Conformação a Frio vs Usinagem CNC para Porcas Personalizadas: Custo, Resistência, Tolerância e Volume
Choosing between cold heading and CNC machining for a custom nut is not a simple “which process is better?” question. The correct route depends on geometry, material, thread requirement, critical tolerance, sample stage, coating, heat treatment, annual volume and approval risk.
Cold heading is usually a production-efficiency route when the geometry can be formed and volume justifies tooling. CNC machining is usually a flexibility route for prototypes, low-volume orders, changing designs or complex features. Many custom nuts use a hybrid route that combines cold heading with secondary machining, threading, heat treatment, coating or inspection when required.
Cold heading, CNC machining and hybrid routes should be selected by geometry, tolerance, volume and approval stage.
Conceptual manufacturing-route image only; not proof of a specific product model or process approval.
Quick Answer: When Should Custom Nuts Be Cold Headed or CNC Machined?
Choose cold heading when the custom nut has stable geometry, formable features, repeat demand, and annual volume that can justify tooling. Choose CNC machining when the project needs prototypes, low-volume production, frequent design changes, complex side features, tight local machined features, or fast design validation before tooling investment. Choose a hybrid route when the basic blank can be formed but critical features still require machining, tapping, thread rolling or post-process inspection.
The buyer should not ask only “Which process is cheaper?” The better question is: which manufacturing route matches the drawing, function, tolerance, material, coating, volume and approval stage? A CNC sample may help check fit, but it does not automatically represent a cold-headed mass-production part. A cold heading quote may reduce unit cost at volume, but only if tooling, material flow, secondary operations and inspection requirements are feasible.
Why the Manufacturing Route Changes Cost, Strength, Tolerance and Lead Time
Two suppliers may quote the same custom nut differently because they are assuming different manufacturing routes. One supplier may quote CNC machining for a small batch. Another may quote cold heading with tooling for future mass production. A third supplier may quote a hybrid route that combines a formed blank with secondary machining.
If the buyer compares only unit price, the result can be misleading. A low CNC sample price does not always predict mass-production cost. A cold heading quote may include tooling and setup cost that makes the first batch more expensive but lowers unit cost later. A hybrid route may look more complex, but it may be the most realistic way to meet both cost and critical-feature requirements.
For drawing-based parts, the manufacturing route should be reviewed together with the latest drawing revision. This is especially important for porcas especiais fabricadas sob desenho, where the quoted route must match actual geometry, critical dimensions and approval expectations.
Cold heading, CNC machining and secondary operations must be reviewed as a complete process route.
Workflow diagram for process planning; actual route depends on drawing, material, tolerance and volume.
Fator de Decisão
Cold Heading Tends to Fit When…
CNC Machining Tends to Fit When…
Hybrid Route Tends to Fit When…
Geometria
The external shape can be formed consistently
The part has complex or non-formable features
The blank is formable but some features need machining
Volume
Annual demand can justify tooling
Quantity is low or demand is uncertain
Volume is meaningful, but not all features are formable
Design maturity
Drawing is stable and critical dimensions are confirmed
Design is still changing or under prototype review
Design is mostly stable, with selected critical features still machined
Cost structure
Tooling cost can be amortized over repeat production
Dedicated heading tooling is not justified
Forming reduces material waste while machining controls key features
Approval risk
Production-intent forming route can be validated
Prototype route is acceptable for early design checks
Process route must clearly define formed and machined features
Engineering Rule
The process name is not enough for approval. Buyers should request the complete manufacturing route: blank preparation, forming or machining, threading, secondary operations, heat treatment, coating, inspection and packaging when required.
What Is Cold Heading for Custom Nuts?
Cold heading, also called cold forming in many fastener contexts, forms metal at room temperature by forcing wire, rod or a prepared blank into a die. Instead of cutting away most of the material, the process displaces material into the required shape. This can be efficient for high-volume fastener production when the geometry, material and tooling design are suitable.
For custom nuts, cold heading may create the basic nut blank, flange shape, shoulder, projection feature or other formed geometry. The part may still need tapping, thread rolling, trimming, secondary machining, heat treatment, coating and final inspection depending on the drawing.
How cold heading forms the nut blank
In simplified terms, cold heading uses controlled force and dies to move material into shape. The process depends on material formability, blank size, die design, part geometry and process sequence. A custom nut with a simple external shape and stable volume may be a good candidate. A part with thin walls, deep undercuts, difficult side features or very low quantity may be less suitable.
