Aerospace Heat Treating Services to AMS 2750 and Nadcap
Need aerospace heat treating services? We place your parts with heat treaters whose Nadcap AC7102 scope, furnace class and testing fit your AMS 2759, AMS 2770 or AMS 2774 callout, flow down the condition and sequence, and check every cert before shipment. Send the drawing, alloy, final condition, quantity and the operations around heat treat.
Updated
What a buyer needs from an aerospace heat treating service
From a heat treater you need a part in the right final condition, proof that the furnace that ran it was under AMS 2750 control, test results that confirm the condition, and a cert that ties all of it to your lot. Getting that is mostly a matter of choosing a processor whose approvals fit your spec, and giving it a complete order.
Typical requests that reach us: machined 15-5PH or 17-4PH details that need aging to a specific H condition; 4130 or 4340 parts hardened and tempered to a strength range; 7075 or 2024 parts that were formed soft and must be brought to temper; nickel alloy parts that need solution and age; and stress relief between rough and finish machining. Each one is routine for the right shop and a problem for the wrong one.
For the metallurgy behind each alloy family, our heat treatment library page goes deeper. This page is about getting the work placed and documented.
Nadcap heat treat: reading an AC7102 scope
Nadcap heat treating accreditation is audited against AC7102, and the scope certificate shows which parts of it a processor holds. Ask for the current certificate and check the scope against your alloy, process and test method before you place the order.
| Checklist | Title as shown on accredited processors' scopes | Why a buyer cares |
|---|---|---|
| AC7102 | Nadcap Audit Criteria for Heat Treating Baseline | Core audit; the baseline requires AC7102/S and AC7102/8 to be selected with it |
| AC7102/S | Nadcap Supplemental Audit Criteria for Heat Treating | Carries additional subscriber requirements |
| AC7102/5 | Heat Treating, Hardness and/or Conductivity Testing | Tells you whether the processor's own hardness and conductivity tests were audited, and by which methods (for example Rockwell, Vickers, conductivity) |
| AC7102/8 | Heat Treating Pyrometry | Covers the pyrometry system the furnaces run under, with AMS 2750 among the industry spec options |
Scopes also list the industry and customer specifications the processor was audited to, such as AMS 2750, AMS 2759 or AMS 2770. If your spec is not on the list, ask why before you send parts. Revisions of these checklists change and different sites hold different revisions, so read the current certificate in PRI's Qualified Manufacturers List, not an old copy.
Nadcap is required when your contract, prime or drawing requires it. Many primes also keep their own heat treat approval lists by spec. Read your quality clauses and confirm the processor is approved for the exact spec on the date your parts run. For processors, our Nadcap accreditation page explains the program from the supplier side.
Have a part like this?Send it in under a minute. A person replies within 1 business day.AMS 2750H pyrometry, furnace class and instrumentation type in plain terms
AMS 2750 is the pyrometry spec that the heat treat specs invoke. The current revision is AMS 2750H, dated July 2024, which followed revision G of June 2022. Your drawing usually does not cite it directly; the heat treat spec pulls it in. Still, check which revision your prime flows down, because the processor is audited to a specific one.
Two terms decide whether a furnace can run your parts:
- Furnace class is how evenly the furnace holds temperature across its qualified work zone, proven by a temperature uniformity survey (TUS). AMS 2750 has six classes, and a lower class number means a tighter allowed spread. Your heat treat spec sets the tolerance it needs, and the furnace class must be at least that tight.
- Instrumentation type describes how many sensors the furnace has for control, recording and load monitoring, on a scale of types A to E. More sensors give more evidence of what the parts saw. Class and type together set how often the processor must repeat its surveys and system accuracy tests.
What to ask the processor, in plain words:
- Which furnace will run my parts, and what class and instrumentation type is it qualified to?
- Does its current TUS cover the temperature and the work zone my load will occupy?
- When were its last TUS and system accuracy test, and is either due before my parts run?
- Will the cert name the furnace and reference the cycle record?
A processor that answers these quickly is usually running a controlled system. One that only says "we're AMS 2750 compliant" has not answered the question.
