Metal Cutting in Fabrication and Machining

Metal fabrication and machining are subtractive manufacturing techniques. Subtracting or removing material from metal blocks or sheets must be done skillfully and precisely. Metal cutting may sound like a basic concept, but using the right equipment is critical to the outcome of the metal piece. In this post, we discuss metal cutting for fabrication and machining.

Metal Cutting for Fabrication

Cutting sheet metal is a fundamental process in metal fabrication. Before the sheet metal is bent must be cut. The initial cutting creates the piece’s outline from the sheet, called a blank. Additional cutting is then performed to make holes, notches, venting, and louvers. The metal cutting is done using CNC lasers, CNC punches, and shears.

At CMD, we have various pieces of cutting equipment to meet your fabrication and machining needs.

Hydraulic Shear
A shear is a mechanical cutting method used to cut straight lines and square edges of sheet metal. This is often the first step before moving on to other processes. It may also be used to cut large pieces into small, more manageable sheets.

A shear is a powerful machine driven by a hydraulic (or mechanical) force that rapidly lowers a cutting blade to a stationary lower cutting blade to sever the sheet metal. Shears are rated to cut materials of specific thicknesses and sizes so that the blades are not damaged. The metal is placed in the front-loading area, and a hold-down bar grabs it and secures it while cutting. A back gauge can be set at a specified distance from the shear blade to control the length of the cut and ensure repeatability.

Our shears include the following:

• Cincinnati 3/8″ – 10′ 36″
• Cincinnati 1/4″ – 10′ 36″
• HTC 1/4” Hydraulic 10’

CNC Punch
A CNC punch, very much like the name sounds, uses tooling to punch into the sheet metal. The CNC punch uses a program to tell it how to move on an X and Y axis to accurately position the sheet under the punching ram. Speed, location, and feed rate are controlled via digital communication and the machine’s specialized.

The pattern can be any shape and may be punched entirely through, like holes or perforations; partially punched through, like louvers and vents; or not pierced through the metal at all, like with embossing. For high-volume parts, punching can be very cost-effective. However, for lower volumes, tooling costs may make it cost-prohibitive. Your metal fabricator will help you determine the most cost-effective fabrication method.

Our punches include:

• Amada OCTO 30 Ton CNC 8 Station with Auto Index
• Whitney 50-Ton Duplicator
• Whitney 30-Ton Duplicator
• L&J Punch Press – 90-Ton

Laser Cutting
Another way that metal is cut is with a laser cutter. A highly focused monochromatic, collimated beam supplemented with gas generates intense heat that melts or vaporizes the metal, creating a narrow kerf (cutting path) as it moves. CO2 lasers use carbon dioxide, nitrogen, and helium mixture as media for laser amplification. The laser beam is created by electromagnetically stimulating carbon dioxide molecules, which pass through a series of mirrors that increases its intensity before it is passed through the nozzle.

The edges on a laser cut are smoother, and the setup costs are lower than with a punch. However, laser cutting can leave splatters on the surface that will be removed during deburring.

A laser cutter with flying optics keeps the sheet metal stationary, and the laser moves to cut the metal. A moving material laser moves the material, and the laser is stationary. The flying optics is faster and more versatile because the bulky material is not being moved.

Our lasers include the following:

• Amada F1 – 4000 Watt – Max Sheet Size 120 x 60 – Flying Optics
• Amada Gemini – 4000 Watt – Max Sheet Size 120″ x 60″ – Flying Optics
• Amada Punch / Laser – 2500 Watt LC 2012 C1 NT with Sheet Loader

Metal Cutting for Custom Machining

Since removing material from a metal block is an entirely different process, different equipment is used. Metal machining primarily involves mills, lathes, routers, and waterjet cutters.

CNC Lathe and Turning Centers
A CNC lathe uses a computerized program to precisely rotate the workpiece on a spindle against the cutting tools to perform various operations, such as cutting, knurling, or drilling. The rotating motion of the workpiece makes this process ideal for creating an object with symmetry about the axis of rotation. The key characteristic of a lathe is that material removal occurs rotationally. They are ideal for creating objects like spheres, cylinders, or cones or for making features such as drill holes, bores, and threads.

CNC turning centers are more advanced than CNC lathes. While a lathe is typically a 2-axis machine, turning centers can have up to five and offer more versatility.

