Offshore & Subsea Bolting & Fasteners

Torqbolt has gained a market reputation for supplying and manufacturing Offshore and Subsea Bolting. Low Temperature and Sour Service Environments are some of the areas of Offshore Bolting which requires compliance with Pressure Equipment Directive (2014/68/Eu) and NORSOK requirements. American Standard of Mechanical Engineers (ASME) has recommended special grades for Offshore & Subsea Bolting.

Offshore & Subsea Bolting Materials

Fastener Type Material Specification H2S Size
Bolts and studs Low Alloy steel ASTM A320 L7 No Up to М65 & 2.5"
Bolts and studs Low Alloy steel ASTM A320 L7M Yes Up to М65 & 2.5"
Nuts Low Alloy steel ASTM A194 7M   Yes Up to М65 & 2.5"
Bolts, studs, nuts and washers Low Alloy steel ASTM A320 L43 No Up to M100 & 4"
Bolts, screws, pins, studs Austenitic corrosion Resistant Stainless steel EN ISO 3506-1 А4-80 Yes М6 to М16
Nuts Austenitic corrosion Resistant Stainless steel EN ISO 3506-2 А4-80 Yes М6 to М16
Bolts, nuts, washers Austenitic corrosion Resistant Stainless steel ASTM A453 Gr. 660D Yes No restrictions
Bolts Nickel Alloy ASTM F468M UNS N06625 Yes No restrictions
Nuts Nickel Alloy ASTM F467 UNS N06625 Yes No restrictions
Bolts, nuts Nickel Alloy API 6ACRA3 UNS N07718 Yes No restrictions

Offshore & Subsea Bolting Surface Coatings

Fasteners with Special Coatings are used for Subsea & Offshore Applications where the Bolting is subjected to a highly corrosive environment.
The following Surface Treatments are used for Subsea Bolting:

Offshore & Subsea Bolting Products