Industry
Special fasteners for shipbuilding and marine applications
Propellers, rudders, shafts and couplings, with class certificates
Industry we supply today
Propellers, rudders, shafts and couplings, with class certificates
Shipbuilding and the marine industry require fasteners that withstand seawater, vibration and sustained loads over the life of the vessel and are certified by a classification society. RS Randack manufactures screws, bolts, nuts and turned parts for propellers, rudder systems, shafting, couplings, engines and deck equipment in stainless, duplex and quenched and tempered steels. RS Randack is approved by Bureau Veritas under Mode II for fasteners from M4 to M200 (scope of approval; production typically up to M180) and turned parts up to 300 mm diameter, and by DNV as a manufacturer.
Typical parts
- Propeller blade and hub bolts in stainless and duplex steels, often with fitted shank and locking device
- Rudder bolts, rudder trunk bolts and coupling bolts for shafting with close-tolerance fit diameters
- Reduced-shank bolts and studs for engines, gearboxes and couplings in 42CrMo4 and 30CrNiMo8
- Deck bolts, anchor bolts and special bolts for winches, cranes and hatch covers
- Turned parts such as bushes, sleeves and pins up to 300 mm diameter
Requirements and documentation
- Inspection certificates 3.2 witnessed by the classification society; Bureau Veritas, DNV, Lloyd’s Register, ABS and others regularly carry out inspections on site, and we hold a stamp authorisation from one society
- Corrosion resistance through the material (1.4571, 1.4462 duplex, nickel-based alloys) or through zinc flake and anti-friction coatings
- Low-temperature impact energy for ice class and cold waters, tested in our own laboratory down to –70 °C
- Crack testing using the dye penetrant method on stainless parts, magnetic particle testing on quenched and tempered steels
What RS Randack brings
Bureau Veritas Mode II approval and DNV Approval of Manufacturer, in-house forge and turning shop for fitted bolts and large bolts, thread rolling up to M180, materials laboratory with full-size tensile testing up to 3,000 kN, witnessed inspections on site and express service for shipyard and dry-dock schedules. Sub-sectors: merchant shipbuilding, naval shipbuilding, yacht building, propeller and rudder manufacturers, marine engines and propulsion, offshore supply vessels, repair yards.
Frequently asked questions
Questions and answers about shipbuilding and marine applications
Which classification societies carry out inspections at RS Randack?
Bureau Veritas, DNV, Lloyd’s Register, ABS, RINA and others: all common classification societies regularly carry out inspections on site in Hagen. The approvals and their validity periods are listed on the Quality page.
Does RS Randack manufacture propeller bolts in duplex?
Yes, stainless and duplex steels are everyday work in our forge, turning shop and thread rolling department, with dye penetrant testing and inspection certificate 3.2.
Request fasteners with class certificates
Urgent? You will hear from us within a few hours.