Our lathes and turning centers include:

• Mazak QTN450MY 24″ Max Dia. x 120″ Long, 8″ Y-Axis 50HP, 10HP Live Tooling
• Haas SL-30 17” Max Dia. X 34″ Max Length 30HP
• Haas SL-40 25.5” Max Dia. X 44″ Max Length 15″ Chuck 40HP Live Tooling
• Hardinge Super Precision Quest 6/42 Live Tooling Sub Spindle
• Haas SL-20 10.5” Max Dia. X 20″ Max Length
• Bridgeport EZ Path Lathe – Full CNC or Manual Control
• South Bend Manual Lathe 12″ x 50″
• Victor Lathe 16” x 60”
• Hardinge HLVH Tool Room Lathe

CNC Mill
The key characteristic of a mill is that it performs operations in a linear fashion, but it can do so across multiple axes. The CNC mill also gets its direction for how to cut the piece from a program originating from a CAD file. Milling machines can work on 3, 4, or five axes, which provides flexibility depending on the part’s complexity. The milling machine can be horizontal or vertical. Horizontal mills have a horizontal spindle running parallel to the worktable’s surface, and the cutting tool rotates around a horizontal axis to remove material from the part. They have shorter, thicker tools for making deep heavy cuts. With a vertical mill, the head runs perpendicular to the worktable’s surface, and the cutting tool rotates in a vertical spindle to remove material from the workpiece. The cutting tools are long and cylindrical for making shallower cuts on smaller parts.

Tapping, drilling, boring, and reaming milling are common functions a CNC mill performs. They can also perform more complex operations like slot and keyway cutting, planning, and die sinking.

Our milling equipment includes:

• Haas Super Mini-Mill 16” x 12” x 10”
• Haas VF-1 (Vertical) 20” x 16” x 20”
• Haas VF-3 YT/50 (Vertical) 40” x 26” x 25”
• (2) Haas VF-4 (Vertical) 50” x 20” x 25”
• Haas VF-5/40TR Trunnion Mill 38” x 26” x 25”
• Haas VF-6/50 (Vertical) 64” x 32” x 30” 4th Axis Rotary
• Haas VF-7 (Vertical) 84” x 32” x 30” 4th Axis Rotary
• Haas VF-11 (Vertical) 120” x 40” x 30” 4th Axis Rotary – full Renishaw Inspection System on machine
• Haas VF-12 (Vertical) 150” x 32” x 30”
• Haas EC500 (Horizontal) 32” x 20” x 38” with full 4th Axis Rotary System – Pallet Changer
• Haas HS-7R (Horizontal) Machining Center 84” x 66” x 60” – 10,000 lb. table, 4-Axis
• Forest Line Seramil VMC X-236” Y-94” Z-47” 5-Axis Programmable, 2.5 Degree Indexing
• Acer Knee Mill with ‘X and Y’ NC Control
• Chevalier Knee Mill with ‘X and Y’ NC Control
• Forest Liné Modumill VMC X-275″ Y-157″ Z-59″ 5-Axis Programmable, 2.5 Degree Indexing

CNC Router
Like a mill, a CNC router cuts in a linear format but across a larger working area. A router operates at a higher speed than a mill but is primarily used to cut softer metals, such as aluminum. A router’s work envelope size can be quite large and often not enclosed.

Our router:

• AXYZ Pacer 4008 – 48″ x 96″, 2 Heads – 24,000 RPM

Waterjet Cutting
A waterjet uses a high-velocity jet of water to cut through metal. The CNC-controlled cutting machine forces water through a narrow diamond, ruby, or sapphire gemmed orifice at 60,000 Psi to 94,000 PSI, which cuts the metal. The gems are highly resistant to heat, pressure, and corrosion and have a low coefficient of friction, which reduces the possibility of heat being generated from friction and pressure. Sometimes abrasives are used to aid in the cutting process. A Waterjet can easily cut materials up to 12 inches thick.

A waterjet is a cold-cutting process widely preferred in applications where a heat-affected zone around the cut impacts the metal’s microstructure. Waterjet cutting is sometimes referred to as waterjet machining because it can perform the functions of a mill, but so it is faster.

Our waterjet

• Flow 6012 Waterjet – 93,000 PSI, 6′ x 12′ Bed

CMD Are The Metal Cutting Experts

Custom products with tight tolerances are our specialty. We have all the cutting equipment needed to meet your fabricating and machining needs. Beyond cutting, we have invested in equipment and tools to engineer, fabricate, machine, weld, finish, and assemble your project, creating a one-stop-shop of expertise. We also maintain an ISO certification to hold us to the highest standards in manufacturing excellence. Contact us and let us quote your next metal project.