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CNC Workholding: Fixtures, Soft Jaws and Vacuum Clamping Guide
CNC workholding is the system used to locate, support and clamp a workpiece during machining. A machine tool may have excellent positioning accuracy, but the finished part will still be wrong if the stock shifts, lifts, vibrates or distorts in the fixture. Workholding therefore affects tolerance, surface finish, cycle time, tool access, operator safety and the cost of every part.
The right solution may be a standard milling vise, machined soft jaws, a fixture plate, a three-jaw chuck, a collet, a vacuum table or a custom multi-part fixture. The best choice is not simply the device with the highest advertised clamping force. It must establish the drawing datums repeatably, oppose the actual cutting forces, avoid deformation and expose the required features to the tool and inspection equipment.
This guide explains the main CNC workholding methods, locating principles, clamp placement, soft-jaw design, vacuum-clamping limits, thin-part strategies, five-axis considerations, inspection, cost and the information buyers should include in an RFQ.
What Does CNC Workholding Need to Do?
A reliable workholding system performs four connected functions:
Locate the workpiece. It places the part in a known position and orientation relative to the machine coordinate system.
Support the workpiece. It resists cutting forces and prevents bending or vibration.
Clamp the workpiece. It maintains contact with the locators and supports throughout the machining cycle.
Provide access. It lets tools reach the required faces without collision or excessive overhang.
These functions must remain stable as material is removed. A rough blank may be rigid at the beginning of an operation but become flexible after deep pockets or thin walls are created. The fixture and machining sequence must work together.
Why Workholding Determines CNC Part Quality
Workholding errors can create:
Incorrect datum relationships
Position, perpendicularity, flatness or profile failures
Tapered walls and bores
Steps between machining setups
Chatter and repeating surface marks
Crushed, dented or visibly marked surfaces
Thin-wall distortion after unclamping
Burrs caused by vibration or incomplete support
Tool or holder collisions
Part movement and serious safety hazards
Inconsistent results between the first and later parts
A stronger clamp does not automatically improve accuracy. If force is applied in the wrong direction, a flexible component may conform to the fixture during machining and spring back afterward. Good workholding uses enough force to resist the process while controlling where that force enters the part.
The 3-2-1 Locating Principle
The 3-2-1 principle is a useful way to understand how a prismatic workpiece is constrained.
Three contact points establish a primary plane and restrict three degrees of freedom.
Two contacts establish a secondary plane and restrict two more degrees of freedom.
One contact establishes a tertiary plane and restricts the final degree of freedom.
In practice, the primary contacts may be parallels, rest buttons or a fixture surface. The secondary contacts may be a fixed vise jaw or locating pins. The tertiary contact may be an end stop.
The principle does not mean every fixture must visibly contain exactly six individual buttons. It means that the locating scheme should constrain the required motion without conflicting contacts. Over-location can cause rocking or force a variable casting against too many rigid points.
The drawing datum reference frame should guide the fixture concept. Review the Aluprototype article on GD&T datums for CNC machining for the relationship between functional datums, machining setups and inspection.
Location Is Different from Clamping
Locators establish position. Clamps push the workpiece against those locators. Treating a movable clamp as the primary locating element can reduce repeatability because clamping travel, friction and part variation change where the component stops.
A common milling-vise arrangement uses the fixed jaw as the principal side locator and the movable jaw to apply force. Parallels or machined steps support the bottom face. A work stop controls the longitudinal position. If the movable jaw lifts the part, the workpiece may no longer sit on the supports.
Design clamp force so it drives the component into the intended datum contacts. Side force that also creates an upward moment is undesirable unless a pull-down mechanism controls it.
Main CNC Milling Workholding Methods
Standard machine vises
A precision vise is flexible, familiar and quick to set up. It is effective for rectangular stock, prototypes, first operations and many second operations. Hardened jaws tolerate rough stock, while machinable jaws can match finished geometry.
Check jaw alignment, bed cleanliness, parallel condition and actual clamping height. Grip too little material and the part may pull out. Grip too much and tool access may be lost. Tall parts may need additional support or reduced cutting force.
Soft jaws
Soft jaws are machinable jaw inserts made from aluminum, mild steel or another suitable material. A pocket, step, radius or contour is cut into the jaws to match the workpiece. Increased contact area improves support and repeatability while reducing visible marking.
