- Key Takeaways
- What Drives CNC Machining Cost?
- How Does Quantity Change the Price per Part?
- Is Aluminum Cheaper to Machine Than Stainless Steel?
- How Much Do Tighter Tolerances Add?
- What Does Surface Roughness Cost?
- How Much Do Surface Finishes Add?
- What Is the Hourly Rate for CNC Machining?
- How to Reduce CNC Turning Costs
- FAQ
There's no single price: CNC machining cost depends on the part's size, features, material and, above all, quantity. To measure how much each factor moves the price, we quoted two CNC turned parts, one Ø25 mm and one Ø55 mm, on Komacut's instant quote platform in September 2026, in aluminum 6061, stainless steel 304 and carbon steel Q235. They cost $29.50–42.93 as single pieces and $2.77–12.56 each at 1,000 pieces. Quantity moved the price more than anything else. Material came second, and it mattered more at volume than for prototypes.
Key Takeaways
Quantity is the biggest lever: unit price fell 71–91% from 1 to 1,000 pcs.
Order 3–5 prototypes instead of 1. Three simple aluminum parts cost $36.72 in total, $7.22 more than one.
Savings flatten past 1,000 pcs: 100,000 pcs was only 7.6–8.3% cheaper per part.
SS304 costs 8–19% more than 6061 aluminum at 1 pc, but 42–53% more at 1,000 pcs.
Finishes add 1–22% per part at 1,000 pcs. At 1 pc, going from coarse to fine tolerance adds 4–5%, and from standard to high-grade roughness 8–10%.
Table of Contents
- Key Takeaways
- What Drives CNC Machining Cost?
- How Does Quantity Change the Price per Part?
- Is Aluminum Cheaper to Machine Than Stainless Steel?
- How Much Do Tighter Tolerances Add?
- What Does Surface Roughness Cost?
- How Much Do Surface Finishes Add?
- What Is the Hourly Rate for CNC Machining?
- How to Reduce CNC Turning Costs
- Frequently Asked Questions
What Drives CNC Machining Cost?
Ranked by how much each factor moved the price in our quotes:
- Quantity: 71–91% cheaper per part at 1,000 pcs than at 1 pc
- Part size and features: the larger, more complex part costs about three times the simple one at 1,000 pcs, but only 19–35% more at 1 pc
- Material: SS304 costs 42–53% more than 6061 aluminum at 1,000 pcs
- Surface finish: +1% to +22% at 1,000 pcs
- Surface roughness: +8–10% from standard (Ra 3.2) to high grade (Ra 0.8), single-piece quotes
- General tolerance class: +4–5% from ISO 2768-c to 2768-f, single-piece quotes
All prices are USD per unit, quoted on the Komacut platform in September 2026 from the China facility. Unless a table says otherwise, parts are quoted at ISO 2768-m, standard roughness (≤3.2 µm Ra), no finish on aluminum and stainless, and antirust oiling on carbon steel.
| Part | Outer diameter | Features (as detected by the platform) |
|---|---|---|
| A: Simple | 25 mm | 1 hole, 2 fillets |
| B: Complex | 55 mm | 3 holes, 2 chamfers, 1 counterbore, 7 countersinks |
How Does Quantity Change the Price per Part?
The first part you order carries almost the whole setup: programming, tool setting and first-part inspection. The 1,000th part carries almost none of it.
| Part | Material | 1 pc | 10 pcs | 100 pcs | 1,000 pcs | Saving, 1 → 1,000 |
|---|---|---|---|---|---|---|
| A: Simple | Aluminum 6061 | $29.50 | $5.99 | $3.25 | $2.77 | −91% |
| A: Simple | Stainless SS304 | $31.77 | $7.54 | $4.53 | $3.93 | −88% |
| A: Simple | Carbon steel Q235 | $33.57 | $6.53 | $3.44 | $2.91 | −91% |
| B: Complex | Aluminum 6061 | $35.97 | $12.86 | $9.23 | $8.21 | −77% |
| B: Complex | Stainless SS304 | $42.93 | $18.52 | $14.02 | $12.56 | −71% |
| B: Complex | Carbon steel Q235 | $39.95 | $13.39 | $9.41 | $8.35 | −79% |
Part B saves the least. Its countersinks, counterbore and chamfers take machine time on every piece, and run time doesn't spread across a batch the way setup does.
