This week- (Mar 1st week)
Handle nutsThis week I needed to remove the handle, filter and (importantly) original throttle + cable. I also removed the chute cover to protect it from damage. When I went to remove the handle bolts I found this wonderful improvisation or engineering/industrial design. I can only assume it was the "Nyloc" before "Nyloc' was invented. Someone's had a good 'go' at one in the past...
![[Linked Image from i1222.photobucket.com]](http://i1222.photobucket.com/albums/dd490/pitrack_1/Eric%20Anderson%20Mower/handle_nuts_zpsspmnaied.jpg)
Amazing!!! Am I right or can someone correct me?
Those turn out to be 'Philidas turret nuts', which are still made by the original company in the UK;
http://www.philidas.com/The Whitworth hex sizes follow a unique dimensional progression, which doesn't fit in with either of the AF [SAE or ISO metric] systems. Part of the reason for this, is that Sir Joseph Whitworth's system was the very first designed, standardised fastener thread and hex system to exist - he introduced it in 1841, under the limitations of the materials and available bar stock sizes of the time.
Some of the history:
http://www.enginehistory.org/british_fasteners.shtml
