What Happens Between Your RFQ and Your First Part: The Machining Process Explained
Most buyers interact with a machine shop at two points: when they submit a request for quote, and when parts arrive. What happens in between is largely invisible — and that opacity creates unrealistic expectations about lead times, cost drivers, and why certain decisions get made during production.
Understanding the process that converts your drawing into a finished part helps you write better RFQs, set realistic schedules, and have more productive conversations with your supplier when questions arise. FM Machine’s precision CNC machining process follows a consistent sequence from inquiry to delivery.
Step 1: RFQ Review and Quoting
When an RFQ arrives, the shop reviews your drawings before generating a number. A complete, dimensioned drawing with tolerances, material specification, and delivery requirement allows the shop to estimate setup time, run time, material cost, tooling requirements, and inspection time accurately.
During this review, DFM concerns are identified — features that will drive cost or risk that could be addressed with minor design changes. A shop that flags these issues before quoting is protecting your budget. A shop that quotes without reviewing and raises problems after the PO is placed is creating friction.
The output of this step is a quote with a price and lead time. For simple parts from a regular customer with materials in stock, this can happen in hours. For complex parts with exotic materials or tight tolerance requirements, it may take a day or two.
Step 2: Purchase Order and Job Release
When you issue a purchase order, the job enters the shop’s scheduling system. Scheduling accounts for current machine utilization, material availability, and delivery commitment. A job can’t start before materials arrive — and material lead time is often the first critical path item.
This is the step where jobs wait if the shop is loaded. A shop with transparent scheduling will tell you where your job sits in the queue and when it’s expected to start. If your delivery date is tight, raising that during the quoting conversation — rather than after PO issuance — allows the shop to tell you whether it’s achievable before you commit.
Step 3: Material Procurement and Receiving
Unless the shop maintains stock inventory of your specified material, material is ordered after PO receipt. Common materials — 6061 aluminum, 303/316 stainless, 4140 steel — typically arrive within a day or two from local distributors. Specialty alloys, certification-required materials, or unusual sizes may take longer.
Material is inspected at receiving for correct alloy, size, and certification. If material certifications (MTRs) are required by your drawing or purchase order, they are reviewed and retained at this step. This is the foundation of the traceability chain that supports your quality documentation.
Step 4: Programming and Setup Planning
For new part numbers, a CNC programmer reviews the drawing and creates the machining program using CAM software. The programmer determines the machining sequence, tooling selection, cutting parameters, and workholding approach. For complex parts requiring multiple setups or multi-axis operations, this planning step is where most of the intellectual work of machining happens.
The quality of the program directly affects dimensional accuracy, surface finish, and cycle efficiency. A well-planned program machines the part correctly on the first attempt. A poorly planned program generates scrap, requires program edits mid-run, and produces inconsistent results.
For repeat part numbers, existing programs are retrieved and verified — if fixturing and tooling are unchanged, the setup is straightforward. This is why repeat orders typically have shorter lead times than new part introductions.
Step 5: Fixturing and Setup
The physical setup involves installing tooling in the machine, building or retrieving the workholding fixture, loading the program, and indicating the part to confirm it’s correctly located in the machine coordinate system. For precision machined parts, setup time is often the largest single cost component on low-volume work.
A first piece is cut and measured before production quantities proceed. This is where programming errors, tooling issues, and fixture problems are identified and corrected. The time invested here is what prevents dimensional problems from propagating through the entire run.
Step 6: Production Machining
With a proven setup, production machining proceeds. In-process gauging verifies critical dimensions periodically during the run. Tool wear is monitored and tools are changed before they degrade enough to affect dimensional accuracy. For tight-tolerance work, temperature and thermal expansion are managed through shop environment controls and machining practice.
FM Machine’s inspection capabilities include in-process CMM measurement for parts where dimensional verification between operations is required.
Step 7: Deburring and Secondary Operations
Most machined parts require deburring after machining — removing sharp edges, burrs from drilled holes, and tool marks from feature intersections. Secondary operations specified on the drawing — heat treatment, anodize, plating, passivation, grinding — are performed or subcontracted at this stage.
Secondary operations that require outside processing add lead time proportional to the turnaround time of the subcontractor. This is why secondary operation requirements communicated at the RFQ stage produce better outcomes than those raised after the job starts.
Step 8: Final Inspection and Documentation
Before parts ship, final inspection verifies that all dimensions, surface finishes, and special requirements conform to the drawing. Inspection results are documented — from a simple certificate of conformance for standard commercial work to a full CMM dimensional report for aerospace or medical applications.
Documentation is assembled into a package that ships with the parts: certificate of conformance, material certifications, inspection report, special process certs, and any customer-specific quality documentation required by the purchase order.
Step 9: Packaging and Shipment
Parts are packaged to protect finished surfaces, coatings, and precision dimensions during transit. Special packaging requirements — part-by-part protection, cleanroom bagging, specific labeling — should be specified in the purchase order. Parts ship with documentation attached to confirm the shipment is complete.
Start the Process With a Complete RFQ
Every step in this process moves faster when it starts with complete, accurate information. A drawing without tolerances, a purchase order without a delivery date, or a material specification that requires interpretation all create friction that extends lead time and introduces risk.
Submit your RFQ to FM Machine with your drawings and requirements — we’ll take it from there and keep you informed at every step.