The price-break curves also show how much of the price is setup. The 100,000-pc price is close to pure run cost. Subtract it from the 1-pc price and what's left is the fixed cost of the order. That comes to $27–32 for every part and material we quoted. Part A in aluminum runs at $2.54 a piece and part B at $7.57. Setup costs about the same whichever part you order. What multiplies the running cost is part B's larger diameter and extra features.
Order 3–5 prototypes, not 1
The steepest drop comes before 10 pieces. Part A in aluminum costs $29.50 for one, $12.24 each for three and $8.74 each for five. Three pieces cost $36.72 in total, only $7.22 more than one. If you'll need a spare, a test sample or a second fit check, order it in the first batch.
Savings flatten after 1,000 pcs
Going from 1,000 to 100,000 pcs cut the unit price by only 7.6–8.3% across all six part and material combinations. Part A in aluminum drops from $2.77 to $2.54. Past 1,000 pieces, the only way to cut cost further is to change the part: less material removed, fewer features, a cheaper alloy.
Is Aluminum Cheaper to Machine Than Stainless Steel?
Yes, and the gap grows with quantity. At 1 piece, SS304 costs 8–19% more than 6061 aluminum, because setup makes up most of the price whatever the material. At 1,000 pieces the premium is 42–53%.
Stainless costs the most on part B, which has more features to cut. A 2026 study of stainless steel turning in Machines attributes stainless steel's poor machinability to low thermal conductivity (about 16 W/m·K), a high work-hardening tendency and strong adhesion to cutting tools. Each extra feature cut in stainless costs more than the same feature in aluminum.
For prototypes, pick the material the part needs; the price difference is small. For production, question every stainless spec. If the part only needs corrosion protection, anodized 6061 costs less. Carbon steel Q235 isn't a shortcut on these parts: it cost 11–14% more than aluminum at 1 piece and 2–5% more at 1,000. Our metal selection guide for CNC machining covers the property trade-offs.
How Much Do Tighter Tolerances Add?
Very little within the general tolerance classes. ISO 2768-1 sets general tolerances for dimensions without an individual tolerance on the drawing. For a 6–30 mm dimension, that's ±0.1 mm in the fine class, ±0.2 mm in medium and ±0.5 mm in coarse.
Single-piece quotes, part B:
| Material | Coarse (2768-c) | Medium (2768-m) | Fine (2768-f) | Fine vs coarse |
|---|---|---|---|---|
| Aluminum 6061 | $34.69 | $35.97 | $36.34 | +4.8% |
| Carbon steel Q235 | $38.71 | $39.95 | $40.48 | +4.6% |
| Stainless SS304 | $41.61 | $42.93 | $43.59 | +4.8% |
Part A shows the same pattern: +3.9% to +4.3% from coarse to fine. Loosening the general tolerance class won't save much, so choose it for function, not price. Komacut's process tolerances page lists the full ISO 2768 tables for CNC turning.
What Does Surface Roughness Cost?
Komacut quotes four roughness grades for CNC turning, from as-milled (≤6.0 µm Ra) to high grade (≤0.8 µm Ra). Single-piece prices:
| Part | Material | As milled ≤6.0 Ra | Standard ≤3.2 Ra | Fine ≤1.6 Ra | High grade ≤0.8 Ra |
|---|---|---|---|---|---|
| A: Simple | Aluminum 6061 | $28.65 | $29.50 | $30.36 | $31.95 |
| A: Simple | Stainless SS304 | $30.85 | $31.77 | $32.69 | $34.41 |
| B: Complex | Aluminum 6061 | $34.69 | $35.97 | $37.07 | $39.27 |
| B: Complex | Stainless SS304 | $41.61 | $42.93 | $44.47 | $47.33 |
| B: Complex | Carbon steel Q235 | $38.71 | $39.95 | $41.36 | $44.02 |
Going from standard to high grade adds 8–10%, about twice the cost of going from coarse to fine tolerance. Call out fine or high-grade roughness only on the surfaces that need it. Our guide to CNC machining surface roughness covers which Ra value suits which function.
How Much Do Surface Finishes Add?
