Hub thread pattern

[Dan Case]

Originally Posted by Kit Coyle

Will the "55" thread pitch steel knock off fit on a "60" pitch ERA six pin hub? Are
the hub, wheel and knock off bevel angle the same ? When did Halibrand
make the forged aluminum spinners with the small word "Halibrand" on each
of the three ears? I have the P.S. Engineering FIA wheels and the aluminum
"Halibrand" spinners as supplied by ERA.

Question 1: Me, I have no idea. I work only with the original designs and specifications.

Question 2: 1963-67 A) Probably as close as Halibrand Engineering could, they made the wheels and racing KOs. Putting machinist dye on one or the other and running them together shows a pretty good broad interaction. B) Depending on car type and wheel type the Shelby race team used nuts with two different size tapers over the 1965-67 time frame that I know of. Lots of factors come into consideration including but may not be limited to wheel design, wheel hub thickness, diametric “size” of the threads, hub length, and how many thread turns were on a given hub.

Question 3: As far as I can tell the aluminum blanks forged by Harvey Aluminum and the forged steel blanks of undetermined origin (which the Halibrand name in each wing) came out in either late 1963 or early 1964. I have not found either part’s original drawings. The Shelby race team previously used small cast steel KOs supplied by Ted Halibrand that had no markings on them except an X-ray inspection approval ink stamp when brand new. The cast steel parts with short arms were not tough enough for the big metal hammers race teams typically used; the arms broke off. I looked at one unrestored Cobra racer with cast steel nuts decades ago with two arms of three missing at one front corner.

Note 1: Over the past few decades several individuals or companies have created aluminum, steel, and stainless steel KOs marked with the Halibrand name. Just having “HALIBRAND” text on a part does not mean it was made by any version of the Halibrand company. Indeed, there are some rather fragile cast aluminum KOs out in public marked as being Halibrand.

Note 2: There are numerous genuine 1960s parts produced by Halibrand around in forged steel and aluminum that have been polished and or polished and chrome plated where the HALIBRAND text was removed during polishing.