Material and Buy-to-Fly
Start with the raw stock required: bar length or plate size to fit the part plus cutoff, clamping allowance and kerf. Aerospace parts often cut 70 to 90 percent of the stock to chips, especially thin-walled housings and brackets from plate, so material cost per finished part is far above part weight times price. Add the premium for certified material (mill cert, domestic melt, AMS spec), minimum order quantities, and cut or saw charges.
For titanium and nickel alloys, price swings and long lead times make quote validity short. Scrap allowance for first parts and a small lot of two or three extra pieces to cover FAI and nonconformance should be explicit in the estimate, not hidden.
Setup, Cycle Time and Programming
Break the routing into operations and estimate each: programming and proving the first article, fixture design or setup, run time per piece, and in-process inspection.
- Setup hours per operation, divided across lot size, which dominates cost on lots of 1 to 25
- Cycle time per op from CAM simulation or from similar past parts, adjusted for material removal rate in the alloy
- Tool life and change time for hard materials; tooling cost per part for custom form tools
- Deburr, break edge and cleaning, which are often 10 to 25 percent of labor on complex parts
- Programming and first-piece proof time, charged once as non-recurring
Special Processes, Inspection and Documentation
Add outside processing at vendor price with minimum lot charges, which often exceed per-part cost on small lots, plus freight and the lead time cost. Include inspection time against the control plan: in-process checks, final inspection, CMM time, and FAI per AS9102 when required. Add documentation labor for the C of C, cert packet and any customer portal uploads.
Quality surcharges for source inspection or witness points should be explicit. Many aerospace parts also need serialization or laser marking. Missing any of these is how a 20 percent margin quote turns into a loss, especially on the first small lot.
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Subcontract and Outside Processing Cost Worksheet
Cost each outside operation with price per piece, vendor minimum charge and freight, and see the true cost per part.
Overhead, Risk and Margin
Apply a shop rate by work center that reflects true cost per hour, including machine depreciation, tooling consumables, programming and indirect labor, rather than one blended rate. Then add a risk allowance for unknowns: new alloy, tight tolerance features, thin walls prone to distortion, first-time customer, or heavy rework history on similar parts. Finally add margin.
Keep the structure consistent so quote-to-actual comparison identifies where you are wrong. Without a closed loop from completed jobs back to estimating, errors repeat on every bid.
Using AI Without Inventing Numbers
A private model grounded in your ERP can read the drawing, identify material, features and special processes, retrieve the closest past jobs with actual hours and costs, and draft the buildup with every figure linked to a source job. The estimator edits and approves. It cannot guess a cycle time for a part type you have never made, and it should say so.
Where you quote few parts, or each is unique, a seasoned estimator with CAM simulation remains faster. AI helps most with repeat families and volume of RFQs.
Frequently asked questions
How do you estimate machining time for a new part?
Use CAM simulation if available, or compare to similar parts you have made, scaling by material removal volume and feature count. Add setup and programming separately. Validate against actuals after the first lot and update your standards, since estimates drift when never checked.
Why are aerospace parts more expensive than commercial parts?
Certified material, hard alloys with slow cycle times, tight tolerances, special process vendors, FAI and documentation, and quality requirements such as source inspection all add cost. Lot sizes are also small, so setup and non-recurring costs spread over fewer parts.
What markup should a machine shop use on aerospace work?
There is no universal figure. Set margin from your shop rate, your risk on the job and the market for that part type. Track quoted versus actual margin by customer and part family, and adjust where you consistently lose or overcharge.
Have Netray draft grounded cost buildups from your own past jobs on-prem, so estimators spend time on judgment instead of searching old routers.