PDA

View Full Version : Which Bronze for Leadscrew Nut?



gzig5
08-18-2006, 04:51 PM
I need to make new nuts for the cross, compound, and leadscrews on my lathe and need help selecting the material. I know that 360 brass can be used, but SAE660 bronze is better. What about aluminum bronze (Ampco18 or 954)? I understand it is harder, but does it machine better or worse than 660? I plan on milling the stock to shape and then tapping with a tap made from the leadscrew material. Leadscrew will be 4140.
Greg

tattoomike68
08-18-2006, 04:58 PM
I would go for the aluminum bronze. it machines nice, a bit tough. I seen it used on large nuts to adjust a big press break in parallelism , it is good stuff.

Brass is realy best used for ornamental parts , bronze is what you want for bushing and nuts.

SGW
08-18-2006, 05:08 PM
I'd definitely go with bronze, not brass.

Millman
08-18-2006, 05:09 PM
Bronze. Ampco.

Evan
08-18-2006, 05:11 PM
If you are going to tap aluminum bronze you will need to properly harden the tap. Make the tap with a very long lead in, at least a couple of inches.

Millman
08-18-2006, 05:14 PM
Yes, because tapping large diameters is tricky. I call any tap over 1" large.

topct
08-18-2006, 05:15 PM
The only thing that 360 brass is good for is bells and monkeys balls.

Get either of the other stuff. Just think "sharp tool".

lazlo
08-18-2006, 05:40 PM
To add to the consensus: SAE 660 Bronze would be good, Aluminum Bronze even better (higher wear resistance), but Aluminum Bronze is a bitch to tap.

I like to single-point aluminum bronze...

gzig5
08-19-2006, 12:55 AM
Thanks for the replies. I think I'll go with SAE 660. It will probably outlast me, and if it doesn't I can always make new nuts. There should also be less wear on the leadscrew and I think the nut should be the sacrificial part.

YankeeMetallic
08-19-2006, 02:59 PM
I would go bronze 660 "Oilite". Will yours look similar to these? I just did them myself. The stuff machines well, but don't use Koolmist. It creates a glue with the oil in the bronze and is a bitch to get off of your lathe when it dries. You can machine it dry, but it is smoky.
http://i41.photobucket.com/albums/e254/YankeeMetallic/BronzebearingsOilite.jpg

Millman
08-19-2006, 03:30 PM
Fine work, YM, Sorry about the gib remarks; Was in a rather bad mood at the time.

YankeeMetallic
08-19-2006, 05:39 PM
Fine work, YM, Sorry about the gib remarks; Was in a rather bad mood at the time.
No sweat Mill. We all have bad days. I appreciate the comment.