ASME B18.16.6 pdf download

ASME B18.16.6 pdf download.Nylon InsertLock nuts(Inch Series).
In cases where nuts are given a protective coating or are cleaned following delivery to the purchaser, the nut producer shall not be held responsible for failures of the nut to meet dimensional, mechanical, or performance ftluirements traceable to plating. coating. or cleaning practice.
11.1.4 Hydrogen Embrittlement. Nuts shall not be embrittled. When heat-treated nuts are electroplated or phosphate coated, appropriate plating or coating processes should he employed to avoid hydrogen mhrittlement. If necessary the product shall be suitably treated as soon as practicable after plating orcoating to preclude detrimental hydrogen embrittlement.
11.2 Mechanical Requirements
11.2.1 Proof Load. Nuts shall ssrithstand the proof load specified for the applicable grade and thread series in Table 2 or 3 when tested as specified in para. 12.1.
11.2.2 Hardness. Nuts shall have a hardness conforming to the limits specified for the applicable grade in Table 5 when tested as specified in para. 12.2.
11.3 Performance Requirements
11.3.1 Prevailing.Torque. The prevailing-torque developed by nuts during their first installation, or any subsequent installation or removal, shall not exceed the maximum first installation torque specified for the applicable grade in Table 2 or 3 when tested as specified in para. 12.3. In addition, minimum prevailing-torque generated by nuts during their first and fifth removals shall not be less than the respective removal torques specified for the applicable grade in Table 2 or 3.
12 TEST METHODS
12.1 Proof Load Test
The test sample nut shall be assembled on a test bolt (see para. 12.1.1) or on a hardened mandrel (see para. 12.1.2) with a minimum of three threads projecting through the nut. The proof load test may be performed prior to the prevailing-torque feature being added to the nut. For referee test purposes, the hardened mandrel shall be used and the prevailing-torque feature present. The maximum prevailing-torque occurring during the assembly of the nut on the test bolt or mandrel shall be recorded.
A load equal to the specified proof load for the nut, as given in Table 2 or 3, shall be applied in tension or compression through the test bolt or mandrel against the nut bearing surface in an axial direction For referee purposes, the load shall be applied in tension. The nut shall resist this load without thread stripping or rLlpture. The prevailing-torque necessary to remove the nut from the test bolt or mandrel shall not exceed the maximum torque occurring during assembly.
The bolt shall have an ultimate tensile strength not less than the specified proof load of the nut to be tested. The threads of heat-treated bolts shall have a metallurgical surface condition equal to Class B as specified in SAE J121. When test bolts less than in. in diameter are used, a new bolt shall be used for testing each nut. Bolts 34 in. and larger in diameter may be reused if upon inspection the thread condition is acceptable. In those instances in which a test mandrel is used, the mandrel may be reused if upon inspection the thread condition is acceptable.
12.3.4 Test Washer. Washers or multiple-hole test strips shall be plain finished and hardened to HRC 38 minimum. The washer’s outside diameter or strip width shall be larger than the maximum across corners or flange diameter, whichever is greater, of the nuts being tested. The inside diameter of the through hole shall conform to the inside hole diameters specified in either ASME B18.22.l, Type A or ASTM F 436. Washers and strips shall not be used for more than one test per hole side.
13 GRADE AND MANUFACTURING MARKING
Grade NIE2 nuts are required to be marked for source identification.
Grade NE5 nuts shall be marked with three equally spaced identical symbols on the top side of the nut.
Grade NES nuts shall be marked with six equally spaced identical symbols on the top side of the nut (see Table I for illustration).
Alternatively, when Grades NE5 and NE8 nuts are machined from bar stock, Grade NE5 nuts may be identified with one set of circumferential notches cut into the corners of the nut and Grade NES nuts with two sets of circumferential notches cut into the corners of the nut.