Quoting Parts That Need Heat Treatment

Heat treatment is one of those manufacturing steps that looks simple on a drawing — a single line item like “harden to 50 HRC” — but quietly derails quotes if you don’t account for the full picture. For CNC shops, 3D printing services, and sheet metal fabricators, quoting heat-treated parts means factoring in outsourcing costs, distortion allowances, extra handling, and schedule uncertainty. Miss any of those, and you either lose margin or lose the job.

Identify the Real Heat Treatment Scope

Start by clarifying exactly what the customer needs. “Heat treat” covers a wide range: through-hardening, case hardening (carburizing, nitriding), annealing, stress relieving, tempering, and precipitation hardening for certain alloys. Each has different temperature cycles, atmospheres, and distortion profiles.

Ask for the specification (AMS 2759, AMS 2770, AMS-H-6875, etc.) and the required hardness range or case depth. If the print only says “heat treat to 45-50 HRC,” push for the governing spec. That spec determines the process, which drives your subcontractor selection and cost.

Account for Outsourcing Realities

Most digital manufacturers don’t run their own heat treat furnaces. You’re quoting a vendor’s price plus your markup and coordination effort. Get current quotes from at least two heat treat suppliers for the specific material, geometry, and spec. Prices vary significantly by batch size — a partial load costs far more per pound than a full furnace run.

Include these often-overlooked line items:

• Minimum lot charges
• Racking or fixturing fees for complex geometries
• Atmosphere surcharges (vacuum, endothermic, nitrogen)
• Straightening or press-quenching add-ons
• Certification and paperwork costs (material certs, process records)

Build in a coordination buffer — typically 15-25% on the vendor quote — for your time managing the handoff, inspection, and potential rework.

Model Distortion and Machining Allowances

Heat treatment distorts parts. The amount depends on material, geometry asymmetry, quench severity, and fixturing. If you’re machining before heat treat, you need to leave enough stock for post-HT grinding or machining to hit final dimensions. If you’re machining after, you need to quote the extra operations.

For quoting purposes, apply a distortion allowance based on historical data or the heat treater’s guidance. Common rules of thumb:

• Through-hardening: 0.001-0.003″ per inch of section thickness
• Carburizing: 0.002-0.005″ per inch, plus potential growth from retained austenite
• Nitriding: minimal distortion (0.0002-0.0005″ per inch) but longer cycle times

If the part has tight tolerances (< ±0.001") or critical datums, factor in post-HT grinding, honing, or EDM. Quote those operations explicitly rather than burying them in a contingency.

Schedule the Thermal Cycle Realistically

Heat treatment adds calendar days — not just furnace time. A typical outsourced cycle looks like:

1. Ship to heat treater: 1-2 days
2. Wait for batch consolidation: 1-5 days
3. Furnace cycle: 1-3 days (nitriding can be 24-72 hours at temperature)
4. Cool down and straighten: 1 day
5. Ship back: 1-2 days
6. Incoming inspection at your shop: 0.5-1 day

That’s 5-14 working days of pure lead time before you can finish the part. Quote the lead time honestly. If the customer needs it faster, offer expedited heat treat (premium pricing, dedicated furnace run) as a separate line item so they see the cost of speed.

Handle Material Certification and Traceability

Heat treatment often requires material certs upfront (mill certs showing chemistry) and generates its own paperwork (process charts, hardness maps, tempering records). Aerospace and medical jobs may need NADCAP-accredited suppliers and full traceability to the heat lot.

Quote the administrative time for:

• Reviewing incoming material certs before shipping
• Creating heat treat work instructions for the vendor
• Receiving and reviewing vendor paperwork
• Building the final certification package for the customer

This is 1-3 hours of skilled admin time per heat treat lot. Don’t absorb it.

Quote the Risk of Rework or Scrap

Parts can crack, warp beyond salvage, or miss hardness specs. The risk is higher for:

• Complex geometries with thick-to-thin transitions
• High-carbon or air-hardening tool steels
• Parts with sharp internal corners (stress risers)
• Large flat plates (warpage)

Include a risk contingency — typically 5-10% of the part value — for high-risk geometries. Alternatively, quote a “heat treat first article” where you send one or two parts through the full cycle before committing the full lot. This protects both you and the customer.

Present the Quote Clearly

Break the heat treatment portion into its own section on the quote:

• Heat treat process (per spec)
• Vendor cost (pass-through with markup shown)
• Distortion allowance / post-HT machining ops
• Expedite option (if applicable)
• Certification and traceability admin
• Risk contingency or first-article option
• Added lead time (calendar days)

This transparency builds trust. Customers see exactly what they’re paying for and why the lead time is what it is. It also makes change orders easier — if they change the spec from oil quench to vacuum, you have a clean baseline to reprice.

Automate the Repeatable Parts

If you regularly quote parts that need the same heat treat processes, build the logic into your quoting engine. Store vendor rate cards by process and material. Pre-load distortion allowances by geometry class. Auto-calculate added lead time based on the heat treater’s current schedule.

Solvi’s instant quoting engine lets you define these process-specific rules once, then apply them automatically to every RFQ that calls out heat treatment. You get consistent, accurate quotes in minutes — not hours of spreadsheet work. See how it works.