The part numbers are distinguished by an additional letter H, e.g. 20LN = standard duty, and 20HLN = heavy duty. From size M40 all brass metric locknuts are considered to be heavy duty.
Zinc Plated Mild Steel cable gland locknuts: A cost effective alternative to brass locknuts and should be used only in dry, low humidity conditions.
Aluminium cable gland locknuts: Recommended when installing aluminium Cable Glands to prevent the galvanic corrosion which can occur when dissimilar metals are coupled together.
Stainless Steel cable gland locknuts: Corrosion resistant with increased strength at high temperatures.
