Heat Treatment Services for Custom Metal Parts

Heat treatment services are controlled heating and cooling cycles that change a metal part's internal structure without changing its shape. The goal is a defined property: hardness, tensile strength, ductility, toughness or relief of residual stress from machining and welding.

The service fits engineers and procurement managers who need a part to meet a mechanical property callout, not just a geometry callout. It is used when a drawing specifies a temper, a hardness range or a stress-relief step, and when a machined or formed part must be stabilized before final finishing.

When to specify heat treatment

• The drawing calls out a temper such as 6061-T6 or a hardness range in HRC or HB.
• A welded or heavily machined part needs stress relief to hold dimensions.
• A wear surface needs a harder case than the core material provides.
• A forming or bending operation needs an annealed or softened condition first.
• A part must meet a customer or industry specification that names a heat treat cycle.

Heat treatment services are controlled heating and cooling cycles that change the hardness, strength or stress state of metal parts. A typical job follows a fixed sequence from incoming material to released parts, and each step is recorded against a lot.

1. 1. Review the requirement Confirm alloy and grade, target temper or hardness, drawing limits, quantity and any referenced standard.
2. 2. Incoming inspection Check material certification, part identity and condition. Parts with scale, oil or damage are flagged before the cycle.
3. 3. Clean and prepare Degrease and dry the parts, then rack them so they are supported and evenly exposed.
4. 4. Heat to the set point Soak at the specified temperature for the specified time. Furnace temperature and soak time are recorded.
5. 5. Quench or cool Cool at the controlled rate the process sheet requires, using the named medium and method.
6. 6. Age, temper or stress relieve Run the second thermal step where required, such as artificial aging for 6061-T6 or tempering after hardening.
7. 7. Verify and release Check hardness or other specified properties, review records and release the lot with the documents the drawing requires.

Require lot traceability, process records and certificates where risk warrants. That record set lets a buyer prove the parts met the callout.

Heat treatment services cover the common engineering metals, and the cycle changes with the alloy family. The table lists each family and how it is typically treated.

Finishes applied after heat treatment

• Anodizing: clean, etch, anodize aluminum, optionally dye, seal and dry. Adds corrosion and wear resistance; dimensions and color can vary with alloy and geometry.
• Electroplating: clean, activate, deposit metal, rinse and dry. Thickness is weaker in recesses and stronger on edges.
• Conversion coating: phosphate or chromate chemistry improves paint adhesion and corrosion resistance.
• Powder coating: apply dry powder, then heat and cure. Curing temperature may affect substrates and dimensions.
• Passivation: chemically treat clean stainless steel to remove free iron. It does not remove scale or repair poor surface condition.

Heat treatment specifications and tolerances depend on the process, substrate, geometry and drawing requirements. The table gives typical ranges and standards for the finishing steps that usually follow heat treatment.

Lead time is typical and depends on the cycle, alloy and supplier load. Confirm it at quote stage.

Most cost comes from the cycle itself and the handling around it. These choices reduce both.

• Specify the property, not just the process name. A hardness range or temper callout lets the supplier pick the most efficient cycle.
• Use one alloy and one temper across a family of parts so lots can be combined in a single furnace run.
• Keep wall sections as uniform as possible. Thick-to-thin transitions drive longer soak times and higher distortion risk.
• Add a machining allowance where distortion is likely, then finish-machine after treatment.
• Avoid sharp internal corners and abrupt section changes that concentrate stress during quenching.
• State masking and finish requirements on the drawing so post-treatment steps are quoted once, not added later.
• Group parts by size and cycle so the supplier can load the furnace efficiently.

Heat treatment appears wherever a part must carry load, resist wear or hold tolerance after machining.

Automotive work often pairs heat treatment with a documented process record, because the part's function depends on the property result rather than appearance alone.

Heat treatment cost is set by the cycle and the handling, not by a single rate. The main drivers are listed below.

• Cycle type and duration: solution treatment plus aging, hardening and tempering, or stress relief each carry different furnace time.
• Alloy and grade: some alloys need tighter temperature control or a specific quench medium.
• Part size and quantity: furnace load is limited by volume and weight, and small lots that cannot be combined carry more setup per part.
• Fixturing: parts that need custom supports or spacing take more labor.
• Verification: hardness testing, process records and certificates add inspection time.
• Post-treatment steps and distortion risk: machining allowances, straightening or finishing add operations.

Ordering heat treatment services through SR means working with a manufacturing broker that does not own factories or machines. SR collects quotes from a vetted supplier network, manages quality and inspection, and delivers parts.

• Vetted supplier network: suppliers are matched to the alloy, cycle and quantity in the RFQ.
• One contact: SR manages the quote, order and delivery through a single point of contact.
• Inspection managed by SR: hardness results, process records and dimensional checks are reviewed against the drawing.
• Quote turnaround: 5-7 working days from a complete RFQ package.

Send drawings and requirements to killol@sourcingrepository.com, or use the quote form. SR is based at 201 SG Mall, Ahmedabad.