Watts Shop Performance
About Us
Engine Components
Friends of the WSP
True Billet Steel Rods
            True billet rods are fairly uncommon in todays marketplace.
Manufacturing begins when rough shapes are flame cut from a plate of
premium quality forged high carbon steel (usually SAE 4340), then
finish machined to the required final specifications. Similar to cutting a
pattern from a sheet of cloth, manufacturers benefit from true billet rods
because they do away with the need to make expensive forging dies.
These dies can cost between $35,000 and $45,000 a pair and several may
be needed to fit all the various applications in the hot rodding galaxy.
On the contrary, the dimensions and physical characteristics of a true
billet rod are only limited by the size of the plate it will be cut from.        

        Although the rolling process that creates the plate of parent
material gives a uniform, longitudinal grain flow with excellent
molecular bonding properties for outstanding strength, there is one
minor shortcoming. True billet rods lack the circular grain flow inherent
to the big end of forged steel rods. Instead, the longitudinal grain flow
continues undisturbed throughout the shoulder and the cap sections.
This does compromise some strength, but industry experts say it is a
minor issue and is responsible for, at worst, 15% reduction in the
ultimate hoop strength of the bearing hole.                                            

        On the positive side, true billet rods are inherently free from the
surface degradations caused by the forging process. A fully machined
billet rod has virgin, high quality material of uniform composition all the
way from the core to the external surface. This makes it more resistant
to the formation of cracks, a detail that more than makes up for the
stubborn grain flow at the big end.