They are especially useful for:
Second-operation machining
Round or irregular components
Thin or delicate parts
Castings and near-net-shape blanks
Repeat batches that need fast loading
Parts requiring controlled orientation
Kurt Workholding describes soft jaws as a way to hold irregular or delicate parts using a machined matching contour, improving contact, rigidity and repeatability. Its official soft-jaw workholding guide provides practical examples.
Fixture plates
A fixture plate attaches to the machine table and provides a pattern of threaded and locating holes. Parts, stops, clamps, vises and custom nests can be arranged on the plate. Fixture plates are useful for large components, multiple small parts and jobs that do not fit a standard vise.
Use dowels, keys, bushings or a qualified reference feature when the plate must return to a repeatable position. Bolts provide clamping force but should not be assumed to provide precise location through normal clearance holes.
Toe clamps and strap clamps
Low-profile clamps can hold large plates, castings and weldments directly to a table or fixture. The clamp should push the workpiece into its supports, and the stud, step block and contact pad must be sized for the load. Keep clamps clear of toolpaths and allow for a safe machining sequence when clamps must be moved.
Never remove or relocate a clamp during a cycle without a proven sequence that maintains sufficient restraint. A part can shift as residual stress is released or as another clamp is loosened.
Dovetail workholding
A small dovetail is machined into sacrificial stock or a designated gripping area. A compact fixture grips that feature, leaving most sides of the part accessible. Dovetails are popular for five-axis machining because they reduce obstruction and allow multi-face access.
The design must leave enough material around the dovetail to resist cutting loads. The sacrificial feature is removed in a later operation. Buyers should understand that extra stock, preparation and a second operation affect cost.
Expanding mandrels and ID clamping
An expanding mandrel locates and grips through a bore, exposing the outside diameter and end faces. It can provide good concentricity when the reference bore is accurate and strong enough for expansion force.
Thin rings can distort under excessive internal pressure. Bore size variation, contact length and wall thickness must be considered. For very flexible rings, near-full-circumference support may be needed.
Modular and zero-point systems
Modular systems combine subplates, risers, pallets, vises and locating modules. Zero-point systems clamp and locate fixture pallets through repeatable interfaces, reducing indicating and setup time.
Jergens describes modular workholding as a combination of subplates, risers, fixture plates and top tooling that brings the spindle close to the workpiece. Its modular workholding overview explains how quick-change foundations support flexible setups.
These systems add initial hardware cost but can reduce changeover time for recurring work, automated cells and machines serving many part families.
CNC Lathe Workholding Methods
Three-jaw power chucks
Three-jaw chucks are common for round and hexagonal stock. Standard hard jaws grip rough material quickly. Machinable soft jaws are preferred for finished diameters, thin parts and second operations requiring better concentricity or contact.
Jaw engagement, workpiece projection and chuck pressure must suit the cut. Excessive projection increases bending and vibration. Insufficient contact or incorrectly bored jaws can allow the part to move.
Collet chucks
Collets provide near-circumferential contact and fast loading over a limited size range. They are useful for bar work, small diameters, thin tubing and production runs. A collet must match the workpiece size and shape; closing too far outside its intended range reduces contact and accuracy.
Soft chuck jaws
Lathe soft jaws are bored or turned under simulated clamping load so the final gripping surface matches the workpiece. They may grip an outside diameter, expand into an inside diameter or support an end face.
Haas notes in its official lathe chatter troubleshooting guide that incorrectly bored jaws can let a part move, creating accuracy and chatter problems. The company recommends machining jaws near their intended operating position and checking for contact gaps.
Pie jaws
Pie jaws provide almost continuous circumferential contact. They are useful for large-diameter, thin-section or noncylindrical parts that would distort or mark under narrow jaw contact. More contact distributes force but does not remove the need to limit chuck pressure.
Mandrels, arbors and centers
Mandrels locate through bores, while centers support long shafts using center holes. A tailstock or steady rest can reduce deflection of slender workpieces. Center condition, alignment and lubrication must be controlled where applicable.
Custom chucks and fixtures
Eccentric, asymmetric, cast or delicate components may need custom nests, faceplate fixtures or balanced dedicated chucks. Rotating fixtures require particular attention to mass distribution, retention and safe spindle speed.
How to Design and Machine Soft Jaws
Soft jaws are simple in concept but easy to misuse. A reliable process includes the following decisions.
