Aug 14, 2026
Enclosure RFQ Checklist: 9 Specs to Send Your Supplier Before You Get a Quote
A practical enclosure RFQ checklist for buyers: the 9 specifications every sourcing email should include so the quote you receive is buildable, compliant, and comparable across suppliers.
A vague request — "stainless steel cabinet, IP66, send quote" — is the fastest way to lose two weeks. The supplier guesses at the environment, the cutouts, and the certification scope, then returns a price that does not match what you actually need. When the cabinet finally arrives, it is the wrong material for the site, the holes do not line up, or the panel is not UL 508A when the project required it.
This enclosure RFQ checklist gives you the 9 specifications to put in every sourcing email. Send these and the quote you receive is buildable, comparable across suppliers, and far less likely to come back as a costly rework.
Why the RFQ, Not the Price, Controls Your Project
Buyers often open a sourcing conversation with "what is your best price?" The price is the last number you should care about. The RFQ determines three things long before money changes hands:
- Lead time — a cabinet with custom cutouts and a UL 508A panel takes longer than an empty box. Suppliers cannot quote a realistic date until they know the scope.
- Fit — most enclosure failures in the field are not manufacturing defects. They are specification gaps: the wrong material for the chloride exposure, cutouts that collide with internal components, a coating that fails under washdown.
- Comparability — two quotes are only comparable if they describe the same product. A thin RFQ lets each supplier quietly assume a different build, so the lowest bid wins by omitting what you forgot to ask for.
Buyer takeaway: Treat the RFQ as the contract for the quote. The more precise the specification, the less room suppliers have to guess — and the fewer surprises you absorb later.
The 9 Specs Every Enclosure RFQ Should Include
1. Installation Environment and Exposure
"Outdoor" is not a specification. A cabinet on a climate-controlled warehouse wall and a cabinet 200 meters from a chlorinated cooling tower are different products. State the actual exposure:
- Atmospheric: coastal / salt spray, humidity range, temperature swing.
- Chemical: industrial fumes, washdown with solvents or caustics, dust.
- Mechanical: vibration, impact risk, public access.
- Solar: direct sun and radiant heat gain.
Buyer Decision: If the site is within a few kilometers of the coast or a pool of untreated water, write that down explicitly. It changes the material grade (see spec 2) and the coating system.
2. Material Grade (Carbon Steel, 304, or 316)
Match the material to the environment, not to a habit. Painted carbon steel is a sound economic choice for mild, indoor, or sheltered conditions. 304 stainless is the general outdoor workhorse. 316 (with molybdenum) is the starting point where chloride exposure is real — coastal, wastewater, marine, or de-icing salt.
The decision is almost always about chlorides, not about "stainless is better." Specifying 316 where 304 would do adds cost with no benefit; specifying 304 where chlorides are present invites pitting. See 304 vs 316 Stainless Enclosure: How to Choose the Right Grade for the cutoff.
3. Ingress Protection and NEMA Type
Write the protection level you need, and separate "ingress" from "corrosion." IP65/IP66 describe dust and water ingress. NEMA 4X adds corrosion-resistant construction and often a gasketed seal. They are not the same line item, and a stainless box is not automatically NEMA 4X.
- IP65: dust-tight, low-pressure water jet.
- IP66: dust-tight, high-pressure water jet.
- NEMA 4X: indoor/outdoor, corrosion-resistant, hose-down.
For the difference and when each applies, see IP65 vs IP66 Enclosure: Which Rating Do You Actually Need.
4. Dimensions, Mounting, and Wall Thickness
Give the external envelope and how it mounts:
- Width × Height × Depth (mm or inch).
- Wall-mount, floor-standing, or pole-mount.
- Enclosure wall thickness / gauge if the structure matters (heavy components, cantilevered loads).
- Door count and hinge side if it affects installation.
Do not assume the supplier will pick a standard size. If you have a footprint constraint in the panel shop, say so.
5. Cutouts, Holes, and Internal Layout
This is where most RFQs fail. A supplier cannot quote a machined enclosure from "a few holes." Provide:
- A drawing (DWG/PDF) with cutout positions, diameters, and tolerances.
- Gland plates, conduit entries, or cable glands and their sizes.
- Back panel, DIN rails, or mounting brackets you expect inside.
- Anything that must stay clear (ventilation path, the door swing).
Engineering Note: Send the drawing, not a sentence. A dimensioned drawing turns a guess into a quote and removes the single largest source of rework.
6. Thermal Management
An enclosure that traps heat will cook the components inside, regardless of how good the box is. State the internal heat load and the ambient range:
- Passive: ventilation, louvers (note IP impact).
- Active: filter fan, heat exchanger, air conditioner, or PTC heater for condensation.
- For sizing, see Best Cooling Options for Outdoor Electrical Cabinets.
If you only write "IP66," you have said nothing about temperature — and temperature is what kills the electronics.
7. Electrical Scope: Empty Box or Complete Panel
Decide and state whether you are buying an empty enclosure or a complete assembly:
- Empty enclosure — you fit the components, or a panel shop does.
- Complete control panel — PLC, VFD, HMI, breakers, wired and tested.
