How are nuts (as in nuts and bolts not the type you eat) manufactured.?

Question

this is for a manufacturing and materials course work, so the manufacturing process needs to be known.

Answer 1

They are made on a screw machine, generally. This is actually a type of lathe, with multiple heads; one for each operation.

A nut starts life as hex stock. It is threaded and parted from the stock (parting is plunging a tool from the outside diameter straight through to the center of the part).

The parts is then "deburred" in a machine.

Production rate is extremely high - that's why these things are so cheap, unless they are graded or heat treated.

Answer 2

Nuts are made in specialized machining centers called screw machines. These machines can make all sorts of parts from bar stock, not necessarily threaded. In the past, they were purely mechanical, cam-driven machines built on lathes, but now its all CNC. There are 3-8 axis machining centers for high-precision and throughput manufacturing of fasteners and . They are probably the most expensive NC machines out there.

As for processes, the nuts are turned from bar stock, drilled, tapped, and milled. Some machines do it all on one spindle with a multi tool turret and others use multiple spindles.

There is usually some further processing such as deburring, electroplating, heat treating etc...

Check out:

http://www.omni-turn.com/
they have a lot of info on screw machines including some videos;

and

http://www.productionmachining.com/
which is an online magazine and always has articles about screw machines.

Answer 3

I would start by referencing ASTM specifications. For High strength bolts used for buildings and bridges the ASTM #s are A325 or A490 for bolts, F436 for Nuts. The specs will outline the process requirements for the manufacturers. You might get some good info from manufacturers websites such as Lincoln structural bolt, birgingham fastener and EDSCO. Hope this helps.

Answer 4

i suppose the processes are different for different types of nut/bolt.
Here's a useful site though:
http://www.boltscience.com/pages/glossary.htm

Answer 5

start with a hexagonal bar - then drill a hole down the middle - then tap your thread.
Then cut off all them nuts.

Bolts are usually made by rolling or pressing.

Answer 6

first they melt down a type of metal, then they puor it into a mold and lett it cool

Answer 7

the would probably shell them wash and clean them then roast/cook them

dont quote me on that thought