Screw is 97mm overall with a thread form unique to Stanley.
(RESELLERS TAKE NOTE: FOR ACCEPTABLE QUANTITIES WE CAN WHOLESALE THESE - PLEASE EMAIL YOUR INTEREST)
SOME HISTORICAL NOTES
For more than 150 years Stanley planes held an unmatched dominance in woodworking handplanes. They invented a proprietary thread form which was copied by many other makers in this market in particular Record, a British based competitor. Some component parts and spare blades are therefore compatible.
This spare fits the handle of certain of the 'bench' planes. A bench plane is the name given to a range of general purpose planes which were numbered in ascending size from a #1 then #2, #3, #4, #4 1/2, #5, #5 1/2, #6, #7 and #8. The bolded codes remain in production from Stanley although their future availability is uncertain.
To complicate matters Stanley now ship planes with a mix of metric and Stanley threads although I have yet to have any call for metric fasteners at time of writing these notes in August 2018.
Stanley Bailey Exploded Parts Diagram