Choose jaw material
Aluminum jaws are easy to machine and suitable for prototypes, soft materials and many delicate parts. Mild-steel jaws provide greater wear resistance for harder workpieces and larger production quantities. Nonmetallic inserts may be appropriate for highly cosmetic surfaces, but strength, temperature and coolant compatibility must be verified.
Preload the jaws before machining
Vise or chuck jaws deflect under clamping force. Machine the gripping pocket while the jaws are loaded in a condition that represents actual use. Vise jaws may be preloaded with a spacer, while lathe jaws commonly use a boring ring or support slug.
If jaws are cut unloaded, the pocket may not contact evenly when production clamping force is applied.
Match the functional locating surfaces
Do not copy the entire CAD shape without deciding which faces should locate the part. A small number of purposeful contacts are often more repeatable than a full nest that traps chips or conflicts with part variation.
Control pocket depth and grip height
The jaw step should provide sufficient vertical support without blocking the cutter. Grip height depends on cutting force, material, jaw contact, part geometry and operation. A tall or heavily cut component may need more engagement than a light finishing operation.
Add loading clearance
Provide enough clearance for easy loading, chips and part variation while maintaining the intended contacts. Sharp internal corners in a jaw pocket may prevent a workpiece radius from seating fully.
Include stops and poka-yoke features
End stops, asymmetrical pins or shaped nests can prevent reversed or misoriented loading. Error-proofing is especially important when opposite sides look similar but have different features.
Mark and control jaw identity
Record the part number, operation, vise or chuck position and program revision. A pair of jaws may look reusable but no longer match after the master jaw, mounting position or machining origin changes.
Verify jaw contact
Use appropriate contact checks, feeler gauges or indicator measurements to confirm seating. Inspect the first part after unclamping, not only while it remains forced into the jaws.
Vacuum Workholding for CNC Machining
Vacuum fixtures use pressure difference across a sealed area to hold a workpiece. They are useful for broad, flat parts that are difficult to grip mechanically, including plates, panels, sheet, plastic and nonferrous materials.
How holding force is generated
Available holding force depends mainly on pressure differential and effective sealed area:
Holding force = pressure differential × sealed area
This means vacuum is often effective on a large panel but weak on a small part. Grooves, holes, porosity, leakage and reduced contact area lower real holding capacity. The calculation must include a suitable safety factor and the direction of cutting forces.
Advantages of vacuum clamping
Excellent access to the top surface
No jaw marks on outside edges
Distributed force that can reduce local deformation
Fast loading for flat parts
Suitable for nonmagnetic materials
Useful for sheet and plate machining
SCHUNK states that its vacuum clamping technology is intended for flat-bottomed workpieces and can support quick setup and low-deformation clamping.
Limitations and risks
Holding force decreases with smaller sealed area
Through-holes and open toolpaths can break the vacuum zone
Rough, porous or warped surfaces may leak
Coolant and chips can damage seals or block passages
Heavy side milling may exceed frictional resistance
A pump or seal failure can release the part
Thin parts can be pulled into an uneven fixture surface
Use pressure monitoring, zoned fixtures, mechanical stops and a risk-appropriate backup strategy. A vacuum fixture should not rely on hope that the remaining gasket area will be enough after a contour breaks through.
Gasket and zone design
Place gasket grooves to preserve effective area through the planned toolpath. Isolate unused regions so leakage from an empty zone does not reduce the entire system. Support the workpiece between gasket boundaries to prevent bowing.
Sacrificial and porous spoil boards
Routers often use a sacrificial board that permits through-cutting while distributing vacuum. Its permeability, flatness and remaining thickness affect performance. Resurfacing restores a consistent plane but gradually changes fixture height.
Magnetic Workholding
Magnetic chucks can hold ferromagnetic parts with broad access and distributed force. They are used for suitable steel and iron components in milling, grinding and related processes.
Performance depends on material, contact area, thickness, pole arrangement, air gaps and cutting-force direction. Thin parts may not provide enough magnetic path, and nonferrous materials cannot be held directly. Residual magnetism and chip attraction also need consideration.
Adhesive, Tape and Low-Melt Workholding
Special tapes, adhesives, waxes and low-melt alloys can hold thin or delicate parts when mechanical clamps obstruct access. These methods require controlled surface preparation, temperature, cure, removal and cleaning.