This changes everything: a finished panel carries different certification scope (typically UL 508A, not just UL 50/50E for the empty box), different lead time, and different test requirements. If you need a certified panel, say so up front — see UL Listed Electrical Enclosures: Sourcing from China Without the Factory Risk.
8. Certifications and Compliance
Write the certification you need and, more importantly, the scope:
- UL 508A for the assembled control panel; UL 50/50E for the empty enclosure construction.
- NEMA type and the environmental rating.
- CE, RoHS, or regional marks if the end market requires them.
- Which model family and material the certificate actually covers.
A certificate PDF is not proof the quoted construction is certified. Ask which file number and model scope applies to the exact build you are ordering.
9. Quantity, Finish, and Delivery
Close the RFQ with the commercial facts suppliers need to quote honestly:
- Quantity and whether it is a one-off or a recurring batch (MOQ may apply).
- Powder-coat color and finish standard (e.g., RAL code).
- Required delivery date and Incoterms (EXW, FOB, CIF, DDP).
- Target budget only if it helps the supplier propose the right build — optional.
Enclosure RFQ Specification Table
Use this as a template. A completed row per spec is enough to get a comparable quote from any supplier.
Spec | What to write | Why it matters |
|---|---|---|
Environment | Coastal, IP66, −10 to 45 °C | Drives material and coating |
Material | 316L stainless, 1.5 mm | Chloride resistance |
Protection | NEMA 4X | Corrosion + ingress |
Dimensions | 600×800×250 mm, wall-mount | Fit in panel shop |
Cutouts | DWG attached, 6× M25 glands | Removes rework |
Thermal | 40 W load, 60 °C ambient, AC | Protects electronics |
Scope | Complete UL 508A panel | Certification path |
Cert | UL 508A, file scope confirmed | Avoids false claims |
Commercial | Qty 5, RAL 7035, FOB Shenzhen | Enables real quote |
A Sample RFQ You Can Copy
Subject: Enclosure RFQ — outdoor control panel, coastal siteEnvironment: within 1 km of coast, hose-down washdown, −10 to 45 °C. Material: 316L stainless steel, 1.5 mm wall. Protection: NEMA 4X, IP66. Dimensions: 600 × 800 × 250 mm, wall-mount, left-hinge door. Cutouts: drawing attached (6× M25 cable glands, 1× 200×150 viewer). Thermal: internal load ~40 W, ambient up to 60 °C, air conditioner required. Scope: complete control panel, UL 508A. Certifications: UL 508A, confirmation of file scope for this build. Quantity: 5 units, recurring. Finish: RAL 7035. Delivery: FOB Shenzhen, by [date]. Please confirm certification scope and lead time.
Common RFQ Mistakes That Cost Buyers Money
- Writing only "stainless steel, IP66" and assuming the supplier will infer the rest.
- Forgetting chlorides — specifying 304 for a coastal or wastewater site.
- Treating IP and NEMA as the same requirement.
- Sending cutouts as text instead of a dimensioned drawing.
- Omitting thermal load and wondering why components fail in summer.
- Asking whether the factory is UL listed instead of whether the quoted build is covered.
- Comparing two quotes that describe different products because the RFQ was thin.
Frequently Asked Questions
How detailed does an enclosure RFQ need to be for a simple box?
Even an empty box needs environment, material, protection, dimensions, and cutouts. "Simple" RFQs fail for the same reason complex ones do: the supplier fills the gaps with assumptions. A one-line RFQ buys a one-line guess.
Should I specify 316 stainless for every outdoor enclosure?
No. 316 matters where chloride exposure is real — coast, wastewater, marine, de-icing salt. For mild outdoor or sheltered conditions, 304 is usually sufficient and cheaper. The exposure, not the word "outdoor," decides the grade.
Is IP66 the same as NEMA 4X?
Not exactly. IP66 covers dust and high-pressure water ingress. NEMA 4X adds corrosion-resistant construction. A stainless box is not automatically NEMA 4X. State both if the project requires corrosion resistance plus washdown.
Do I need a drawing for cutouts?
Yes. A dimensioned DWG or PDF removes the largest source of enclosure rework. A written description of "a few holes" forces the supplier to guess at positions and sizes, and guesses are where cabinets come back wrong.
What if I only need an empty enclosure, not a panel?
Say so explicitly. An empty enclosure is certified under UL 50/50E; a complete panel is UL 508A. Mixing the two up is the most common reason a "UL listed" cabinet does not satisfy the project's actual requirement.
Engineering Takeaway
The enclosure RFQ is not paperwork — it is the specification that the quote is built against. Nine specs cover almost every buying decision: environment, material, protection, dimensions, cutouts, thermal, electrical scope, certification, and commercial terms. Send them all, attach the drawing, and you convert a guessing game into a comparable, buildable quote.
The cheapest enclosure is the one specified correctly the first time.
Related Guides
Send Us Your Enclosure Specification
If you have a drawing, a site condition, or just a loose idea of what the cabinet must survive, send it to UniRegal. We review the specification first and match the build to the right material, protection, and certification scope — rather than forcing your requirement into whatever one workshop happens to stock.