Appendix B Common Hardware Application Guidelines
Use the information below and on the following pages to identify proper fastening techniques when no specific reference for reassembly is made.
Bolt/Screw Length: When bolt/screw length is not given, use Figure 1 as a guide. As a general rule, a minimum length of one thread beyond the nut and a maximum length of 1/2 the bolt/screw diameter beyond the nut is the preferred method.
Washers and Nuts: Use split lock washers as a bolt locking device where specified. Use SAE flat washers with whiz nuts, spiralock nuts, or standard nuts and preloading (torque) of the bolt in all other applications.
See Appendix C, General Torque Specifications, and other torque specifications in the service literature.
Preferred Nut/Bolt Clearance
12
Unacceptable Nut/Bolt Clearance
3
1.1/2 of bolt diameter
2.Min. 1 full thread beyond top of nut
3.Below top of nut
Figure 1 Acceptable Bolt Lengths
Steps for common hardware application:
1.Determine entry hole type: round or slotted.
2.Determine exit hole type: fixed female thread (weld nut), round, or slotted.
For round and slotted exit holes, determine if hardware is greater than 1/2 inch in diameter, or 1/2 inch in diameter or less. Hardware that is greater than 1/2 inch in diameter takes a standard nut and SAE washer. Hardware 1/2 inch or less in diameter can take a properly torqued whiz nut or spiralock nut. See Figure 2.
3.Follow these SAE washer rules after determining exit hole type:
a.Always use a washer between hardware and a slot.
b.Always use a washer under a nut (see 2 above for exception).
c.Use a washer under a bolt when the female thread is fixed (weld nut).
4.Refer to Figure 2, which depicts the preceding hardware configuration possibilities.
2
1
3
5
6
4
1.Cap screw
2.Entry hole types
3.Standard nut and SAE washer
4.Whiz nut or spiralock: up to 1/2 in. dia. hardware
5.Weld nuts: above 1/2 in. dia. hardware
6.Exit hole types
Figure 2 Acceptable Hardware Combinations
Appendix 57 |