Why tooling matters
Tooling controls the formed shape. Good tooling can support repeatability, but it adds upfront cost and validation work. If the drawing changes after tooling is made, the cost and timing impact can be significant. Buyers should freeze critical geometry and confirm expected volume before choosing cold heading for a custom nut.
Cold heading DFM checks
Before selecting cold heading, the supplier should review whether the nut geometry can be formed without creating excessive material flow risk, thin-wall distortion, die-fill problems or secondary machining burden. The review should include material formability, blank size, wall thickness, flange or shoulder geometry, thread preparation, expected lot size and final inspection method.
Cold Heading DFM Item
Por que é Importante
Needs Confirmation
Material formability
Affects heading feasibility and cracking risk
Material grade, hardness and supplier input stock
Blank geometry
Controls material flow and die-fill behavior
Part drawing, blank size and forming sequence
Wall thickness
Thin areas may deform or require machining
Critical section dimensions
Thread preparation
Thread method affects fit and strength
Thread size, pitch, tolerance and coating condition
Secondary operation need
Special features may not be formed economically
Slots, side holes, shoulders, pilot features and bearing faces
When secondary operations are still needed
Cold heading does not automatically complete every custom nut. Threads, critical flatness, slots, side holes, bearing surfaces, pilot features or special faces may require secondary operations. Heat treatment or coating may also be required depending on material, function and customer specification.
What Is CNC Machining for Custom Nuts?
CNC machining creates features by cutting material with controlled tools. For custom nuts, CNC may include turning, milling, drilling, boring, tapping, threading, slotting or facing depending on the part geometry.
CNC machining is especially useful when the buyer needs a prototype, a low-volume batch, design flexibility or features that are difficult to form. It can also be used as a secondary operation after cold heading.
CNC machining for prototypes and low-volume orders
When a project is still in the design stage, CNC machining can provide parts quickly without committing to cold heading tooling. This is useful for checking assembly fit, thread engagement, bracket clearance, mating part condition or packaging space. For low-volume orders, CNC machining may remain the better route because the tooling cost for cold heading may not be justified.
CNC machining for complex or non-formable features
Some nut designs include shoulders, grooves, slots, side holes, special bearing faces, counterbores or non-symmetric geometry. If those features cannot be formed reliably, CNC machining may be needed. In some cases, the blank can be cold headed first and then machined only where precision or geometry requires it.
CNC machining DFM checks
CNC machining is flexible, but it is not automatically the best production route. Buyers should confirm whether the machined design creates excessive material removal, sharp transitions, weak sections, long cycle time or difficult inspection. A machined feature should support function, not only match appearance.
Good CNC fit
Prototype batches, changing designs, special slots, side holes, shoulders, low-volume service parts and critical local features.
CNC cost risk
High material removal, long cycle time, multiple setups, difficult deburring or large annual volumes.
Approval risk
A CNC sample may not represent a later cold-headed production route unless the route difference is reviewed and accepted.
When machining becomes too expensive for mass production
CNC machining becomes less attractive when every part requires long cycle time, heavy material removal or multiple setups. In high-volume production, the cost of machine time and scrap may exceed the benefit of flexibility. At that point, cold heading or a hybrid route should be reviewed.
Cost Comparison: Tooling Cost, Unit Cost and Annual Volume
Cost comparison must include more than the quoted unit price. The buyer should consider tooling, setup, material utilization, machining time, secondary operations, inspection, packaging, approval documents and expected annual volume.
Tooling cost, unit cost and annual volume should be compared before choosing a manufacturing route.
Conceptual matrix only; actual tooling cost and volume threshold must be confirmed by drawing and quotation.
Why cold heading needs tooling investment
Cold heading usually requires forming tools. These may include dies, punches and related setup. The more complex the geometry, the more carefully tooling must be designed and validated. This makes cold heading less attractive for unstable designs or very small quantities. However, once tooling is validated, cold heading can support efficient repeat production.
Why CNC machining can be cheaper for low volume
CNC machining can be cheaper for low volume because it avoids dedicated heading tooling. The supplier can program the part and machine a small batch from bar, tube or prepared stock. This is useful for prototypes, spare parts, validation samples or short-run projects. The tradeoff is that the unit cost may stay high if the quantity increases.
