⁵⁄₈ | 2⁹⁄₁₆ | 2¹⁵⁄₁₆ | 1⁹⁄₃₂ |

| 1³⁄₄ | 2³⁄₄ | 3³⁄₁₆ | 1³⁄₈ |

| 1⁷⁄₈ | 2¹⁵⁄₁₆ | 3¹³⁄₃₂ | 1¹⁵⁄₃₂ |

| 2 | 3¹⁄₈ | 3⁵⁄₈ | 1⁹⁄₁₆ |

| 2¹⁄₄ | 3¹⁄₂ | 4¹⁄₁₆ | 1³⁄₄ |

| 2¹⁄₂ | 3⁷⁄₈ | 4¹⁄₂ | 1¹⁵⁄₁₆ |

| 2³⁄₄ | 4¹⁄₄ | 4⁷⁄₈ | 2¹⁄₈ |

| 3 | 4⁵⁄₈ | 5¹¹⁄₃₂ | 2⁵⁄₁₆ |

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Self-Help Mechanical Drawing: An Educational Treatise · 第 137 / 140 题