How Much Is Brass and How Is It Made with CNC Machining?(castijg Nydia)

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Brass is a metal alloy made up of copper and zinc. The proportions of copper and zinc can vary to create different types of brass alloys with differing properties, but typical brass is 67% copper and 33% zinc.
Brass is highly malleable and has a golden yellow color, making it popular for decorative applications, musical instruments, and plumbing fixtures. It is also an excellent material for CNC machining due to its softness and machinability. But how much does brass cost and how is it machined using CNC technology?
Cost of Brass
The cost of brass varies based on the form it is purchased in, the alloy, and current market prices for copper and zinc. Brass stock for machining, such as rods, bars, and sheets, generally ranges from $3 to $8 per pound.
Here are some example brass costs:
- Brass rod (1” diameter), $4-$6 per pound
- Brass sheet (1/8” thick), $3-$5 per square foot
- Naval brass (rod), $5-$7 per pound
- Commercial bronze/brass (rod), $3-$4 per pound
Brass is pricier than carbon steels but less expensive than stainless steel or aluminum. Costs can fluctuate with the commodity markets for copper and zinc. Times of high demand or material shortages can drive brass prices higher.
CNC Machining Brass
Brass is an excellent choice for CNC machined parts due to its softness, machinability, and corrosion resistance. It can be precisely machined to tight tolerances while maintaining a smooth surface finish. Common CNC machining processes for brass include:
Milling - CNC milling machines use rotating cutting tools to remove material and cut brass stock into finished parts or products. Milling allows for complex part geometries.
Turning - CNC lathes spin brass stock while stationary cutting tools shape the material. Turning is ideal for making rotationally symmetric parts or applying detailed features to a part's outside diameter.
Drilling - CNC machining centers can accurately drill holes in brass using specialized drill bits. Holes can be machined to tight diameter and position tolerances.
Tapping - Tapped holes for threads can be added to brass parts using CNC equipment. This allows fasteners or other threaded components to be assembled into the finished brass part.
Counterboring/Countersinking - CNC counterboring and countersinking creates angled openings for fastener heads or other flush mounted features on brass components.
Engraving - Decorative engraving like text, logos, or patterns can be added to brass parts using CNC engraving techniques.
CNC machining makes it cost effective to produce custom brass parts in a wide range of geometries, even in small to medium batch sizes. This makes brass a popular choice for prototypes, small production runs, replacement parts, and custom fixtures.
Advantages of CNC Machined Brass Parts
Here are some of the benefits of using CNC machining processes to fabricate brass components:
- Excellent dimensional accuracy and repeatability. CNC machining brass can hold tolerances up to +/- 0.005 inches.
- Detailed features and complex geometries can be machined that would be infeasible with manual methods.
- No shape limitations - CNC machining can produce simple to very complex 3D brass parts.
- Fast turnaround on production. CNC automation makes brass parts in high volumes.
- Reduced scrap rates relative to manual machining methods. CNC has very high yields and material utilization.
- Smooth surface finishes. CNC machined brass can achieve surface roughness down to 32 microinches or less.
- Does not require expensive casting dies or injection molding tools, ideal for prototype or low volume production applications.
- Allows parts consolidation. CNC can machine brass to combine multiple components into one integrated part.
Types of Brass Used for CNC Machining
The most common types of brass alloys used for CNC machining include:
- 360 Brass – The most popular because of its excellent machinability, good formability, and low cost. Runs at high machining speeds.
- 260 Brass – Also called naval brass. More resistant to corrosion and dezincification compared to 360 brass. Good for parts exposed to salt water.
- 230 Architectural Brass – Provides good corrosion resistance and attractive yellow color. Used for decorative building products.
- 385 Brass – High strength brass used for turned parts and bushings that need good wear resistance.
- 353 Manganese Bronze – Stronger than other brasses with excellent wear properties. Used for marine hardware.
Brass rod, bar, and plate stock for CNC machining is readily available from metal suppliers in these common alloys. The specific alloy can be selected based on the mechanical, corrosion resistance, and appearance needs of the application.
Cost Saving Tips for CNC Machined Brass Parts
Here are some tips to help reduce machining costs when ordering CNC brass parts:
- Use standard brass alloys and stock sizes to avoid special order material surcharges
- Specify larger batch quantities to benefit from volume production efficiencies
- Allow some flexibility in tolerances - precision costs money
- Standardize features across parts in a product line to maximize CNC program reuse
- Minimize secondary operations like plating or finishing which add costs
- Reduce part handling by designing components that machine completely in one setup
- Consolidate multiple parts into single CNC machined components when possible
- Work with your machinist to review manufacturability and identify any design changes that could reduce CNC cycle times
- Take advantage of rapid prototyping services to test a design before committing to production
With forward planning and good communication with your machinist, it’s possible to get high quality brass parts CNC machined at very competitive prices. The automated precision of CNC makes brass an accessible material choice for creating durable and attractive components. CNC Milling CNC Machining