Make or Buy for Insulation Parts

Make or Buy for insulation parts describes the sourcing decision whether a company produces stamped, cut and formed insulation parts in-house or awards them to a contract manufacturer. The decision rarely turns on unit price alone. What counts is the utilisation of your own machines, material knowledge, the required tolerances, tooling costs and the risk of scrap. For insulation parts made of Nomex, pressboard, mica or polyester film, the material cutting is demanding, because the material is expensive and edges must stay clean. This is exactly where a sober comparison pays off.

What Make or Buy means for insulation parts

Make means in-house production: your own presses, cutting lines, tooling and trained staff. Buy means awarding the work to a specialist who provides material, machines and inspection. Between the poles lies partial outsourcing, for example only the tooling or only the series. For insulation parts it is often not the machine that decides, but the material knowledge: which material holds the thermal class, how a laminate behaves during stamping, how to avoid delamination at the cut.

Cost comparison: in-house versus outsourcing

The bare unit price hides the true cost. A sound comparison uses the full cost of both routes.

• In-house: machine depreciation, set-up time, tooling, material purchasing in small quantities, scrap during the learning curve, tied-up staff, storage space.
• Outsourcing: unit price including material, one-off tooling cost, logistics, but no machine commitment, no scrap risk, plannable capacity.
• Hidden items: ramp-up and qualification of new parts, sampling, documentation, rework in case of tolerance deviations.

A rule of thumb from practice: the higher the variant diversity and the more expensive the material, the sooner outsourcing pays off. At very high, constant volumes with simple material, in-house production can be cheaper.

When outsourcing is the better choice

• Many variants in small to medium lots, where your own set-up costs dominate.
• Expensive special materials such as Nomex, Kapton or mica, where scrap really hurts.
• Tight tolerances and inspection duties that your own processes do not yet hold reliably.
• Demand peaks that would overload your own machines.
• New materials for which in-house processing knowledge is missing.

Selection criteria for a contract manufacturer

Once the buy decision is made, the choice of partner determines quality and delivery reliability. These criteria separate a suitable from an unsuitable supplier.

• Material competence: experience with exactly your material, from aramid paper to polyester film, including sources of supply.
• Machine park: suitable processes for your geometry, from roll and contract slitting to stamping and forming.
• Tolerances: demonstrable process capability within DIN ISO 2768, documented rather than claimed.
• Quality system: certification to ISO 9001, traceability, first-article inspection.
• Logistics: delivery concepts such as a consignment warehouse or Kanban for constant availability.
• Communication: fast, technical quotes and a fixed contact person.

Typical mistakes when awarding the work

• Comparing only the unit price and ignoring tooling, sampling and scrap.
• Not specifying tolerances cleanly and later arguing about rework.
• Leaving the material open instead of fixing type and thermal class.
• Choosing a partner without material experience on price and paying for quality later.

How a request at GOBA works

1. Send a drawing or sample, with material, tolerances and quantity.
2. GOBA checks feasibility, material and process and prepares a technical quote.
3. Sampling with an approval sample, then series start.
4. On request, a stock concept for constant availability.

GOBA Takeaway

For insulation parts, Make or Buy is a calculation about full cost, not about unit price. Anyone who produces expensive materials, tight tolerances and many variants is usually cheaper and safer with an experienced contract manufacturer, because scrap, tooling and material knowledge are pooled there. GOBA has been producing stamped and cut insulation parts since 1959 and advises from the first drawing to the series. Send us your requirement through our stamping and forming or contract slitting, and you will receive a technical quote. For the make-or-buy assessment, use our consulting and service.

FAQ on Make or Buy for Insulation Parts

From what quantity does outsourcing insulation parts pay off?

There is no fixed threshold. What matters is variant diversity and material value. With many variants, expensive materials and tight tolerances, outsourcing often pays off even at small series, because set-up costs and scrap risk are pooled at the contract manufacturer.

What documents does a contract manufacturer need for a quote?

A drawing or sample, the desired material with thermal class, the tolerances and the quantity. The more precise the information, the more reliable the quote.

Are there tooling costs and when do they pay off?

For stamped parts there is usually a one-off tool. It pays off over the series. For small series or prototypes, tool-free processes such as roll slitting or kiss-cut are often the cheaper choice.

How long does an approval sample take?

This depends on the material and the tooling situation. For tool-free cuts, samples are available quickly, for new stamping tools it takes longer. GOBA states the lead time in the technical quote.