|A2 Stainless Steel
|Imperial - BA
Spring washers are locking washers that are used when there is a need to prevent a fastener from loosening as a result of vibration. They are also often called split lock or split ring washers.
A spring washer has a split in the washer section that when tightened each side of the split bites into the nut and the mounting surface. This “bite” prevents any anti-clockwise rotation from occurring under vibration.
The term “square section” refers to the end section of the split in the spring washer.
An imperial washer can be used in conjunction with all types of non-metric threads including UNC, UNF, BSW, BSF, BA etc.
BA thread (British association) is a rarely used thread that was once commonly found on small instruments and models. Still sparingly used in some industries such as metering equipment manufacturing and optical equipment.