6061 round bar TIR

[3strucking]

Is it normal for round bar stock to have a TIR of .007 ? I checked my chuck and it is .0005 TIR.

 

[ghostdncr]

That pretty much mirrors my experience with the stuff. Some is better than others, but I've ran across a few sticks that were out of round by substantially more than .007" and I have no idea what would be an average mill tolerance would be on aluminum round bar.

 

[Cobra]

Around here I certainly don't expect the bar to be round from the supplier.
Always order a little oversize and turn to dimension.

 

[dennys502]

Actually its amazing it comes out as good as it does. I had several shapes I designed and used in my business and they were very consistent.
Extruded aluminum doesn't really have any support as it comes out of the die and moves down the line.

 

[Rustrp]

Actually its amazing it comes out as good as it does. I had several shapes I designed and used in my business and they were very consistent.
Extruded aluminum doesn't really have any support as it comes out of the die and moves down the line.

Your design and your die with thousands of feet run through it would be like new compared to the stock mill dies. Add that to the calculations made and the $$ added to the bottom line when mill tolerances move towards their profit.

 

[Rockytime]

I have never seen aluminum rod to be accurately round nor is steel perfect. There are exceptions like drill rod which is pretty true. Roll pins are ground accurate.

 

[3strucking]

i guess that's decent then.

 

[dennys502]

Your design and your die with thousands of feet run through it would be like new compared to the stock mill dies. Add that to the calculations made and the $$ added to the bottom line when mill tolerances move towards their profit.

Actually there was roughly 680,000 ft that we ran through the die. We purchased the die but they maintained it for us.
I started out with Alumax until they moved to Yankton, South Dakota then I switched to Crown Aluminum.
The Aluminum went into these paint chip displays we built for several different companies.

 

[Rustrp]

We purchased the die but they maintained it for us.

That's the key, maintenance. I haven't had dies made but I have worked with a customer's material who had their dies made and the accuracy over stock material is huge. All the defects are not related to the die but when it comes to measurements the die is usually the root cause. The means to hold closer tolerances with electronic measuring systems has resulted in material being produced that measures towards the low end of tolerances and this is true especially in sheet product.