If you place orders for a living - even if ordering is only 20% of your job - you've probably had this moment. Someone sends a request: 'We need the Eaton bathtub resin.' Or: 'Get me 7/16 hydraulic hose.' Or: 'Do we have air hose 1/4 or 3/8?'
I'm the office administrator for a 42-person packaging company. I manage roughly $140,000 in annual purchasing across 11 vendors. When I took over in 2020, I discovered that most order mistakes weren't caused by bad suppliers. They were caused by vague specs.
This is the checklist I now use before any non-commodity purchase. It has five steps and takes about ten minutes. Plus, it works for plastic, resin, and hose. It won't replace the expertise of an engineer, but it will stop you from ordering the wrong material, wrong size, or wrong color.
Step 1: Separate the brand from the spec
Take 'Eaton bathtub resin.' In that phrase, 'Eaton' is either a brand, a source, or the name someone half-remembers from a contractor. None of those is a specification. A resin is not a resin; it's epoxy, polyester, acrylic, or something else - or rather, it depends on the application. If someone says 'just use this product' without a code, that's a red flag.
My rule: treat the brand as a clue, not the answer.
- Ask for the exact product name and code on the container or data sheet.
- Ask for the technical data sheet (TDS) and safety data sheet (SDS).
- Identify the chemistry: epoxy, polyester, PET, etc.
- Identify the application: casting, coating, laminating, repair.
- If the requester can't provide a code, ask them to send a photo of the label.
I ignored this once. A vendor's 'compatible' resin looked right but didn't cure. The product had to be stripped and redone. The vendor would not take back the opened container. (Honestly, I don't blame them.)
Step 2: Turn material names into measurable attributes
'PET coyote' is a good example. PET is the material. Coyote is a color - or maybe a shade, or a finish, or a product line. It is not a thickness. It is not a grade. It is not a guarantee of food contact or UV stability.
For sheet, roll, or film, I write down these fields:
- Material family: PET, PETG, PVC, PP, ABS, etc.
- Thickness and tolerance
- Sheet or roll dimensions
- Color code (Pantone, RAL, or supplier code)
- Finish on each side (gloss, matte, textured)
- Required certifications (FDA, UL, RoHS, etc.)
- Minimum order quantity
Most buyers focus on price and thickness. They miss the color code and the finish. That's the blind spot. I once ordered PET with 'coyote brown' written in the comments and got a color that was closer to orange. The supplier wasn't at fault - I hadn't provided a code.
Oh, and if sustainability claims matter, ask directly. Per FTC Green Guides (16 CFR Part 260), a 'recyclable' claim has to be substantiated. A supplier can say 'recyclable' if it is actually collected for recycling in the market where it is sold. A color nickname doesn't prove that.
Step 3: Treat size as incomplete without limits
'7/16 hydraulic hose' is a dimension, not a spec. Seven-sixteenths of an inch can be the inside diameter - or rather, it can be the outside diameter, or the size of the fitting, depending on the hose assembly. It doesn't tell you the working pressure, the burst pressure, the reinforcement, the end fittings, or whether the hose is compatible with the fluid.
Checklist for any hose or tubing order:
- Inside diameter and outside diameter (with units stated)
- Working pressure and min/max burst pressure
- Temperature range
- Reinforcement (textile braid, wire braid, spiral, etc.)
- Fluid compatibility
- End fitting type and thread size
- Relevant standards (SAE, ISO, DIN) or test certification
If the request says only '7/16 hydraulic hose,' your first question should be: 'Can you read the marking on the hose that has worked before?' The printed line on the hose is the best source. (Should mention: hoses usually have a specification line printed on the cover. It's worth asking for a photo.)
Step 4: When comparing air hose sizes, compare flow, not just diameter
The eternal question: air hose 1/4 vs 3/8 - which one? The simple answer is: 3/8 allows more flow for a given length and pressure. But that doesn't tell you which one to buy.
Here's how I (with help from our maintenance lead) now decide:
- Find the tool's air consumption in SCFM (standard cubic feet per minute) at your compressor's pressure.
- Remember that a long small-diameter hose causes pressure drop. At 50 feet, a 1/4 hose can starve a tool that runs fine on a 10-foot coil.
- Use 1/4 for lighter tools: brad nailers, blow guns, air chucks, tire inflators.
- Use 3/8 for higher-flow tools: impact wrenches, spray guns, grinders, ratchets. For those, 3/8 is a no-brainer.
- Check the connector size. A hose can have 3/8 inside diameter and still have 1/4 NPT fittings - or vice versa. The part number matters.
- If you're on the fence, buy a 3/8 hose for the workbench and a 1/4 coil for pin nailers. That's not a lazy answer; it's the one that keeps the shop working.
The 'just get 3/8 because bigger is better' thinking comes from an era when tools were simpler. Today, matching hose size to tool flow is cheap insurance.
Step 5: Create a reusable order spec sheet
The first four steps are per-order. The fifth is the one most people ignore: write your specs down in a template and use it for reorders.
I have a one-page spec form that must be filled out before I submit a PO. For materials, it includes material, thickness, color, finish, dimensions, certification, and 'other.' For hoses, it includes ID, OD, pressure, fittings, standard, and the photo of the part number. If the form has blanks, the order doesn't go out.
Why? Because the third time we ordered the wrong quantity was the last time I trusted memory. (Should mention: the first wrong order was the resin incident above. The second was a hose with the right end thread but the wrong length. The third was the color code.)
We now process 60-80 orders a year through that form. It cut my wrong-order rate from four a year to one, and that one was the vendor's own catalogue error. (Surprise, surprise.) The template was a game-changer. The 10 minutes of verification has saved an estimated $6,000 in restocking fees and rework - so far.
What this checklist doesn't do
This isn't a substitute for engineering. If the application is high-pressure hydraulic, get the engineer to approve the spec. If the sheet needs to be food-contact grade, get the documentation.
Common mistakes to avoid:
- Ordering by phrase only: 'Eaton bathtub resin' or 'PET coyote' are clues, not PO lines.
- Ordering by one dimension: '7/16 hydraulic hose' needs more data.
- Comparing hoses only by diameter: air hose 1/4 vs 3/8 depends on CFM, length, pressure, and fittings.
- Repeating an old product name without checking the label - the label may have changed.
Bottom line: 5 minutes of checking beats 5 days of correcting. It's the cheapest insurance you'll buy in procurement.