How annual volume changes the quote
The same part can have two different correct quotes depending on volume. A CNC quote may be reasonable for a small sample batch. A cold heading quote may be more reasonable for stable mass production. A hybrid quote may be best when the part needs both formed efficiency and machined precision.
Fator de Custo
Impact on Cold Heading
Impact on CNC Machining
Pergunta do Comprador
Volume anual
Higher volume helps justify tooling
Higher volume increases machine-time burden
What is the realistic yearly demand?
Tooling complexity
Complex geometry increases tooling cost
Less dependent on forming tooling
Is the design frozen?
Custo do material
Better material utilization may help
Heavy material removal increases waste
Is the material expensive or difficult to machine?
Secondary operations
May be needed after forming
May already be included in machining route
Which features require secondary work?
Tolerance requirement
Tooling validation matters
Local precision may be easier to machine
Which dimensions are critical?
Approval documents
May require production-intent process evidence
Prototype evidence may not represent mass production
Is PPAP or customer approval required?
Cost takeaway: CNC can be the correct low-volume route even when unit price is higher. Cold heading can be the correct mass-production route even when the first quote includes tooling cost. The right comparison is total project cost across sample, tooling, production, inspection and approval risk.
Strength Comparison: Grain Flow, Material Removal and Functional Testing
Strength should not be judged by process name alone. A cold-headed nut is not automatically acceptable for every application. A CNC machined nut is not automatically weak. Strength depends on material, geometry, section thickness, heat treatment, thread engagement, bearing area, coating and functional test requirement.
Formed material flow
In suitable designs, cold heading can move material into shape without cutting away the main structure. This may support favorable material flow and production efficiency, but it does not replace material, hardness or functional verification.
Machined geometry
Machined strength depends on the remaining section after material removal. Sharp corners, thin walls, insufficient thread engagement or reduced bearing area can create risk if the drawing is not reviewed properly.
Function-specific testing
Depending on the nut, approval may require proof load, torque-out, pull-out, push-out, prevailing torque, weld performance, hardness or thread inspection.
Por exemplo, porcas autotravantes totalmente metálicas may involve prevailing torque requirements when specified, while weld nut projects may need torque-out or pull-out checks depending on the joint and drawing. Test scope must be confirmed by the buyer’s drawing and customer standard.
Tolerance Comparison: Formed Accuracy, Machined Features and Critical Dimensions
Tolerance is feature-specific. It is not correct to say that cold heading or CNC machining is always more accurate for the entire part. Cold heading can be stable for repeatable formed dimensions after tooling is validated. CNC machining can be stronger for tight local features, shoulders, side holes, counterbores, special faces or features that need precise location. Some custom nuts require both.
Cold heading and CNC machining should be compared by critical feature, not by process name alone.
Diagram uses generic callouts only; actual tolerances must follow the buyer’s drawing and inspection requirement.
Formed tolerances are process-capability dependent
Cold heading can produce repeatable dimensions, but capability depends on material, tooling, machine setup, feature geometry and inspection method. The supplier should confirm which features are formed and which features require secondary operations.
Machined features can control local critical dimensions
CNC machining can be useful when a drawing has critical local dimensions that are difficult to form. For example, a special shoulder, pilot diameter, side hole or flat may be machined after forming. This can help balance cost and precision. For basic dimensional language such as thread size, across flats and nut height, buyers can also review the guia de dimensões de porcas sextavadas before preparing an RFQ.
Coating can change thread fit and inspection results
Thread fit must be reviewed after coating. Plating, phosphate, zinc-nickel, black oxide, passivation or other surface treatments can affect thread engagement and torque behavior. If coating is required, the buyer should confirm post-coating thread inspection and any post-plating allowance.
Feature Type
Cold Heading Consideration
CNC Machining Consideration
Typical Decision
External blank shape
Good if formable and repeatable
Possible but may waste material
Cold heading for volume
Across flats / height
Can be stable after tooling validation
Can be machined for special requirements
Depends on tolerance and volume
Tópico
Often needs tapping or rolling
Can be machined or tapped
Confirm thread size, pitch and tolerance
Side hole / slot
May be difficult to form
Often suitable for machining
CNC or secondary machining
Shoulder / pilot
May be formed if geometry allows
Machining may control local precision
Hybrid route often useful
Ajuste de rosca pós-revestimento
Must be inspected after coating
Must be inspected after coating
Process route alone is not enough
Critical-to-Quality Reminder
Buyers should mark which dimensions are critical to function before asking for a process recommendation. A non-critical formed surface and a critical machined shoulder should not be treated the same. The inspection plan should follow the CTQ features, not only the process name.
