What does a material report from Hau Chang contain?
Composition from the spectrometer, hardness results for the heat-treatment batch, and dimensional results where inspection is specified. Metallographic images and fatigue data are added when the part calls for them. Tell us at quotation stage what documentation your process requires so it is planned in, not retrofitted.

Why use a spectrometer instead of a conductivity meter?
A conductivity meter reads electrical conductivity, which shifts with temper as well as alloy. After T6 it cannot reliably separate 6061 from 6066. Optical emission spectrometry reads the actual elemental composition, so the alloy is confirmed rather than inferred. Incoming material is verified this way before it reaches the press.

What testing does Hau Chang perform in house?
Optical emission spectrometry for full elemental composition, hardness testing on every heat-treatment batch, color metallography for grain structure, CMM for dimensional inspection, and a fatigue rig for load-life verification. Spectrometry, metallography and fatigue testing are run to requirement rather than on every batch — tell us what the part needs and we will confirm what is included.

Is there a minimum order quantity?
There is no fixed MOQ. Sample and prototype runs can start from a single piece, depending on part complexity and die setup. Production runs typically begin around 500 pieces. Each inquiry is evaluated on its own, so send your target quantity with the drawing.

What part sizes suit closed-die forging at Hau Chang?
Most parts we run fall between 150 and 420 mm in their longest dimension. That is where our press capacity and die sizes are most economical. Parts outside that range are not refused outright. Feel free to send the drawing and we will assess feasibility case by case.

Which aluminum alloys can Hau Chang forge?
Heat-treatable alloys only: 2xxx (2014, 2024), 6xxx (6061, 6082) and 7xxx (7050, 7075). Non-heat-treatable series such as 1xxx, 3xxx and 5xxx, and casting alloys, are outside our process window. If your drawing calls for one of those, tell us the mechanical requirement and we will suggest a heat-treatable equivalent.

What is the difference between forging and casting?
Casting pours molten metal into a mold; the grain forms as it solidifies, with pores and shrinkage as ready-made crack starters. Forging deforms solid metal under a die; the grain is elongated along the flow and follows the part shape. Forgings are denser, tougher and far better in fatigue, which is why they are used for parts that carry cyclic load.

Why forge instead of machining from bar?
A part machined from bar keeps the bar's grain, and machining across it exposes cut grain ends at the surface where fatigue cracks start. A forging has grain flow that follows the part shape, so strength is highest where the load runs. Forging also uses less material and less machining time on a production quantity.

When does forging make sense over casting or machining?
When the part carries cyclic or impact load, when weight matters and a thinner section has to hold the same load, and when quantities justify a die. For a simple bracket in small numbers, machining from bar may be cheaper; send the drawing and we will tell you.

What is grain flow and why does it matter?
Under the die the metal's grain is stretched along the direction of flow and follows the shape of the part. Where grain flow runs parallel to the service stress, fatigue strength and toughness are highest. Grain flow is set by the die and parting line at the development stage; it cannot be added later.

What aluminum alloys do you work with?
We specialize in heat-treatable aluminum alloys — primarily the 6xxx series (6061-T6, 6082-T6), 7xxx series (7075-T6), and 2xxx series (2014, 2024). These alloys are selected for their strength-to-weight ratio, machinability, and response to T6 heat treatment. We do not work with non-heat-treatable series such as 1xxx, 3xxx, or 5xxx.

What is the difference between 6061-T6 and 7075-T6?
6061-T6 offers a good balance of strength (about 310 MPa tensile), corrosion resistance and machinability, and is the usual choice for general structural parts. 7075-T6 is significantly stronger (about 572 MPa) with a higher strength-to-weight ratio, suited to parts where strength is the priority and the part will be protected from corrosion, at higher material cost.

Can you verify the elemental composition of incoming raw materials?
Yes. Optical emission spectrometry on a Bruker Q4 TASMAN confirms the full composition against the ASTM specification. It is done when a job calls for it, and the report stays with the batch through production.

How do you determine optimal heat treatment parameters for each alloy?
Parameters are set per alloy and section thickness. When composition data is available for the batch, thermodynamic calculation refines the solution temperature and quench window. For 6061 the validated cycle is solution treatment at 530 to 550 °C, water quench, and aging at 177 °C.

Can you source raw material, or does the customer need to provide billets?
We handle raw material procurement as part of our standard service, sourcing billets from qualified suppliers. OES verification of incoming material is available when a job calls for it. Customers may also supply their own material; please discuss before order confirmation.

What is your production workflow from raw material to finished part?
Our standard workflow:
Step 1

Incoming material OES inspection

Step 2

Billet cutting & heating

Step 3

Aluminum forging (die forging)

Step 4

Edge trimming

Step 5

Solution treatment (T4)

Step 6

Aging treatment (T6)

Step 7

CNC machining

Step 8

Surface treatment

Step 9

Dimensional inspection (CMM)

Step 10

Final visual inspection & packaging.

