Brass - Recommended in securing brass Cable Glands and Accessories to a gland plate or into equipment. In metric thread form CMP offers brass locknuts in a choice of standard duty and heavy duty options for sizes up to and including M32. 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 - A cost effective alternative to brass locknuts and should be used only in dry, low humidity conditions. Aluminium - Recommended when installing aluminium Cable Glands to prevent the galvanic corrosion which can occur when dissimilar metals are coupled together. Stainless Steel - Corrosion resistant with increased strength at high temperatures. Please refer to ordering reference numbers (page 139), e.g. 20LN4 for M20 Stainless Steel Locknut, 050NPTLN4 for 1/2” NPT Stainless Steel Locknut.