best for turning

[naughtyboy]

rang up for some 45mm solid rd today asked if i wanted black or bright.

i need to ends down to 36mm as making some rollers.

which is best to get?

cheers

 

[Paul.]

Bright would be better for rollers, its diameter will be more accurate and cleaner, the bar will be straighter too, if you are buying full lengths brights will come in 3mtr random lengths, black will be 6 mtrs long

 

[piman]

hello NB,

I was taught not to put black bar in a chuck as it strains them, not so bad if using a four jaw, but I would prefer bright for both types.

Alec

 

[BrokenBiker]

I have used both in lathe and mill, both worked out fine

 

[Lawnmowerboy]

Black bar will not run as true in a 3 jaw. Not sure what you mean by straining though?

 

[mr_splatter]

I'm guessing that because Black bar is not as round as bright it might strain a self centering chuck. If turning the outer skin of black bar can be hard and take the edge off your tools but it does have less internal stresses than bright but this usually can causes problems if machining unequal amounts off sides as in milling. Reducing diameter in lathe should be ok. I use Black because it's cheaper and I'm tight!

 

[Lawnmowerboy]

But a 3 jaw will always clamp up on all 3 points. thep roblem with black is it doesn't cut as nicely as a freecutting mild steel such as EN1A leaded. Turns no worse than Com. grade 3B though.

 

[langy]

I much prefer BMS for machining or welding, Its not that much dearer really

 

[Lawnmowerboy]

Oh and don't buy leaded if you want to weld it...