Volume and Approval Stage: Prototype, Sample, PPAP and Mass Production
The correct route can change by project stage. CNC machining may be the fastest way to make a prototype. Cold heading may be the better route for mass production. But if the part will be used in an automotive application, the sample route and production route must be clearly controlled.
When the custom nut is tied to a functional joint, buyers should also provide assembly location, joint type, mating part condition and expected failure mode. These details can affect proof load, pull-out, torque-out, prevailing torque, weld retention, thread engagement and final inspection scope. Buyers can compare these risks with common problemas de montagem automotiva resolvidos por porcas especiais antes de finalizar o escopo do RFQ.
CNC prototype for design checking
A CNC prototype can help verify design intent, assembly clearance, mating part condition, thread engagement and basic geometry. It is useful before investing in forming tooling. However, a CNC prototype may not represent the final cold-headed production process.
Production-intent samples for approval
If the customer requires production-intent samples, the supplier should use the planned production route or explain any difference clearly. This is especially important for automotive projects, where process route, inspection data and approval documents may need to align. Buyers evaluating automotive projects can also review how porcas especiais personalizadas para OEMs automotivos move from design review to stable mass production.
Why route changes must be confirmed before PPAP
PPAP is required only when the customer or project specifies it. If PPAP applies, the manufacturing route, drawing revision, material, inspection method and production process should be confirmed before submission. A route change after approval may require additional review depending on customer requirements.
Pergunta
Por que é Importante
Was the sample CNC machined but production will be cold headed?
The sample may not represent production-intent characteristics
Will the thread be cut, tapped or rolled in production?
Thread method can affect fit and performance
Will heat treatment be added after sample approval?
Hardness and dimensional behavior may change
Will coating be added after sample approval?
Thread fit and torque behavior may change
Are critical dimensions formed or machined?
Inspection plan must match process route
Is annual volume stable enough for tooling?
Tooling investment depends on demand confidence
Has the production-intent route been frozen?
Approval and mass production should not be based on unclear route assumptions
When a Hybrid Route Makes More Sense
A hybrid route often gives the best balance between cost, function and geometry. Instead of machining the entire nut from bar stock, the supplier may cold head a near-net blank and machine only the critical features. Instead of forcing a complex nut into a difficult forming route, the supplier may use CNC for features that cannot be formed reliably.
Many custom nuts use a hybrid route to balance forming efficiency with machined critical features.
Process steps shown are conditional; actual route depends on drawing, material, function and order requirement.
Cold headed blank plus secondary machining
This route can be useful when the basic nut shape is suitable for forming but one or two features require machining. Examples may include a side slot, pilot diameter, controlled face, special shoulder or feature location.
When tapping or thread rolling changes the route
The thread process must be confirmed. Some nuts may be tapped. Some external threads may be rolled. Some special internal forms may need a specific tooling or inspection plan. The thread size, pitch, tolerance and coating condition should be included in the RFQ.
When coating or heat treatment changes final inspection
Heat treatment and coating can change the final inspection plan. If heat treatment is required, hardness and dimensional stability may need review. If coating is required, post-coating thread fit and surface condition should be inspected.
Hybrid Route Example
Why It May Be Used
Buyer Confirmation Needed
Cold headed blank + tapping
Efficient blank forming with controlled internal thread creation
Thread size, pitch, tolerance and gauge method
Cold headed blank + CNC side feature
Forms the main body while machining a slot, side hole or shoulder
Feature location, burr control and inspection method
CNC prototype + cold heading production
Supports early design review before tooling investment
Whether production-intent samples are required later
Forming + heat treatment + coating
Used when material strength or surface protection is specified
Hardness, coating, post-coating thread fit and inspection scope
Common RFQ Mistakes When Comparing Cold Heading and CNC Machining
Many quote problems start because the buyer and supplier are comparing different assumptions. A supplier quoting CNC prototypes may look expensive for mass production. A supplier quoting cold heading may look expensive for a first batch because tooling is included. A supplier quoting a simplified route may miss secondary operations.