The holding method must be compatible with coolant, cutting heat, material and subsequent finishing. Residue can interfere with anodizing, painting, bonding or medical cleaning. Use a validated process, not an improvised adhesive on a high-force operation.
Workholding Thin Plates and Flexible Parts
Thin components can bend under both cutting and clamping forces. A successful plan controls support, sequence and final inspection state.
Support close to the cutting zone
Place supports beneath the active area rather than only at the outside corners. A broad plate supported at four distant points can vibrate or dish in the middle.
Distribute clamping force
Use wider contacts, soft jaws, vacuum or multiple low-force clamps instead of one concentrated load. Clamps should seat the part without forcing it to match an inaccurate fixture.
Leave temporary stock
Tabs, ribs, an outer frame or thicker sacrificial material can preserve stiffness during roughing. Remove temporary features in a controlled finishing operation.
Balance material removal
Alternate sides or rough symmetrically when residual stress is a concern. Allow the part to relax between stages and re-establish datums before final finishing.
Inspect after release
A flexible part may measure well while clamped and change after removal. Define whether the drawing requires free-state or restrained-state inspection. Document restraint when the part is intentionally measured in a fixture.
Manage chatter
Fixture support, cutting-force direction and tool engagement must work together. The article CNC Chatter: Causes, Prevention and Surface Finish Guide explains how workholding stiffness interacts with the tool, machine and workpiece.
Five-Axis Workholding
Five-axis machining requires access from multiple directions while keeping the fixture clear of the spindle, cutter and holder. Compact vises, dovetail fixtures, raised pallets and custom low-profile clamps are common.
Key considerations include:
Maximum tool and holder envelope at every rotary position
Fixture, spindle and table collision checks
Sufficient gripping feature below the finished geometry
Center-of-gravity location and rotary-axis load
Rigidity of stacked risers and adapters
Chip evacuation when the part is tilted
Probe access to datum features
Repeatable orientation between operations
A tall stack may improve access but reduce stiffness. Simulate the complete machine, fixture, holder, tool and workpiece, not only the finished CAD model.
Multi-Part and Production Fixtures
Production fixtures aim to reduce handling time while maintaining consistency. Holding more parts is not always more productive if tool travel, chip accumulation or loading complexity increases.
Fixture capacity
Balance the number of parts against cycle time, tool life, operator access and inspection frequency. A fixture full of parts can create a large batch of defects before a worn tool is detected.
Common versus individual clamping
One bar or hydraulic circuit can clamp several parts quickly, but variation in one workpiece may reduce force on another. Equalizing mechanisms or individual clamps can improve consistency.
Chip management
Include escape paths, air or coolant cleaning and surfaces that do not trap chips under locators. Automated loading requires especially reliable chip detection and cleaning.
Quick-change pallets
Offline loading and repeatable pallet location reduce spindle idle time. The economic benefit is strongest for recurring work, short cycles and automated cells. Validate repeatability at the part feature, not only at the pallet interface.
Workholding for Castings, Forgings and Irregular Blanks
Raw castings and forgings vary in size, draft, flash and surface condition. A rigid nest that fits one blank may rock or jam on another.
Use qualified locating pads, adjustable supports and clamps that accommodate expected variation. Three-point primary location is often more stable than a broad nominal surface. Rough operations may create accurate datum pads for later fixtures.
Define the machining allowance and casting-datum scheme in the drawing or process plan. Insufficient stock in one area cannot be corrected by clamping the blank harder.
Avoiding Clamp Marks and Cosmetic Damage
Mark all cosmetic and sealing surfaces on the drawing. A supplier can then select jaw material, contact location and protective handling intentionally.
Possible controls include:
Machined aluminum soft jaws
Larger contact areas
Replaceable polymer or brass pads
Clamping on sacrificial stock
Lower force with additional support
Vacuum clamping
Protective cleaning and packaging
Soft contacts can trap chips, which then imprint the part. Clean jaws and contact pads between cycles. A protective insert that hides a chip can be worse than a clean metal jaw.
Datum Transfer Between CNC Setups
Many parts require two or more operations. The second fixture must locate from features created or preserved in the first operation.
A strong datum-transfer plan:
Creates stable locating surfaces early.
Protects those surfaces from burrs and damage.
Uses repeatable contacts in later fixtures.
Controls which setup establishes each critical relationship.
Provides probe or indicator access for verification.
