Machining of ZA Alloys
The machinability of the ZA alloys is excellent: faster and easier than any other alloy of comparable strength, including the bronzes. These zinc alloys tolerate wide variations in machining conditions without sacrificing quality.
Iron castings can contain hard spots and sand inclusions that make machining very difficult and costly. Machining zinc foundry alloys is much faster, and tool life is several times longer than cast iron.
Drilling, tapping, reaming and turning
General speed and feed recommendations
Drilling: Drilling speeds in the range 200 to 300 fpm can be used. Feed rates as follows:
Tapping: Cutting speeds of 200 sfm are acceptable for general work.
Reaming: Feeds for reaming are similar to those for drilling. Speeds in the range 100 to 200 sfm are recommended for reaming ZA zinc foundry alloys.
Turning: Speeds and feeds are similar to those listed above for drilling. Reduced speeds and high feed rates improve chip formation.
Milling - Cutting speeds:
Sawing: Bandsaw. Cutting speeds: 300-400 fpm
Grinding: Belts in the 40-80 grit range are acceptable for general work.
Staking: Low speed (e.g. hydraulic) or high speed (e.g. mechanical) presses can be used.