CHROME PLATED SHAFT 4140 - 70.00dia
4140 is a 1% Chromium - Molybdenum high tensile steel supplied in the hardened and tempered, cold drawn or turned precision ground, polished, chromeplated and final polished condition, with a typical base metal tensile strength of 850 - 1000 Mpa, plus a typical hard chrome plated surface of HV 1000 - 1150.
Characterised by an extremely smooth surface finish with excellent wear and corrosion resistance, coupled with a base material giving high strength and good impace properties, plus good machinability.
4140 hard chrome plated bar is used extensively by the hydraluic and pneumatic industries, and is employed by other industry sectors for a wide range of applications requiring higher strength.
Typical applications are: Agricultural Equipment, Hydraluic Cylinders, Hoists, Jacks and other Lifting equipment, Machine Tools, Mining and Earth Moving Equipment, Pumps, Valves, Waste Disposal Transport and Equipment etc.
COLOUR CODE: Dark Green End Caps.
TYPICAL BAR LENGTHS: up to 18dia: 2000 - 3600. 19.05 to 25dia: 4000. Over 25dia: 6000. (approx only - 100mm unchromes surface at each end)
PACKAGING: Supplied in cardboard tubes for protection.
MACHINING: - 4140 hard chrome plated bar has very good machinability, similar to 4140 uncoated bar. Machining however should commence beneath the chrome plating, or at the unchromed surface at the end of the bar. To protect the polised chrome surface, soft materials such as copper, aluminium or mild steel should be used as clamping materials and any particles of hard chrome should be removed immediately to avoid scratching. Otherwise all machining operations should be carried out satisfactorily.
WELDING: - Welding 4140 hard chrome bar in the hardened and tempered as supplied condition is not recommended and should be avoided if at all possible, as the mechanical properties will be altered within the weld heat affected zone. If however welding is really necessary the follow procedure may be taken as a guide only.
WELDING PROCEDURE: The cardboard tube protecting the chrome plating should first be removed from the heat affected area otherwise it can cause some corrosion of the plating due to fumes emitted.
Welding should always be carried out using low hydrogen electrodes - please consult you welding consumables supplier.
POST WELDING: - Maximum cooling rate 95degc/hour down to 95degc, followed by cooling in still air. NB,. No draught. It is recommended that the weld area if possible is wrapped in a heat resistant blanket or buried in sand, dry lime etc.

Category: MERCHANTS & BRIGHTS