4.14.9 CHASSIS GENERAL â—Š NOTE: All chassisâ€™ built to the appropriate SFI specification for the class are permitted. Unless specified otherwise, all tube shall be CHS (Circular Hollow Section) of minimum sizes as detailed in the Material Selection Chart. Mild Steel tubing must be a minimum of CDW (Cold-drawn Welded) or CDS (Cold Drawn Seamless) tubing manufactured to AS/NZS 1163: 2009 standard (Cold-formed structural Steel hollow sections) or equivalent standard as a minimum. Frames fabricated from Mild Steel tubing are required to have gusset plates added at weld major junctions. Gusset plates are recommended for use on CM4130 frames. All new fabricated chassis must be inspected in an unpainted/ un-wrapped state by an ANDRA Technical Inspector, and the details listed in the Vehicle Logbook. Tubing that does not bear CM4130 markings will not be accepted as such. For homologation, documentation should be provided to ANDRA Technical detailing the material used and relevant material property values including Material Designation, Yield Strength (MPa), Tensile Strength (MPa) and Elongation %. The tubing must be bent by a cold working process (mandrel bending or drawn over die bending) and have a minimum bend radius of three times the material diameter. No section of the frame, rollcage or chassis may be electroplated. Electroplating of non-structural components is permitted. Painting, clear coating, powder-coating or oiling are permitted. Refer Chassis, Chassis General. All welding of CM4130 must be by the Gas Tungsten Arc Welding (TIG) process. Gas Metal Arc Welding (MIG) or TIG welding is recommended for Mild Steel tube, and is mandatory for the attachment of rollcage sections. Grinding of welds is prohibited. All butt welds must have visible reinforcement and excessive grinding of welds is not permitted. Where bolted connections are permitted, all bolts must pass through welded sleeves in tube sections to prevent crushing or elongation, and be fitted with locknuts. A welded flat surface should be used under the head of each bolt and nut, where they bear on a tubing section. A minimum bolt diameter of 10 mm (3/8 inch) must be used. In all applications, the minimum distance between holes in rollcages/ bars for the attachment of materials to rollcages/ bars with the use of rivets, or any other fasteners, is 25 mm (1 inch). Any hole drilled in a main hoop or brace must be fitted with a welded bush, the wall thickness of which must be equal to or greater than the drilled tube. All fasteners used must be of Grade 8 or equivalent property class. Fine thread fasteners are recommended due to their increased shear strength. All welding consumables must be properly matched to the welding process and base material used. Where fitted, skid plates must be attached to engine plate or frame. Must be at least 3 sq inch in contact area, located below the bottom of the oil pan, and designed to come in contact with the ground before the Frame-Rail. Wheels are not permitted in lieu of skid plates.