Machine screws and screw-machined components can be made from steel, stainless steel, aluminum, brass, copper, bronze and other materials. The right choice depends on the part’s required strength, corrosion resistance, machinability, finish, operating environment and cost.
There is also an important distinction: screw machining isn’t limited to making screws. It is a precision manufacturing process used to produce custom parts such as fittings, shafts, pins, bushings, inserts, connectors and other components from bar stock.
At Avanti Engineering, these parts are manufactured to customer drawings and specifications for high-volume OEM production.
What Materials Are Commonly Used for Screw-Machined Parts?
The most common choices include:
- Carbon and alloy steel
- Stainless steel
- Aluminum
- Brass
- Copper
- Bronze
Avanti machines a broad range of grades within these material families. The specific alloy should be chosen based on the performance requirements of the finished component—not simply the general type of metal.
Steel
Steel is widely used when a component requires strength, durability or wear resistance.
Avanti machines carbon and alloy steels including 1018, 1215, 12L14, 4140, 4340 and 8620, among others.
Some grades are selected for easier machining and efficient high-volume production, while others provide higher strength or can be heat treated for demanding applications.
Steel is commonly used for parts such as shafts, pins, bushings, fittings and industrial hardware.
Stainless Steel
Stainless steel is often specified when corrosion resistance is important in addition to strength.
Grades machined by Avanti include 303, 304, 316, 416, 420, 440 and 17-4 stainless steel.
Different grades can behave very differently during machining. A material that provides greater corrosion resistance, for example, may not machine as efficiently as a free-machining stainless grade. That tradeoff can affect tooling, cycle time and finished-part cost.
Aluminum
Aluminum is lightweight, corrosion resistant and generally well suited to precision machining.
Avanti machines aluminum alloys including 2011, 2024, 6061, 6262 and 7075 in various tempers and conditions.
The correct alloy depends on the required balance of strength, machinability, weight and environmental performance. Aluminum can also be anodized or otherwise finished when specified on the drawing.
Brass
Brass is particularly well suited to high-volume precision turning because many brass alloys machine efficiently and can produce clean finishes.
Avanti machines multiple brass grades, including C360 free-cutting brass and C693 lead-free brass, along with other standard and low-lead alloys.
Common screw-machined brass parts include fittings, inserts, connectors, bushings, valve components and electrical components.
Copper and Bronze
Copper and bronze may be specified when a component requires properties such as electrical or thermal conductivity, corrosion resistance, wear resistance or low-friction performance.
Avanti’s raw material capabilities include alloys such as C110 copper, C145 tellurium copper and C544 phosphor bronze.
Because properties vary significantly by alloy, drawings should identify the specific material rather than simply calling out “copper” or “bronze.”
How Does Material Choice Affect Machining Cost?
The least expensive raw material does not always produce the lowest-cost finished part.
Material selection can influence:
- Cutting speed and cycle time
- Tool wear
- Dimensional consistency
- Surface finish
- Heat-treatment requirements
- Plating, anodizing or other finishing
- Secondary machining
- Inspection requirements
These differences become especially important in high-volume production, where even a small change in cycle time or tooling requirements can affect thousands or millions of parts.
When design requirements allow more than one material option, reviewing the print with the manufacturer before production can help identify opportunities to improve manufacturability or reduce total part cost.
What Material Information Should Be on a Machining Drawing?
For an accurate quote and repeatable production, specify the exact material grade, alloy, temper or condition whenever applicable.
The drawing and RFQ should also identify requirements such as:
- Critical dimensions and tolerances
- Surface finish
- Threads and special features
- Heat treatment
- Plating, coating, anodizing or passivation
- Material certifications
- Traceability requirements
- Inspection or documentation requirements
Providing this information up front helps the manufacturer select the appropriate equipment, tooling, secondary processes and inspection plan.
Choosing the Right Material for High-Volume Machined Parts
The right material is the one that meets the functional requirements of the component while supporting reliable, cost-effective production.
For OEMs, that means considering more than strength or raw material price. Machinability, tolerances, secondary operations, production quantity and quality requirements all affect the final manufacturing process.
Avanti Engineering has manufactured custom screw-machined and precision-turned components since 1972. Our high-volume machining capabilities support recurring production requirements from approximately 1,000 pieces to millions, backed by ISO 9001:2015 quality controls and material and process traceability.
Have a part ready for production? Send Avanti your print and annual usage requirements for review and quoting.