Comparing different route assumptions
A CNC sample quote and a cold heading production quote answer different questions. Buyers should ask for the route behind the price.
Ignoring secondary operations
A quote that says “cold headed” may still require tapping, thread rolling, machining, heat treatment, coating, sorting and packing.
Forgetting coating and thread fit
If the RFQ does not state coating and thread tolerance, the quoted route may look correct before coating but create problems after plating or surface treatment.
Practical buyer check: ask the supplier to separate prototype route, sample route and mass-production route in the quotation. This prevents comparing a CNC development quote with a cold heading production quote as if they were the same scope.
RFQ Checklist: Data Needed Before SUNHYINGS Can Recommend a Process Route
Before choosing cold heading, CNC machining or a hybrid route, the supplier needs enough data to understand the part function and production goal. A drawing is the best starting point. If no drawing exists, a sample photo, rough dimensions and application description can help start the review, but final quotation still needs confirmed technical data.
A useful RFQ should define drawing, thread, material, tolerance, volume, coating, function and approval requirements.
Checklist graphic for buyer preparation; it does not represent a universal approval or document guarantee.
Drawing and geometry data
Send the drawing revision, part number, overall dimensions, thread size, pitch, tolerance, across flats, height, flange diameter, shoulder dimensions, side features, holes, slots, bearing surfaces and any critical dimensions. If the part is made-to-print, the latest drawing revision should control the review.
Volume, assembly and approval data
Send sample quantity, first batch quantity, annual volume forecast and expected production life. Also state whether the project is for prototype, trial build, PPAP, mass production, replacement part or cost reduction. If the nut function is tied to a welded joint, clinched joint, locking feature, bracket, sheet-metal assembly or load-bearing thread, provide assembly location, joint type, mating part material or thickness, and the failure mode that must be avoided.
Material, coating and testing data
Send material grade, hardness or property class, heat treatment requirement, coating requirement, post-coating thread fit expectation, corrosion requirement if specified, and functional test requirements such as proof load, torque-out, pull-out, push-out or prevailing torque when applicable.
The supplier may quote a part shape without understanding the functional failure mode
Requisito de tratamento térmico
Affects hardness, distortion and approval
Sample and production behavior may differ
Requisito de revestimento
Affects thread fit and corrosion expectation
Post-coating inspection scope may be missed
Volume anual
Determines whether tooling is justified
Supplier may quote the wrong route
Quantidade de amostra
Helps choose prototype route
Development cost may be compared incorrectly
Requisito funcional
Defines proof load, torque-out, pull-out, prevailing torque or other tests
Strength and performance risk remain undefined
Approval requirement
Clarifies PPAP, IMDS, dimensional report or customer documents if required
Production route may not match approval needs
How SUNHYINGS Reviews Cold Heading vs CNC Machining for Custom Nuts
SUNHYINGS should review cold heading, CNC machining and hybrid route options from the drawing and application first, not from process preference. The best route is the one that matches the nut geometry, material, tolerance, function, volume and approval requirement.
Drawing-first process review
The review starts with the drawing, sample or application description. Key points include thread size, pitch, tolerance, external geometry, flange or shoulder shape, side features, wall thickness, bearing face, coating and heat treatment. If information is missing, the correct answer is “needs confirmation,” not an assumption.
Cost and volume route comparison
For low quantity or changing designs, CNC machining may be the practical first route. For stable medium or high volume, cold heading or a cold-headed blank plus secondary machining may reduce unit cost. The final decision depends on tooling cost, material, feature complexity and annual demand.
Sample and production route confirmation
If the buyer starts with CNC samples but expects cold-headed mass production later, the route change should be reviewed before approval. For automotive projects, the sample route, production route, inspection plan and approval documents should be aligned with customer requirements.
Request a Manufacturing Route Review for Your Custom Nut
For a custom nut project, prepare your drawing or sample photo, thread size, material, tolerance, coating, annual volume, sample quantity, critical features, assembly location, joint type, functional testing needs and approval requirements. SUNHYINGS can review whether cold heading, CNC machining or a hybrid route is more suitable before quotation or sampling.
