# Making a Metric M68 - 3.0  nut - Aluminium



## Brent H (Jul 11, 2022)

So my one son has a buddy that owns a small car and it has a decorative nut that screws on to cover the hub bolts.  The original is a blue anodized aluminium nut with an M 68 -3.0mm pitch internal thread. Total outside diameter of 88 mm.  This was a mission for Mr Imperial and Miss Metric!!!

I sized everything on the one lathe:






And got things to proper dimension. The bore is extended to allow threading and then I under cut a relief at the back for the thread cutter to run out to.  The nut flange is only 4mm thick so I wanted to avoid crushing the nut.  That can be down right painful.  So I mounted up the internal threading bar:




 And dialled the sized blank in on the metric lathe 4 jaw.   I have no threading dial so basically had to leave Miss Metric engaged - not married, but a long term engagement in the 3.0 mm pitch and then shut down, reverse and go at it again.  Miss Metric was working pretty hard indeed!!  

After cutting threads to supposed depth I set the blank onto the mill with my rotary table and cut the flats.  Back to the lathe to bevel the edges and part off the nut. 






I luckily have a 3.00 thread file so I cleaned up some of the threads for a great fit:




 Completed:





Now that Miss Metric has made a big nut I will have to get on making the threading dial to keep things interesting!!


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## architect (Jul 11, 2022)

I like how you just have stock material that size laying around!


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## David_R8 (Jul 12, 2022)

Well done!


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