Cylinder Cover Bolts and Nuts - Main Engine and Propulsion

High-strength studs or bolts and matching nuts used to clamp a marine main-engine cylinder cover to the cylinder frame or liner assembly. They maintain combustion-gas sealing under high cyclic pressure and thermal loading.

ProShipWorks provides end-to-end support to source and supply Cylinder Cover Bolts and Nuts for marine vessels, ship operators, industrial facilities, maintenance teams and procurement departments.

Last updated: October 11, 2026

Product Information

Product Name	Cylinder Cover Bolts and Nuts
Product Category	Main Engine and Propulsion
Product Reference	8
Brands / Manufacturers	MAN Energy Solutions, WinGD, Wärtsilä
Unit of Measure	Set

Key Features

Key Feature
1. High tensile and fatigue-resistant alloy-steel construction
2. Engine-specific thread, length and seating geometry
3. Designed for high cyclic combustion and thermal loads
4. Controlled preload by hydraulic tensioning or specified tightening procedure
5. Supplied with traceable material and inspection documentation when required

Applications of Cylinder Cover Bolts and Nuts

Application
1. Cylinder cover fastening on low-speed two-stroke propulsion engines
2. Cylinder head fastening on medium-speed marine main engines
3. Main-engine overhaul and replacement of damaged or elongated fasteners

Models & Manufacturers

Model	Manufacturer
MC/MC-C/ME/ME-C engine-family cylinder cover stud and nut	MAN Energy Solutions
X and X-DF engine-family cylinder cover stud and nut	WinGD
RT-flex and RTA engine-family cylinder cover stud and nut	WinGD

Technical Specifications

Model	Specification	Value	Unit
MC/MC-C/ME/ME-C engine-family cylinder cover stud and nut	Compatibility	Engine type, bore and build-number specific	—
X and X-DF engine-family cylinder cover stud and nut	Compatibility	Engine type, bore and serial-number specific	—
RT-flex and RTA engine-family cylinder cover stud and nut	Compatibility	Engine type, bore and serial-number specific	—

Standards, Certifications & Class Approval

Review the available standards and approval information relevant to the product. Actual certification, material traceability, inspection and classification requirements depend on the product type, intended application and purchasing specification.

Applicable Standards & Certification	Dimensions, material grade, heat treatment and tightening requirements normally follow the engine maker's drawings and service instructions. Material inspection certificates may be supplied to EN 10204 3.1 or 3.2 when specified; generic ISO, DIN or ANSI fasteners are not automatically interchangeable.
Class Approval	Critical replacement fasteners may require OEM acceptance, traceable certification or approval by the vessel's classification society. Acceptance can involve DNV, ABS, Lloyd's Register, Bureau Veritas or ClassNK according to vessel class and repair scope.

Installation, Maintenance & Safety Information

Installation Notes	Confirm engine type, bore, serial number and part number. Inspect threads and seating faces, use only the specified lubricant, and apply preload in the maker's sequence with calibrated hydraulic tensioning or approved tools. Replace sealing components as instructed.
Maintenance Tips	Inspect for corrosion, thread damage, necking, cracks and permanent elongation during overhaul. Check hydraulic tool calibration and compare dimensions with maker limits. Do not reuse fasteners rejected by inspection or exceeding service-life criteria.
Safety Notes	Depressurize, cool and isolate the engine before work. Release and apply preload in the specified sequence because stored elastic or hydraulic energy can cause injury. Use certified lifting gear and never substitute fasteners of unverified material or dimensions.