The answer provided below in July of 2017 is no longer accurate and up-to-date as the manufacturer has changed the design of this product. Effective April of 2019 the Rockwood SP1080 is the knife insert only and does not include the conehead machine bolt which is the part number Rockwood SP1039. We have left that old answer intact as it does apply to the original question when you are using a combination of the SP1039 and the SP1080
*** Original out of date answer: ***
The Rockwood SP1080 1/4 - 20 Cone Head WS Now consists of two individual components as seen in the photograph here :
View Image
The Rockwood SP1080 consists of the Rockwood SP1039 as seen here :
And now this new knife style thread wood compatible bolt that will insert onto the machined end of the SP1080. According to rockwood this new knife style insert bolt does not have an individual part number.
Your original question is what is the overall length I would say that our overall length is approximately 1"