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Collection, Preservation and Display of Old Lawn Mowers

ATCO 12" MOWER

I am in the process of restoring a 1947? Atco 12" 2 stroke mower, what I would like to know is the thread on the screws, they look like BSF but they are not,they are not BSW either? what could they be?

Ray

Forums

wristpin Thu, 03/07/2014

AS far as I know, a machine of that date would have BSF and BSW threads, it was not until the 60s that Atco adopted UNF/UNC. However if you are sure that the fine threads are not BSF (or UNF) I suppose that there is a possibility that they are Cycle Threads as used on some JAP engines.

gtc Fri, 04/07/2014

Like Wristpin, I would expect them to be Whitworth. Those on my 1949 12 inch certainly are. In fact I had to buy a set of Whitworth spanners for the job.

Suggest you use a thread gauge on them. Perhaps somebody has changed them over the years?