Industry
Special fasteners for energy and power plant engineering
Conventional power plants: reduced-shank bolts and casing bolts for steam and gas turbines, hydropower and generators
Industry we supply today
Conventional power plants: reduced-shank bolts and casing bolts for steam and gas turbines, hydropower and generators
Turbines and generators combine high temperatures, high speeds and continuous operation over decades. Casing joints, bearing pedestals, couplings and valves are clamped with reduced-shank bolts and studs that must withstand temperature cycling during start-up and shutdown and retain their preload. RS Randack manufactures these fasteners to drawing for steam turbines, gas turbines, hydro turbines, generators, boilers and power plant valves, in creep-resistant and high-temperature steels.
Typical parts
- Reduced-shank bolts to DIN 2510 and to drawing, with spacer sleeves and cap nuts for casing joints and flanges
- Studs and threaded studs in 21CrMoV5-7 (1.7709), 40CrMoV4-6 (1.7711) and X22CrMoV12-1 (1.4923) to EN 10269 for service up to superheated-steam temperatures
- Coupling bolts and fitted bolts for shaft couplings between turbine and generator, with tight fits and rolled threads
- Long tie rods and tension bolts, typically up to 3,500 mm long, turned on the CNC turning centre with a steady rest
- Stainless and high-strength versions for hydropower, with impact testing for cold sites
Requirements and documentation
- Elevated-temperature yield strength and creep behaviour ensured by material selection to EN 10269; properties verified in our own laboratory on a test bar from the same heat
- Threads rolled after quenching and tempering for fatigue strength under vibration
- Crack testing by magnetic particle inspection on 100% of safety-critical parts, ultrasonic testing of raw material with large cross-sections
- Inspection certificate 3.1 or 3.2, customer audits and witnessed inspections on site
What RS Randack brings
In-house forge for heads and collars with uninterrupted grain flow, CNC turning centres up to 300 mm diameter and 3,500 mm length, thread rolling also in the quenched and tempered condition, materials laboratory with tensile testing up to 3,000 kN, Charpy impact testing down to –70 °C and microstructural examination, anti-friction coatings for assembly in high-temperature applications. Sub-sectors: steam and gas turbines, hydropower, generators, boiler construction, power plant valves, district heating, power plant services and overhauls.
Nuclear technology
Nuclear facilities, decommissioning and interim storage are subject to their own rules: KTA 1401 qualification, test scope per operator specification, documentation for each dimension. How RS Randack meets these requirements is described on the Nuclear technology page.
Frequently asked questions
Questions and answers about energy and power plant engineering
Which materials are suitable for turbine bolts?
Creep-resistant quenched and tempered steels such as 21CrMoV5-7 (1.7709) and 40CrMoV4-6 (1.7711) for temperatures up to about 500 °C; above that, high-temperature martensitic steels such as X22CrMoV12-1 (1.4923) and nickel-based alloys. The choice depends on temperature, preload and service life.
Does RS Randack manufacture spare parts for overhauls at short notice?
Yes. Rush orders are one of RS Randack’s strengths: you will hear from us within a few hours. In many cases, delivery within 24 hours is possible.
Request fasteners for turbines and generators
Urgent? You will hear from us within a few hours.