Not all sheet metal fabricators are equal. Two shops quoting the same part can differ enormously in quality, reliability, documentation, and true delivered cost. For aerospace, defense, and other high-reliability programs, the wrong supplier can mean failed inspections, missed deliveries, or compliance gaps that put your program at risk. Below are the seven factors that separate a capable, low-risk fabrication partner from a shop that just cuts metal — and how MJM Manufacturing measures up on each.

Certifications are the fastest way to gauge whether a fabricator can meet your quality and regulatory requirements. They aren’t marketing — they represent audited, third-party-verified systems. What to look for depends on your industry: aerospace and defense demand more than commercial work.

For aerospace and defense programs, the baseline is AS9100 (aerospace quality management) and ISO 9001. If your parts involve controlled technical data, the supplier must be ITAR registered, and for government contracting they need a CAGE Code and active SAM.gov registration. Welded aerospace assemblies require AWS welding certifications such as AWS D17.1. For commercial and industrial work, ISO 9001 is the essential baseline.

MJM holds 17 certifications, including AS9100, ISO 9001, ITAR registration, AWS D17.1 with Lockheed Martin program approval, DFARS compliance, DBE, and CAGE Code 0YLX1 — see the full list on our certifications page.

Ask a supplier: “Which certifications do you hold, and can you provide current copies for our vendor package?”

A fabricator is only as capable as the equipment on its floor. Confirm the supplier can actually perform every process your part needs — cutting, forming, welding, machining, finishing — and that they have the capacity to hit your volumes and lead times. Ask whether the work is done in-house or subcontracted out, because outsourced processes add cost, time, and quality risk.

Match the equipment to your part. Thick plate needs high-power laser cutting; long parts need a large press brake; aerospace assemblies need certified welding and precision inspection. MJM runs over 40 machines including five Amada laser cutting systems, nine press brakes (to 240 tons / 14 ft), nine IPG fiber laser welders, a Mazak CNC machining center, and automated inspection — see the full equipment list.

Ask a supplier: “Which of these processes do you perform in-house versus subcontract?”

A single-source fabricator that handles cutting, forming, welding, machining, finishing, and assembly under one roof almost always beats coordinating several specialty shops. Every hand-off between vendors adds markup, shipping time, scheduling complexity, and a new point where quality or accountability can slip. When one supplier owns the whole process, there’s a single point of responsibility for your finished part.

Single-sourcing also shortens lead times and simplifies your purchasing. MJM is a fully integrated single-source manufacturer, delivering complete parts and assemblies from prototype through production — explore our full range of fabrication services.

Ask a supplier: “Can you deliver a finished, assembled part — or only individual processes?”

A quote is meaningless if the parts don’t pass inspection. Evaluate how a fabricator actually controls and verifies quality: What inspection equipment do they run? Can they provide first article inspection (FAI) reports, material certifications (MTRs), and in-process records? Do they have a documented, audited quality management system — not just a promise of “good work”?

Modern inspection matters. Automated optical inspection and CMM measurement catch out-of-tolerance conditions that manual measuring misses. MJM verifies parts with the Amada Fabri-Vision automated optical system and Keyence CMM, all under an AS9100 and ISO 9001 certified quality system, with full documentation available for aerospace and defense programs.

Ask a supplier: “Can you provide FAI reports, MTRs, and inspection documentation with our order?”

A great price means little if the parts arrive weeks late. Ask about realistic lead times, current capacity, and how the shop handles rush orders and production spikes. A fabricator running many machines has the redundancy to keep your job moving even when one line is busy — a single-machine shop can stall your program if that machine is tied up or down.

Responsiveness is a signal, too. How fast does the supplier return a quote? MJM returns most quotes within 24 to 48 hours, and our multi-machine floor provides the capacity to support both quick-turn prototypes and high-volume production runs.

Ask a supplier: “What’s your typical lead time, and how do you handle rush or high-volume orders?”

The lowest quoted price is not always the lowest total cost. Look at the all-in, delivered cost of a finished part: per-part price, tooling, freight, and the hidden costs of rejects, rework, and late deliveries. A cheap part that fails inspection or arrives late costs far more than its quote.

Distance is often misjudged. Freight is one of the smallest and most visible line items, while labor rates and overhead — which vary a lot by region — usually move total cost far more. A shop in a lower-cost region can deliver a lower total landed cost even after shipping. We break this down in our guide to total landed cost.

Ask a supplier: “What’s the all-in delivered cost, including tooling and freight?”

Finally, consider how long the fabricator has been in business and who they serve. A long operating history, long-tenured staff, and a roster of demanding repeat customers are strong signals of reliability — the kind of institutional knowledge and craftsmanship a brand-new shop simply can’t replicate. Repeat business from serious customers is the truest measure of quality and service.

MJM has manufactured in Miami since 1979 — 47 years — and serves long-standing customers including Boeing, Lockheed Martin, Northrop Grumman, L3Harris, and many others across the industries we serve.

Ask a supplier: “How long have you been in business, and who are your long-term customers?”