Top 4 Tips for Machining Dura-Bar
Cost savings generated by using Dura-Bar as a replacement for steel have been well documented. Dura-Bar's superior machinability and minimal need for deburring results in decreased cycle times and more parts per hour. Using Dura-Bar also yields significant improvements in tool wear, chip control and surface finishes. Dura-Bar weighs 8% less than steel and is quieter in operating parts due to its vibration damping quality.
Dura-Bar's superior machinability stems from the graphite contained in its microstructure. Graphite enhances machining by acting as a natural chip-breaker. It reduces friction on the insert and dissipates heat, thereby extending tool life. Graphite also improves overall wear resistance in the final application.
The key to getting the most benefit and cost savings from Dura-Bar's inherent advantages is to check your machining methods for the following, and make some slight adjustments if needed. Specifically:
1. Use the Correct Inserts - A common mistake is to substitute inserts not specifically designed for the cutting of Dura-Bar, or designed specifically for steel. Any general purpose grade isn't going to perform. Standard coated carbide inserts developed specifically for cast iron are best. Also, for best results when drilling, use carbide tooling. The proper coating is critical for optimal performance.
2. Skip the Chip Breaker - Since typical machining of Dura-Bar does not require any elaborate chip breaker design, satisfactory results can be achieved. In certain instances, geometries used in chip breaker designs may be used to achieve desired surface finishes.
3. Use the Right Coolant - Based on experience, the best results are achieved with either a water soluble or semi-synthetic coolant at a 4-6% level of concentration. This is because the water draws out more heat, and the 4-6% concentration adds both lubricity for friction reduction and additional corrosion/rust protection.
4. Run it Faster - Dura-Bar's dense, fine-grained microstructure makes it especially clean and consistent, allowing for faster machining speeds. The absence of sand and carbides typically found in castings for example, allows the use of higher surface footage (sfm) with confidence, and without sacrificing your current feed rates.
All of these recommendations are made assuming you have a sound and rigid set-up.
To learn more about machining Dura-Bar, download our Machining Guide. The guide includes brief versions of the tips above, as well as machinability ratings and wear rates of specific grades of Dura-Bar vs steel grades, recommended machining speeds and feed rates, and shows how Dura-Bar chips are consistent, controllable and lead-free.
Dura-Bar Metal Services also offers free machining support. For more information on machining Dura-Bar or to learn more about our free machining support services, please contact your Dura-Bar Metal Services Account Manager or call 888-387-2227.