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techtalk:ref:tools806 [2020/04/28 23:03] hippysmack [Grade Marks and Material Properties for Bolts and Screws] |
techtalk:ref:tools806 [2021/01/29 01:07] (current) hippysmack |
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| [[:techtalk:menu|{{ :techtalk:gototechnicalmenu.jpg|}}]] | [[:techtalk:menu|{{ :techtalk:gototechnicalmenu.jpg|}}]] | ||
| - | ====== REF: HD List of Hardware P/N & Descriptions ====== | ||
| - | \\ | ||
| ====== Strengths Of Various Fasteners ====== | ====== Strengths Of Various Fasteners ====== | ||
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| ====== Grade Marks and Material Properties for Bolts and Screws ====== | ====== Grade Marks and Material Properties for Bolts and Screws ====== | ||
| - | Bolts, screws and other fasteners are marked on the head with a symbol that identifies the grade of the fastener.\\ | + | Bolts, screws and other fasteners are marked on the head with a symbol that identifies the grade of the fastener. ((Machinery's Handbook 27th Edition dated 2004 pg 1508)) \\ |
| The grade specification establishes the minimum mechanical properties that the fastener must meet. \\ | The grade specification establishes the minimum mechanical properties that the fastener must meet. \\ | ||
| Additionally, industrial fasteners must be stamped with a registered head mark that identifies the manufacturer. \\ | Additionally, industrial fasteners must be stamped with a registered head mark that identifies the manufacturer. \\ | ||
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| {{:techtalk:ref:svcproc:bolt_head_grade_markings.jpg?direct&300|}} ((drawing by Hippysmack)) \\ | {{:techtalk:ref:svcproc:bolt_head_grade_markings.jpg?direct&300|}} ((drawing by Hippysmack)) \\ | ||
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| + | ====== Mechanical Properties and Grade Markings of Nuts ====== | ||
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| + | Three grades of hex and square nuts designated Grades 2, 5, and 8 are specified by the SAE 1995 standard covering nuts in the 1/4" to 1-1/2" diameter range. ((Machinery's Handbook 27th Edition dated 2004 pg 1509)) \\ | ||
| + | Grades 2, 5, and 8 nuts roughly correspond to the SAE specified bolts of the same grade. \\ | ||
| + | Additional specifications are given for miscellaneous nuts such as hex jam nuts, hex slotted nuts, heavy hex nuts, etc. \\ | ||
| + | Generally speaking; use nuts of a grade equal to or greater than the grade of the bolt being used. \\ | ||
| + | * Grade 2 Nuts: | ||
| + | * Grade 2 nuts are not required to be marked. | ||
| + | * Grade 5 Nuts (1/4" to 1-1/2" range): | ||
| + | * A dot on the face of the nut and a radial or circumferential mark at 120° counterclockwise from the dot. | ||
| + | * Or a dot at one corner of the nut and a radial line at 120° clockwise from the nut. | ||
| + | * Or one notch at each of the six corners of the nut. | ||
| + | * Grade 8 Nuts (1/4" to 1-1/2" range): | ||
| + | * A dot on the face of the nut with a radial or circumferential mark at 60° counterclockwise from the dot. | ||
| + | * Or a dot at one corner of the nut and a radial line at 60° clockwise from the nut. | ||
| + | * Or two notches at each of the six corners of the nut. | ||
| + | |||
| ====== Detecting Counterfeit Fasteners ====== | ====== Detecting Counterfeit Fasteners ====== | ||
| - | Fasteners with markings identifying them as a specific grade or property class are counterfeit if they don't meet standards established for that class. \\ | + | Fasteners with markings identifying them as a specific grade or property class are counterfeit if they don't meet standards established for that class. ((Machinery's Handbook 27th Edition dated 2004 pg 1509)) \\ |
| Counterfeit fasteners may break unexpectedly at smaller loads than expected. \\ | Counterfeit fasteners may break unexpectedly at smaller loads than expected. \\ | ||
| Generally, these fasteners are made from the wrong material or they are not properly strengthened during manufacturing. \\ | Generally, these fasteners are made from the wrong material or they are not properly strengthened during manufacturing. \\ | ||
