On 25/02/2021 18:28, Tim+ wrote:

I happened to stumble upon an old Hayter electric start lawnmower chucked
into the long grass by a road whilst out for a jog the other day so Ive
brought it home to see if its repairable or has any bits worth salvaging.

I started stripping it down and all the bolts were regular metric sizes
until I came to remove the engine cooling cowling. 10mm socket too big, 9mm
too small.

It did occur to me that they might not be the original bolts so I tried all
the AF and Whitworth spanners that I have. No joy.

Eventually dug out a cheap 9mm open ender spanner that could be forced on
with a bit of percussive persuasion.

Im now inclined to think that they are original as they all match and my
micrometer measures them up at 9.5mm. WTF is the point of that?? How many
socket sets include a 9.5?

I cant believe that a designer decided that 9 mm would be too weak and
that a 10mm would be too cramped for space.

Tim


3/8" is 9.525mm
--
Cheers
Clive