Minimizes long tolerance chains between unrelated setup references.
If a critical hole pattern is machined in one setup and a mating face in another, the datum transfer must protect their relationship. Consider machining the features together or using a common verified reference where possible.
How Clamping Force Causes Distortion
Clamping force produces elastic deformation even in apparently rigid parts. The displacement may be tiny, but it matters when tolerances are close.
Common examples include:
A thin ring becoming three-lobed in a chuck
A plate bowing across parallels
A hollow housing collapsing under vise force
A split component closing at the gap
A thin wall leaning away from a side clamp
A plastic part creeping under sustained load
Reduce distortion by increasing contact area, supporting opposite the clamp, lowering pressure, changing force direction or adding more lower-force contacts. Machine critical features under a clamping condition representative of their final free state whenever possible.
Workholding and Tolerance Capability
The drawing tolerance, fixture repeatability, machine accuracy, tool deflection, thermal behavior and measurement uncertainty all consume part of the available error budget. A vise repeating closely does not guarantee the finished feature repeats if chips collect under the part or the stock varies at the gripping surface.
Use broad general tolerances for noncritical features and tighter limits only where function requires them. The CNC machining tolerances guide explains how geometry, material, setup count and inspection method affect achievable results.
Inspecting and Validating CNC Workholding
First-piece verification
Inspect the first completed part after it is unclamped. Include relationships affected by fixture location, such as position, parallelism, perpendicularity and setup-to-setup dimensions.
Repeatability study
Load, clamp, measure and unload the same part several times. This can reveal variation caused by chips, operator technique, stop contact or clamp sequence.
Clamp-force verification
For pneumatic, hydraulic and powered chucks, monitor pressure and verify the relationship between input pressure and actual gripping force according to the equipment manufacturer. Wear, lubrication and mechanism condition affect performance.
Contact and seating checks
Use indicators, sensors, air checks or appropriate contact media to confirm that the workpiece reaches the intended locators. Automation should detect missing parts and incomplete seating when risk justifies it.
Fixture qualification
Measure critical fixture locators, bushings, pallets and datum surfaces. Record the fixture revision and maintenance status. Replace worn components before compensating the CNC program around a deteriorating fixture.
Ongoing process monitoring
Track part results, tool load, probe data and fixture maintenance. A gradual positional shift may indicate locator wear; increasing chatter may indicate lost support or reduced clamping force.
Common CNC Workholding Mistakes
Using clamping force to overcome poor location
If the part rocks, identify the chip, burr, warped blank or conflicting locator. More force may only deform the component.
Locating on an uncontrolled surface
A saw-cut or rough casting surface may vary too much to establish a close-tolerance feature. Create or specify stable datum pads.
Clamping too far from the cut
Long force paths allow bending and vibration. Support and clamp close to the machining zone without blocking access.
Ignoring jaw and fixture deflection
Jaws, plates and risers are not infinitely rigid. Preload machinable jaws and verify behavior under production force.
Allowing chips under locators
One chip can tilt the entire workpiece. Design self-cleaning contact areas and a consistent cleaning process.
Using bolts as precision locators
Standard clearance bolts clamp components but do not normally locate them accurately. Use dowels, keys, fitted interfaces or qualified zero-point elements where repeatability matters.
Over-constraining irregular parts
Too many rigid contacts can make a variable blank rock or force it into distortion. Use defined locating points and adjustable supports.
Forgetting toolholder clearance
The cutter tip may reach the feature while the holder collides with a tall jaw or clamp. Verify the entire assembly.
Measuring only while clamped
Flexible parts can change after release. Inspect in the drawing-defined condition.
Reusing unidentified soft jaws
Old jaws may have been recut, shifted or used on another master jaw. Control part number, operation and orientation.
CNC Workholding Cost Drivers
Workholding cost depends on more than fixture hardware. Important factors include:
Number of machining setups
Blank variability
Part size and rigidity
Required datum repeatability
Tool access and collision risk
Prototype versus production quantity
Custom jaw or fixture design hours
Fixture material and heat treatment
Hydraulic, pneumatic or vacuum components
Sensors and automation interfaces
Pallet or zero-point hardware
Fixture qualification and maintenance
Loading and unloading time
For one prototype, a simple vise and carefully planned tabs may be economical. For thousands of parts, a dedicated multi-part fixture or automated pallet can reduce unit cost even with higher upfront investment.
