ASTM A193 Heavy Hex Nut Length 5000mm Ptfe Coated Stud Bolts

Stud bolt ASTM A193 B7 -16 "Thread to Thread" Class 2A c/w 2 Heavy Hex Nut ASTM A194 Gr.2H Class 2B

ASTM A193 B7 B7M Fluorocarbon coated PTFE Stud Bolts Full threaded Rod with ASTM A194 2H Heavy Nuts

The method of applying the coating shall ensure that damage through delayed embrittlement (hydrogen embrittlement) is avoided. This is particularly important in the case of high tensile steels of Grades B, C and D with tensile strength > 1000 N/mm². The application should be carried out in accordance with ASTM B841 and associated standards. The surface shall be treated with chromate conversion treatment according to ASTM B841 Section 4.

The PTFE top coat for bolting components shall be Xylan 1070® (or) equivalent. The selected material shall contain polytetrafluorethylene together with polyamide /polyimide ester and colouring pigment and shall be the base cure type. The selected material shall withstand the temperature range of -50°C to + 200 °C.

The dry film thickness of the PTFE coating on the bolting component shall not be less than 25 microns and not greater than 40 microns. The coating shall be applied in accordance with ASTM D823. The application of coating shall be applied with a minimum of two (or) more layers.

The fluorocarbon coating system (PTFE) shall be tested in an ASTM B117 salt fog chamber for 3000 hours.

A corrosion resistance test for PTFE coat over Zn-Ni plated stud-bolts shall be carried out in accordance with ASTM B117 (salt spray test) for the time duration of 3000 hrs (minimum).