Crankshaft Bolts

Bolt used for fastening crankshafts.

Bolts used for tightening timing belt pulleys-dampers and FEAD (Front Engine Accessory Drive) accessory components. May be individual bolts ranging from M12-M16, or multiple smaller bolts, usually 4-6 to M8-M10.

Flywheel Bolts

Bolt used for fastening flywheels or crankshaft flexplates.

Bolts used for tightening single or dual mass flywheels paired with manual transmissions, or automatic gearbox connection plates.

Con Rod Bolts

Bolt used for fastening connecting rod caps

The con rod cap bolts must be subject to at least two screwing operations during the productive cycle of the engine and must therefore be engineered to guarantee a more constant distribution of the axial load.

Main Bearing Cap Bolts

Bolts used for fastening bearing caps, they ensure correct operation of the engine crankshaft.

Bolts used for fastening the various components of the lower part of the engine and which constitute half of the main bearings (main bearing caps, half blocks, complete banks).

Cylinder Head Bolts

Bolt used for fastening engine heads, they ensure a perfect gasket seal

Bolts used for fastening engine cylinder heads, usually in a number of 2x no. cylinders+2. They must exert an axial load allowing a steady contact pressure to be maintained on the head gasket, such as to ensure that cylinders are perfectly sealed and therefore avoiding pressure losses in the combustion chamber and preventing any pressurized burned gases from leaking to coolant conduits.


POLYDRIVE® is the most advanced and revolutionary driving system in fasteners history,
it's the evolution of the cylindrical head bolt with a hexagon socket.

Type of screw with a special dual purpose spline-shaped drive. Given the same applied force, it ensures more compactness and excellent driving using its specific key. Used for assemblies of critical parts in very compact modern engines, particularly for installing heads.

Hexagon Socket Head Bolts

The bolt that has made us famous in Italy first and then in the World.

Type of bolt with a compact cylindrical head and hexagon socket, may be combined with a shank formed by a helical spiral which works by distributing loads on the shank itself, thus increasing elasticity.