How much does it cost · stainless passivation
Passivation costs little per part, but the subcontractor charges a minimum per lot, typically €50 to €120 according to QuoteBuddy (source: QuoteBuddy, August 2026). The bath lasts at least 30 minutes in nitric acid at room temperature under ASTM A967 (Nitric 2 treatment), and 4 to 30 minutes in citric acid under AMS 2700, the hotter the bath, the shorter (source: Advanced Plating Technologies, January 2026). RFQdecoder counts this time per load, divides it by the number of parts in the load, and raises any lower amount to €50 on a dedicated quote line.
According to QuoteBuddy, passivation is priced by the batch, not by cycle time, like every outsourced finish (source: QuoteBuddy, August 2026). The lot minimum dominates almost every passivation line because the processing cost per part is tiny; typical minimums run from €50 to €120 per lot (source: QuoteBuddy, August 2026).
QuoteBuddy works through an example with a €90 lot minimum and a 15% handling markup on the outside service, i.e. €103.50 per lot. Per part, that gives (source: QuoteBuddy, August 2026):
On the chemistry, QuoteBuddy rates citric acid as “comparable; often slightly higher per lot”, with nitric acid as the baseline (source: QuoteBuddy, August 2026). Certification adds a per-lot charge and sometimes a day (source: QuoteBuddy, August 2026).
A published reference from a US job shop: Santa Clara Plating lists a minimum charge of $70 for passivating 300-series stainless (other than 303), 13-8, 15-5 and 17-4 stainless, Nitronic 60 or titanium, $85 for 303 and $150 for any 400-series stainless (source: Santa Clara Plating, December 2022).
ASTM A967 covers several types of chemical passivation treatments for stainless steel parts; it also gives recommendations for descaling and cleaning, and several alternative tests to confirm that the treatment worked (source: ASTM International, January 2025).
For nitric acid, the ASTM A967 Nitric 2 treatment uses 20 to 45% nitric acid by volume, at 70 to 90 °F (about 21 to 32 °C), for 30 minutes minimum (source: Advanced Plating Technologies, January 2026); Gleco Plating gives the same values in its table of nitric treatments (source: Gleco Plating, August 2026).
For citric acid, AMS 2700 Method 2 sets a bath temperature of 70 to 160 °F (21 to 71 °C) and a minimum immersion time that depends on that temperature (source: Advanced Plating Technologies, January 2026):
Gleco Plating sums it up: AMS 2700 defines a single citric method, run anywhere from 70 to 160 °F for 4 to 30 minutes (source: Gleco Plating, August 2026). In Products Finishing magazine, David S. Peterson puts a passivation run at a minimum of 20 minutes per batch, with the operator free to do other tasks between loads (source: Products Finishing, October 2014).
The parts soak together, load by load, in an acid bath that rebuilds the passive layer. The tool uses the published bath time:
When the drawing does not specify the method, the tool uses nitric acid and the quote says so. This is a common case: Advanced Plating Technologies notes that very few part prints indicate the specific passivation method to be employed (source: Advanced Plating Technologies, January 2026). QuoteBuddy adds that if the print just says “passivate”, either method is usually acceptable (source: QuoteBuddy, August 2026).
Bath time is a load time: the tool divides it by the number of parts in the load, which is a required input. Loading (5 minutes) and inspection (3 minutes) are added per load. These two durations and the station rates are tool values, not sourced.
Since 4 October 2026, the tool applies the minimum published by QuoteBuddy, €50 to €120 per lot (source: QuoteBuddy, August 2026): below that amount, the price is raised to the bottom of the range, €50, and the quote shows it on a “subcontractor minimum order” line.
Assumptions (chosen for illustration, not taken from a source): machined bushing in 316L stainless; the drawing says “passivate” without naming the method; one hourly rate of €60/h for the bath, loading and inspection, i.e. €1 per minute; two orders, 20 parts in one load of 20, then 500 parts in five loads of 100.
Values used: 30-minute nitric bath (source: Advanced Plating Technologies, January 2026); minimum of €50 to €120 per lot, raised to €50 (source: QuoteBuddy, August 2026); loading 5 minutes and inspection 3 minutes per load (tool values, not sourced).
For comparison, QuoteBuddy’s example, a €90 minimum plus 15%, gives €2.07 per part for 50 parts and €0.52 for 200 (source: QuoteBuddy, August 2026).
The RFQdecoder quote says so: two operations are not included.
If the specification calls for them, these items come on top of the calculated price.
The subcontractor mainly charges a minimum per lot, typically €50 to €120 according to QuoteBuddy. The price per part therefore depends on quantity: in QuoteBuddy’s example (a €90 minimum plus 15%), €103.50 for a single part, €2.07 each for 50 parts and €0.52 each for 200.
QuoteBuddy describes citric acid as comparable, often slightly higher per lot than nitric acid, and says the cost gap between them is rarely what decides the quote: the lot minimum is. The citric bath can be shorter (4 minutes above 60 °C under AMS 2700) than the Nitric 2 bath (30 minutes).
In nitric acid under ASTM A967 (Nitric 2), 30 minutes minimum at 70 to 90 °F, about 21 to 32 °C. In citric acid under AMS 2700, from 4 minutes above 140 °F (60 °C) to 30 minutes below 100 °F (38 °C). The parts soak together, so the time is shared among the parts in the load.
Because the calculated price is below the minimum subcontractors charge, €50 to €120 per lot according to QuoteBuddy. Since 4 October 2026, RFQdecoder then raises the price to €50, the bottom of the range, and shows it on that line.
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