DIYbanter - Coach bolts, carriage bolts, coach screws etc.

On 26/09/2017 10:12, Huge wrote:
On 2017-09-26, Graeme wrote:

Just a terminology question really. Yes, I know GIMF, but the use of
names seems random at best.

Coach screw - tapered screw thread, hex head. Screw thread may be all
or part of the shaft. To screw into material.

Coach bolt - parallel thread, along all or part of shaft, to be secured
with a nut. Head may be hex or domed - or is one a carriage bolt?

Some coach bolts have slotted heads - as used in greenhouses?

Some have a square rather than hex head.

Then there were bolts to attach car chrome bumpers. The heads were less
domed. Think Anglias, Cortinas etc.

Doubtless there are permutations I have forgotten, or never noticed.

Are they all coach bolts, except the ones that are coach screws?

Bolts are only threaded part-way along the shank. If they are threaded
all the way along, they're a machine screw. A man in a brown coat patiently
explained this to me in a splendid little hardware shop about 3 decades
ago.

Not a shop with a counter 3 score years ago?

--
Michael Chare