Dimensions, tolerances and general requirements for metric series crinkle washers for use with metric threaded fasteners in the range 1.6 mm to 20 mm diameter inclusive.Cross References:BS 21BS 856Supplement No. 1 to BS 1157BS 1449:Part 4BS 1580BS 1706BS 2870BS 3401BS 3643:Part 1BS 3643:Part 2BS 3643:Part 3BS 4168BS 4183BS 4185:Part 1BS 4185:Part 2BS 4186BS 4190BS 4219BS 4320BS 4377BS 4439BS 4464BS 9001DIN 128DIN 137