Thread: Are the TD5 nuts and bolts metric, imperial or both?

Originally Posted by Blknight.aus

M(x) is a bolt shank size (aka a touch larger than the major diameter of the thread) and in the metric (and the UNC/UNF) world of bolts is absolutely nothing to do with head size.

The shank size is different to the head size but there are international standards which define the standard head size for m(x) fasteners, so there is a defined relationship between shank size and head size. Under the ISO standard an M8 fastener has a head size of 13mm for example.

RAVE indicates that ISO standard is used for metric fittings on the D2.

BoltHeadChart.png

Edit: The DIN sizes are actually the same as the ISO precision metric sizing. Ignore the ISO/ANSI sizes as this seems to refer to a different standard.

Bet I can name 3 bolts on any td5 that do not comply to that standard. And thats without even thinking about it or going off the engine.
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Originally Posted by Blknight.aus

Bet I can name 3 bolts on any td5 that do not comply to that standard. And thats without even thinking about it or going off the engine.
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Hi Dave,

It looks like there are ISO Standards and ISO Standards.

BS-3692-2001 ISO metric precision hexagon bolts, screws and nuts gives head dimensions that look to be the same as DIN rather than Australian Metric or ANSI/ISO.

BS-3692 lists:

M5: 8mm
M6: 10mm
M8: 13mm
M10: 17mm
M12: 19mm
M16: 24mm

The 17mm/19mm seems more in line with the bolts on the D2, than 16mm/18mm.