Quote Originally Posted by JAZZCNC View Post
No 40mm is too small section and you don't need stainless steel. 60 x 60 x 4mm Mild steel is what you need. If you have a local steel supplier it will be cheaper and if you buy in full lengths which will be aprox 7.5mtrs you'll get if for around £40-50 per length or less. The minimum size would be 50x50x3 and can be bought for around £35 per 7.5mtr length.

If you cut careful you should get away with 1 length.

Would you say that 16mm supported bar is sufficient for my build? In terms of strength and abilities to machine aluminium?