At 1 piece, no finish moved the price by more than 5% either way. At 1,000 pieces they add 1–22%, because the finish is paid on every part while setup is spread across the batch. Added cost at 1,000 pcs, compared with the unfinished part (antirust oiling for carbon steel):
| Material | Finish | A: Simple (Ø25 mm) | B: Complex (Ø55 mm) |
|---|---|---|---|
| Aluminum 6061 | Anodize, black | +$0.38 (+13.7%) | +$0.61 (+7.4%) |
| Aluminum 6061 | Powder coat, Black Sandtex | +$0.50 (+18.1%) | +$0.77 (+9.4%) |
| Stainless SS304 | Passivation | +$0.42 (+10.7%) | +$0.89 (+7.1%) |
| Stainless SS304 | Powder coat, Black Sandtex | +$0.53 (+13.5%) | +$1.04 (+8.3%) |
| Carbon steel Q235 | E-coating | +$0.06 (+2.1%) | +$0.11 (+1.3%) |
| Carbon steel Q235 | Zinc plating, trivalent | +$0.25 (+8.6%) | +$1.08 (+12.9%) |
| Carbon steel Q235 | Powder coat, Black Sandtex | +$0.65 (+22.3%) | +$1.04 (+12.5%) |
The larger part pays more in dollars but a smaller percentage, because its base price is three times higher. Budget finishes in dollars per part. Powder coat cost the most on every material. On carbon steel, e-coating added 6–11 cents a part, the cheapest corrosion protection we quoted.
For how each finish performs in service, see CNC machined parts surface finishing.
What Is the Hourly Rate for CNC Machining?
Shop hourly rates bundle the machine, tooling, overhead and margin with the operator's wage. Wages are the only part with a public benchmark: the U.S. Bureau of Labor Statistics puts median pay for machinists and tool and die makers at $28.66 an hour (2025).
An hourly rate isn't a part price. You also need cycle time, setup hours and batch size. A per-part quote from your CAD file already includes all three, split by quantity.
How to Reduce CNC Turning Costs
Order the right quantity. Order 3–5 prototypes instead of 1, and combine repeat orders into one batch. For part A in aluminum, 100 parts in one order cost $325. Ten orders of 10 cost $599.
Remove features that don't do anything. Every chamfer, countersink and cross-hole adds cycle time to every part.
Design within the process limits. Komacut's DFM rules for CNC turning:
- Part diameter 7–295 mm, length 10–565 mm
- Minimum wall thickness 2 mm
- Minimum hole diameter and minimum thread size 3 mm
- Maximum hole depth 80 mm, or a through-hole
- Hole-to-edge and hole-to-hole spacing at least 2 mm
- Milled features no larger than 50% of the raw stock
- Countersinks at 30°, 45° or 60°
Leave roughness at standard. Ra 3.2 on the whole part, finer grades only where the drawing needs them.
Question stainless steel at volume. A 42–53% premium on 1,000 parts adds up fast.
Pick the finish in dollars. On part A in carbon steel, e-coating costs cents and powder coat costs more than half a dollar.
Our CNC machining drawing guidelines cover how to call out tolerances and finishes so the quote matches what you meant.
Instant Pricing
Get a price for your own part
Upload a STEP file and compare 6061, SS304 and Q235 at every quantity break in about 30 seconds, with DFM feedback on the same screen.
Frequently Asked Questions
How do I estimate CNC machining cost?
Upload your CAD file to an instant quoting platform for a per-part price at each quantity break. To estimate by hand, add a fixed setup cost per order (about $27–32 in our 2026 quotes) to run cost multiplied by quantity. Run cost depends on material, part size, feature count, finish and roughness.
Why is CNC machining so expensive for one part?
A single part carries all of the setup: programming, tool setting, fixturing and first-part inspection. In our quotes that's roughly $27–32 of a $29.50–42.93 single-piece price. Ordering three pieces instead of one cut the unit price by 40–59%, because the same setup was shared across more parts.
How much does CNC machining cost per hour?
There's no single rate: it depends on the machine, the region and the shop's overhead. Operator pay is only part of it. U.S. machinists and tool and die makers earned a median $28.66 an hour in 2025, according to BLS. For budgeting, a per-part quote from your CAD file is more useful than an hourly rate.
Is it cheaper to machine aluminum or stainless steel?
Aluminum is cheaper, and the gap widens with volume. In our quotes, SS304 cost 8–19% more than 6061 aluminum at 1 piece and 42–53% more at 1,000 pieces. Stainless has low thermal conductivity and work-hardens as it's cut, so every extra feature costs more to machine in stainless.
What quantity gives the best price per part?
Most of the saving comes by 100 pieces, and nearly all of it by 1,000. Beyond 1,000, our quotes dropped only another 7.6–8.3% up to 100,000 pieces. For prototypes, 3–5 pieces is the best value: three of a simple aluminum part cost only $7.22 more in total than one.