AMS 2759, AMS 2770 and AMS 2774: matching the spec to the alloy
Each alloy family has its own process spec, and the processor must be approved for the one on your drawing. Use this table to sort a mixed order before it goes out, then confirm the current revision on SAE.
| Spec | Covers | Typical parts |
|---|---|---|
| AMS 2759 | General requirements for heat treatment of steel parts; the parent document for the slash sheets | Invoked with a slash sheet |
| AMS 2759/1 | Carbon and low alloy steel parts, minimum tensile strength below 220 ksi (1517 MPa) | 4130 and 4340 fittings, brackets, shafts |
| AMS 2759/3 | Precipitation hardening, maraging and secondary hardening steel parts | 15-5PH and 17-4PH details aged to an H condition |
| AMS 2759/4 and /5 | Austenitic and martensitic corrosion resistant steel parts | Annealed 300 series parts; hardened 400 series parts |
| AMS 2759/7 | Carburizing and heat treatment of carburizing grade steel parts (gas, vacuum, liquid and low pressure; revision F, 2026, excludes pack carburizing) | Gears and wear surfaces |
| AMS 2759/9 | Hydrogen embrittlement relief baking of steel parts | High strength steel after plating or certain chemical processes |
| AMS 2759/11 | Stress relief of steel parts | Between roughing and finishing, or after welding |
| AMS 2770 | Heat treatment of wrought aluminum alloy parts | 2024, 6061, 7050 and 7075 machined and formed parts |
| AMS 2774 | Heat treatment of wrought nickel and cobalt alloy parts | 718 and similar alloys, solution and age |
A steel callout that says only "heat treat per AMS 2759" with no slash sheet and no condition is incomplete. Send it back to engineering before the RFQ, because the processor cannot choose the cycle family for you. Our 4130 vs 4340 and 17-4 vs 15-5 PH pages explain why the condition matters.
Hardness and conductivity verification
Heat treat is a special process, so the result is confirmed by testing, and the cert should report the tests. Hardness applies to most alloys; electrical conductivity is added for aluminum.
- Steel and stainless. Hardness testing, usually Rockwell, on parts or on test coupons processed with the load, with tensile tests where the spec or PO requires them.
- Aluminum. AMS 2658 sets hardness and electrical conductivity acceptance criteria for wrought aluminum parts after heat treatment, and is used to help confirm the right alloy, temper and heat treat condition. SAE lists revision E, May 2026, as current. Conductivity is reported in percent IACS. AMS 2658 covers wrought alloys, not castings.
- Who tests. If the processor tests in house, check that AC7102/5 is in its Nadcap scope for the method used. If an outside lab tests, that lab needs the approvals your prime requires.
On the PO, state which tests you want reported, the sample size if your spec leaves it open, and that results must appear on the cert with the test method. A cert that says "hardness OK" without a value should be rejected at receiving.
Sequencing heat treat with machining, plating and welding
Heat treat has to sit at the right point in the routing, and the routing has to be on the order before the first operation starts. The common sequence questions a buyer should settle with engineering:
- Rough machine, heat treat, finish machine. Leaves stock to clean up distortion and any surface affected by the furnace. Common for aluminum quenched parts and hardened steel.
- Stress relief between operations to AMS 2759/11 on steel parts that move when machined, or after welding.
- Heat treat before plating, anodize or paint, because furnace temperatures damage most finishes.
- Hydrogen embrittlement relief after plating on high strength steel, per AMS 2759/9, before any secondary conversion coating. The plater needs the part's strength or hardness to apply the right bake, so give it on the order. Our special processes page covers this step in detail.
- Post weld heat treat after all welding and any approved weld repair, since a repair can reset the sequence. See our aerospace welding services page.
- NDT and final inspection after heat treat, so cracks from quenching or straightening are found.
Straightening after heat treat is a common hidden step on long or thin parts. If it is allowed, the drawing or PO should say so, and say whether a stress relief must follow.
What goes wrong with outsourced heat treat
- Wrong or missing condition. The PO names the spec but not the H condition, temper or strength range. We confirm the final condition before release.
- Processor approved for the spec, not the alloy. The Nadcap scope or prime approval does not cover the slash sheet. We check the scope against the callout.
- Distortion with no stock left to clean up because parts were finish machined first. We raise the sequence with you when the routing does not show it.
- Late bake after plating because the plater did not know the strength level. We put the material and condition on the plating order.
- Thin certs without furnace identification, cycle reference or test values. We check each cert against the PO before the parts ship.
- Mixed lots where parts from two loads come back under one cert. We require the cert to identify each load.
What drives heat treat lead time and cost
Queue time and scheduling usually outweigh the cycle. No prices or promised lead times here; these are the drivers:
- Batch scheduling: many cycles run when a furnace load is full, and an odd cycle waits for its slot
- Long cycles such as aging, solution and age, or carburizing
- Approved source limits that leave one or two processors for your spec
- Vacuum or protective atmosphere requirements for titanium, nickel alloys and some steels
- Testing: tensile coupons take longer than hardness checks
- Transit between the machine shop, heat treater and finisher
- Straightening and rework after quench distortion
The special processes cost guide explains how outside processing adds to a part's cost.
