Fan Disk Lock WasherDIN : 6798 IS : 5556
This Indian Standard covers the requirement for serrated lock washers for threaded fasteners sizes in the range M 1.6 to 30.
The serrated lock washers for threaded fasteners shall be of the following three types:
- Type A- Externally toothed
- Type B- Internally toothed
- Type C- Countersunk externally toothed
The serrated lock washers shall confirm to precision grade of IS: 5369:1975.
The dimensions for type A and Type B serrated lock washers shall be given as in Table 1.
The dimensions for Type C serrated lock washers shall be given as in Table 2.
The serrated lock washers shall be made from suitable spring steel EN42J, 304, 316 and Copper.
For Spring Steel Washers- It shall be hardened and tempered to HV 430 to 530 tested in accordance with IS 1501 (part 1): 1984.
The serrated lock washer shall be supplied in natural black finish unless otherwise specified by the purchaser. At the request of the purchaser, the serrated lock washer may be phosphate, tinned, galvanized, nickel plated, copper plated, cadmium plated, etc.