RFQ Checklist for CNC Workholding-Sensitive Parts
Include the following information with the quotation request:
3D CAD model in STEP or another agreed format
Controlled 2D drawing and revision
Material grade, condition and raw-stock form
Prototype, batch and annual quantities
Functional datum reference frame
Critical tolerances and GD&T controls
Thin walls, flexible regions and distortion concerns
Surfaces that may or may not be clamped
Cosmetic and sealing surfaces
Permitted sacrificial tabs or extra stock
Existing locating holes, bores or datum pads
Free-state or restrained-state inspection condition
Final heat treatment, coating or finishing sequence
Required first-article or dimensional report
Cleaning, marking and packaging requirements
Target delivery date and destination
The broader CNC machining RFQ checklist can help organize CAD data, drawings, materials, quantities and quality requirements.
CNC Workholding RFQ Template
Please quote CNC machining for part [part number and revision] in [material and condition], quantity [prototype and production quantities]. Functional datums are [A/B/C or description], and the critical features are [list]. The part contains [thin walls, deep pockets, flexible plates, irregular cast surfaces or other concerns]. Do not clamp or mark [identified surfaces]. Sacrificial tabs or added stock are [permitted/not permitted] at [locations]. Final processing is [heat treatment/coating/finish], and inspection is required in the [free/restrained] state. Please review the locating scheme, clamp access, deformation risk, operation sequence, inspection method and recommended DFM changes before production.
Frequently Asked Questions
What is the difference between a jig and a fixture?
A fixture locates and holds a workpiece. A jig also guides a cutting tool, traditionally through features such as drill bushings. CNC machining commonly uses fixtures because machine motion guides the tool.
Are soft jaws accurate?
Soft jaws can provide excellent repeatability when machined under proper preload, mounted consistently and kept clean. Accuracy still depends on the master vise or chuck, machine, locating design and workpiece variation.
Should soft jaws be aluminum or steel?
Aluminum is easy to machine and gentle on many prototype parts. Mild steel is more durable for harder materials and larger quantities. The best choice depends on load, wear, marking risk and production volume.
How much of a part should be held in a vise?
There is no universal value. Required grip depends on contact area, material, cutting direction, tool engagement, part height and jaw design. A process engineer should verify resistance to pullout, lift and rotation.
Can vacuum workholding resist side milling?
It can when effective area, pressure differential, friction, stops and safety factor are sufficient. Small parts, leaks and heavy lateral cuts may require mechanical assistance.
Why does a part lift in a milling vise?
Jaw geometry, friction, chips, inadequate seating or the vise mechanism may create upward motion. Use clean supports, controlled clamp direction, appropriate soft jaws and a verified seating process.
Why does a thin ring become out of round after turning?
Chuck force can elastically deform the ring. The part is machined round while clamped but springs into a lobed shape after release. Use lower force, more contact, pie jaws, a mandrel or a different operation sequence.
Do locating pins need clearance?
Usually one round pin and one relieved or diamond pin are used for two-hole location so the fixture constrains position without binding from hole-spacing variation. Exact design depends on datum rules and required repeatability.
Can a fixture use the same datums as inspection?
Often yes, and this can simplify correlation. The physical fixture and inspection setup must still apply the drawing's datum rules correctly and accommodate material-condition requirements where specified.
Is a zero-point system more accurate than a vise?
It provides a repeatable fixture-to-machine interface and faster changeover, but total part accuracy still includes the pallet, top tooling, locators, clamping, machine and process.
How often should fixtures be inspected?
Frequency depends on use, load, material, coolant, tolerance and risk. Critical locators and wear components should be included in preventive maintenance and checked when process data begins to drift.
Can clamping marks be removed after machining?
Light marks may be blended on cosmetic surfaces when permitted, but polishing can change dimensions and texture. It is better to prevent marks with planned contacts and protective handling.
Request a CNC Machining Quote
Reliable CNC workholding begins with functional datums, stable supports, controlled clamp force and enough tool access to machine the part without excessive reach. The fixture should resist real cutting forces while allowing the finished component to return to its intended free shape.
Send your CAD model, drawing, material, quantities, finish and inspection requirements through the Aluprototype request-a-quote page. The engineering team can review soft jaws, vacuum clamping, fixture plates, five-axis access, thin-part distortion and production-fixture requirements before machining begins.