Recommended Input
Por que é Importante
Drawing or sample photo
Confirms geometry, features and formability
Tamanho da rosca, passo e tolerância
Controls tapping, rolling, machining and inspection
Material and hardness/property class
Controls formability, machinability and functional strength
Coating and post-coating thread fit
Controls final thread inspection and assembly risk
Clarifies proof load, torque-out, pull-out, push-out or prevailing torque if required
Approval documents if required
Clarifies PPAP, IMDS, dimensional report or customer-specific document scope
Technical References and Standards Context
Use these references for context only. The buyer’s latest drawing revision, customer-specific requirement and purchase agreement remain the controlling documents for actual process approval, testing and submission scope.
IMDS Public Pages — automotive material data system context when material reporting is required by the customer or program.
PERGUNTAS FREQUENTES
A conformação a frio é sempre mais barata que a usinagem CNC para porcas personalizadas?
Não. A estampagem a frio pode reduzir o custo unitário quando a geometria é adequada e o volume justifica a ferramentaria. A usinagem CNC pode ser mais barata para protótipos, pedidos de baixo volume ou projetos que ainda estão em alteração. A comparação correta deve incluir custo de ferramentaria, custo unitário, aproveitamento de material, operações secundárias e volume anual.
Porcas laminadas a frio são mais resistentes do que porcas usinadas em CNC?
Não automaticamente. A recalcagem a frio pode favorecer o fluxo de material quando o material e a geometria são adequados, mas a resistência final depende do material, geometria, tratamento térmico, engate da rosca, revestimento e ensaio funcional. Uma porca usinada em CNC pode ser adequada quando o projeto e o material atendem ao requisito.
Quando devo escolher a usinagem CNC para uma porca personalizada?
Escolha a usinagem CNC quando o pedido for de baixo volume, o design ainda estiver mudando, a peça tiver características complexas ou for necessário um protótipo antes do investimento em ferramentas. A CNC também é útil para usinagem secundária após o encabeçamento a frio.
Um protótipo CNC pode ser aprovado para produção em massa por recalcamento a frio?
Não automaticamente. Um protótipo CNC pode ser útil para verificação do design, mas pode não representar a rota de produção final por encruamento a frio. Se a aprovação depender do processo de produção, o comprador deve confirmar se amostras representativas da produção são necessárias.
Uma porca personalizada pode usar tanto o forjamento a frio quanto a usinagem CNC?
Sim. Muitas porcas personalizadas usam um processo híbrido. O blank pode ser forjado a frio para eficiência de volume, enquanto recursos especiais, como ranhuras, ressaltos, furos laterais ou faces de apoio, podem ser usinados posteriormente.
Qual processo oferece melhor tolerância para porcas personalizadas?
Depende da característica. O encabeçamento a frio pode ser estável para dimensões formadas após a validação da ferramenta. A usinagem CNC pode ser melhor para características locais apertadas. Revestimento, tratamento térmico e inspeção de rosca também podem afetar a tolerância final e o ajuste.
O que devo enviar para um orçamento de conformação a frio vs usinagem CNC?
Send the drawing or sample photo, drawing revision, material, thread size and tolerance, critical dimensions, coating requirement, heat treatment requirement, assembly location, joint type, sample quantity, annual volume, functional testing needs and approval documents if required.
Technical Review Note
This article was prepared for sourcing managers, purchasing engineers, SQE teams, mechanical engineers and fastener engineers comparing cold heading, CNC machining and hybrid process routes for custom nuts. Final process selection must be confirmed against the latest drawing revision, material, geometry, thread requirement, coating, assembly condition, annual volume, customer approval requirement and purchase agreement.
Reviewed scope: custom nut manufacturing route selection, tooling cost, unit cost, volume, material utilization, strength boundaries, feature-specific tolerance, sample route risk, hybrid routing, assembly/joint input requirements and RFQ preparation.
Related SUNHYINGS Pages
Review related SUNHYINGS pages for custom nut types, assembly function and dimensional preparation before sending an RFQ.
Standards and limitation note: This article is a practical sourcing and engineering guide. It does not replace the customer drawing, customer-specific requirement, formal PPAP submission, IMDS reporting requirement, qualified engineering review or supplier process approval. Final requirements for material, hardness, coating, tolerance, process route, inspection, functional testing, traceability and record retention must be confirmed by the drawing revision, customer standard and purchase agreement.
