Kibblewhite Precision Machining was the major supplier for
such high-performance distributors as RC Engineering and many others.
Many years later, materials and manufacturing procedures have progressed to a point that these studs are the best on the market.
After some extensive research and development, Cycle X has teamed up with a leading US manufacturer to develop cylinder studs that out-perform all others.
Crafting the studs from premium US-milled, heat-treated and certified Chromalloy Steel (AISI 4130 series) was a no-brainer.
The Honda CB750s (1969-’78) use an 8mm stud, threaded into an aluminum case. Cycle X sought out a stud with a minimum tensile strength of 125,000 psi.
A cylinder stud that grew without yielding and “proofing” the load was essential.
The target was not the strongest stud, but rather the best designed stud the industry has to offer. The decision to design and manufacture ASTM A320 Grade L7B
studs was now underway.
Material was located at a US vendor and purchased. Certification was required at the time of purchase and the added cost was not as important as the
guarantee of the material specifications.
The process to manufacture these studs would be world class and no exceptions were allowed. Rolled threads, radii ground at the minor diameters at the last thread,
interference fit case end threads, special call-out pitch diameter for the nut end and the complete body of the stud was to be ground to remove “Notch Sensitivity.”
You will not find these cylinder studs anywhere else.
From Will Kibblewhite himself:
Premium performance studs made from US-milled, heat treated and certified 4130 Chromalloy Steel for Honda SOHC CB750s from 1969-‘78.
Both ends of these studs have been rolled and not die cut or single pointed. Rolled threads produce the strongest possible thread.
When a thread is hydraulically roll-formed the material is crushed between hardened steel dies under hydraulic force which disrupt and forms a work-hardened-thread.
Additionally, the pitch diameters of both ends of the stud are controlled to produce an interference fit for the case end and a “special” fit on the nut end.
Finally the body of the stud is centerless ground to remove “notch sensitivity”/surface irregularities in which a stud is likely to fail under stress.