What to send with your heat treat request
- Drawing at released revision with the heat treat callout
- Alloy and material spec, and the condition the material is in now
- Process spec and slash sheet, and the final condition, temper, strength or hardness range
- Tests to report: hardness, conductivity, tensile, and sample size if not set by the spec
- Nadcap and prime approval requirements, with the clause that invokes them
- The routing: what happens before and after heat treat, including plating and welding
- Straightening allowed or not
- Part size and weight, for furnace fit
- Quantity, need date and export classification
For machined parts that need heat treat in the routing, the aerospace CNC machining page shows how both are run as one job.
How Aerospace Sourcing handles heat treat work
We do not run furnaces and do not hold Nadcap accreditation ourselves. We place your parts with processors whose scope, approvals and furnace qualification fit your spec, and manage the work to delivery.
- One quote, one lead time, one point of contact and one purchase order, even when machining, heat treat, plating and NDT happen at different suppliers
- Spec, slash sheet, condition, tests and sequence flowed down to each supplier
- Heat treat certs checked for furnace identification, cycle reference and test values before shipment
- A certificate of conformance with every order
Export controlled drawings never go through the website; see controlled programs and confidentiality.
Request aerospace heat treating
Send the drawing, alloy, final condition and routing through the special process request form. With the slash sheet and condition up front, we can go straight to processors approved for that spec instead of asking twice. A person replies within one business day, and rush requests are prioritized.
Send the job. A person replies within 1 business day.
Part, quantity and date are enough to start. Drawings and the mutual NDA follow by reply, and controlled programs never send technical data through this site.
We have it.
Reference . A person replies within 1 business day. Watch for our email from [email protected].
Questions
What is the current revision of AMS 2750?
SAE lists AMS 2750H, dated July 2024, as the current revision of the pyrometry spec. It followed revision G, dated June 2022. Your contract or prime may still flow down a specific revision, and processors are audited to a stated revision, so check what your quality clauses require and ask the heat treater which revision its system is qualified to.
Do I need a Nadcap accredited heat treater?
If your contract, prime or drawing requires it, yes, and many primes do for flight hardware. Check the processor's AC7102 scope in PRI's Qualified Manufacturers List. The baseline comes with AC7102/S and AC7102/8 pyrometry. If the processor does its own hardness or conductivity testing, look for AC7102/5 covering the method used.
What furnace class does my part need?
Your heat treat spec sets the temperature tolerance, and the furnace must hold a class at least that tight. AMS 2750 defines six classes, with Class 1 the tightest. Ask the processor which furnace will run your parts, its class and instrumentation type, and whether its current temperature uniformity survey covers your temperature and work zone.
Which spec covers heat treating aluminum parts?
AMS 2770 covers heat treatment of wrought aluminum alloy parts, such as 2024, 6061, 7050 and 7075. Verification is often to AMS 2658, which sets hardness and conductivity acceptance criteria for wrought aluminum after heat treatment. Give the alloy and the final temper on the PO, and ask for the hardness and conductivity values on the cert.
Should heat treat come before or after machining?
Often both: rough machine, heat treat, then finish machine, so distortion and furnace affected surfaces are machined away. Heat treat comes before plating, anodize and paint. High strength steel that is plated needs a hydrogen embrittlement relief bake per AMS 2759/9 after plating. Set the sequence on the drawing or routing with engineering.
What should a heat treat cert show?
The processor, part number, quantity and lot, the process spec with slash sheet and revision, the final condition, furnace identification and a cycle record reference, and the test results with method, such as Rockwell hardness or percent IACS conductivity. If Nadcap or prime approval is required, it should reference it. Reject a cert that only says heat treated per a spec.
Related
Sources
- SAE: AMS2750H Pyrometry
- ANSI Blog: SAE AMS 2750H-2024 Pyrometry
- Example Nadcap heat treating scope listing AC7102, AC7102S, AC7102/5 and AC7102/8 (Daher)
- Metal AM: BEAMIT Nadcap heat treating accreditation, AC7102 with AC7102/S and AC7102/8
- PRI: Nadcap program overview
- BSI: AMS 2759/1 carbon and low alloy steel parts below 220 ksi
- ANSI Webstore: AMS 2759/7F carburizing (2026)
- SAE: AMS 2759/9E hydrogen embrittlement relief baking
- ANSI Webstore: AMS 2770 heat treatment of wrought aluminum alloy parts
- ANSI Webstore: AMS 2774G heat treatment of nickel and cobalt alloy parts
- DIN Media: AMS 2658E hardness and conductivity inspection of wrought aluminum parts
- Thermal Processing: heat treatment of aluminum, hardness and conductivity
Ready to
source it?
A person replies within 1 business day. NDA first.
Request a quote