Steps may vary depending on part requirements.

Is your forging line automated?
A robotic arm handles billet loading and transfer on the presses, so cycle timing, billet placement and die contact are consistent from first part to last.

Can you handle forging and CNC machining under one roof?
Yes. Forging, heat treatment, and CNC machining are all performed in-house. This eliminates inter-factory logistics, reduces lead time, and allows our engineering team to coordinate process parameters across the full production flow — which is critical for achieving consistent mechanical properties.

Do you provide heat treatment in-house?
Yes. Solution treatment, quench and aging run in our own furnaces. Parameters are set per alloy and section thickness, and hardness is checked on every load before parts move to machining.

What surface treatments do you offer?
Sandblasting, anodizing, laser engraving and pad printing. Discuss your requirements during DFM review.

Can you produce prototype / sample parts before mass production?
Yes. We offer prototype and sample runs prior to mass production commitment. Sample quantities are discussed based on part complexity and mold requirements. Our workflow includes a DFM (Design for Manufacturability) review of your drawing before sample production begins.

What file formats do you accept for part drawings?
We accept 2D drawings in PDF and DXF formats, and 3D models in STEP and IGES formats. If you have a physical part for reverse engineering, our 3D scanning system (installed 2025) can capture the geometry directly. For inquiry submission, you can upload files directly via our Contact form (PDF, DXF, STEP, JPG, PNG, max 10MB).

Do you design the forging die / mold in-house?
Yes. We design and manufacture our own forging dies in-house. Die design is checked with forming simulation to predict material flow and fill before tooling is cut, and a 3D scanner verifies the finished die against the CAD model.

Are you ISO 9001:2015 certified?
Yes, Hau Chang Enterprise is ISO 9001:2015 certified. Our quality management system covers the full production flow from incoming material inspection to final shipment. A copy of our certificate is available upon request.

Do you perform 100% inspection on all finished parts?
Our standard inspection protocol includes 100% visual inspection and sampling-based dimensional inspection using CMM. For safety-critical applications or customer-specified requirements, 100% CMM inspection can be arranged. We also use Rockwell hardness testing for post-heat-treatment verification.

What metrology equipment do you have?
Our metrology lab includes: Zeiss CMM (high-accuracy 3D coordinate measuring machine), Rockwell hardness tester, fatigue testing machine (self-designed), Bruker Q4 TASMAN OES, color metallographic microscope, and fluorescent penetrant testing (FPT) equipment for crack detection.

What tolerances can you hold?
As-forged surfaces typically hold ±0.25 mm depending on part size; machined features hold standard CNC tolerances per the drawing. Tighter tolerances are reviewed at the DFM stage.

Can you provide material test reports (MTR)?
Yes. We can provide material test reports including OES elemental composition analysis, hardness test results, and phase transformation data. For projects with specific certification requirements, please discuss documentation requirements before order placement.

How do you detect internal defects or cracks?
We use fluorescent penetrant testing (FPT) to detect surface and near-surface cracks in forged parts. This is a non-destructive testing (NDT) method particularly effective for identifying forging laps, cold shuts, and fatigue cracks.

What is your minimum order quantity (MOQ)?
We do not have a fixed MOQ. Sample / prototype runs can start from a single piece depending on part complexity and mold setup. Standard production runs typically begin around 500 pieces, but we evaluate each inquiry individually. Contact us with your target quantity and we'll assess feasibility.

Who owns the forging die?
The customer pays for the die and owns it. Dies are stored and maintained at our factory and used only for that customer's parts.

Do you sign NDAs?
Yes. We can sign your NDA or provide ours before drawings are exchanged.

Can you help with design changes after the first sample?
Yes. Sample review usually leads to small adjustments to fillets, draft or datums. We update the die and re-sample before production.

How long does a quotation take?
Typically 4 to 7 business days after we receive the drawing. Parts that need forming simulation or a die concept may take a few days longer.

What information do you need to quote?
A drawing or 3D model of the finished part, the expected annual quantity, and any surface treatment or tolerance requirements. Alloy can be discussed together if not yet decided.

What is your typical lead time?
Lead time depends on part complexity, mold status, and current production schedule. For new parts requiring new molds: typically 4–6 weeks for sample production. For repeat orders with existing molds: typically 3–4 weeks for standard quantities. Please contact us for a specific project assessment.

Do you work with customers outside of Taiwan?
Yes. We serve customers globally, including in Japan, Europe, and North America. Inquiry, DFM review, and quotation can be handled entirely remotely. We ship finished parts internationally via air freight or sea freight depending on quantity and urgency.