Tubular arms

Hard chrome plated tubular arms

Chrome plated tubes are stored in steel grade E355 and in stress relieved condition (condition +SR = stress relieved). Other steel grades and delivery modes are available on factory order. The tubes are manufactured accor­ding to the requirements of the European standard EN 10305-1.

The thickness of the chrome coating on chrome plated tubes depends on the diameter of the rod; for diameters less than ø20mm the thickness of the chrome coating is min. For diameters less than ø20mm and ø20mm and above the minimum thickness is 20µm. A nickel chrome plated option is also available. The chrome plating gives the products excellent corrosion and wear resistance. They are commonly used as components for hydraulic and pneumatic cylinders.

The outer diameter tolerance is f7 (except f8 for smaller diameters).

Chrome-plated tubes are available with different levels of corrosion resistance, measured accor­ding to ISO 9227. The salt spray test can be carried out either by means of a Natural Salt Spray Test (NSS) or by means of an Acid Accelerated Salt Spray Test (AASS).

The basic stock grade is tested accor­ding to the NSS and is guaranteed by Rating 9 after 200 hours of salt spray (with the exception of the smallest diameters after 72-120 hours). Rating 9 allows a maximum of 0.1% of the rod surface to be rusted after the specified number of hours. In nickel chromium plated tubular bars, a nickel layer is also applied under the chromium layer, which prevents the penetration of moisture permeating the micro-cracking of the chromium layer into the base material, thus significantly improving corrosion resistance. Depending on the quality, the NSS 1500h Rating 10 and AASS 500h Rating 10 are the best.

For dimension tables and further details of the steel grades we offer, please refer to the downloadable product catalogue.