Notes for owners · Sales management
Engineering plastics enquiries: the questions that qualify the buyer
The three questions an engineering plastics maker or stockist should ask before quoting, in what order, and how each answer decides whether to quote, ask more or decline.
The GullySales team · Updated 17 Oct 2026 · 6 min read
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The trouble with an engineering plastics enquiry is the grade. "Nylon bush, 40 OD, 20 pieces, best rate" could be a pump repair, a conveyor in a cold store or a student project, and the word nylon covers grades that behave very differently. Three answers decide whether you can quote at all: the material, or the problem the buyer is solving; what the part goes through in use; and how many, now and over a year. Ask in your first reply, before you price anything. The wrong grade quoted quickly comes back as a failed part with your name on it.
The material on the enquiry is often a guess
Buyers use "nylon" for many of the white plastics they have handled. It may mean cast nylon, a moulding grade, a glass-filled grade or whatever the last supplier sent. Others name the material that failed and want the same again.
That matters more here than in metal. Engineering plastics behave very differently in heat, water and sunlight. Nylon takes up water and grows. Some grades soften well below the temperature a machine part can reach. A rate quoted against the wrong grade is not a rate at all. It is a promise you cannot keep, made before you knew what the part has to do.
Ask in this order
Send this as your first reply, on email or WhatsApp, with a line thanking them for the enquiry. Keep it to these questions. A buyer will answer four short questions and ignore fourteen.
- Material. Which grade does the drawing or the old part specify? If you are not sure, what is the part for, and what went wrong with the last one?
- Use. What does the part go through at work: the running temperature and the highest it reaches, water or steam, oil or chemicals, load and speed, sunlight?
- Quantity. How many do you need now, and how many in a year if this works?
- Paperwork. Does your drawing or your customer ask for a certificate or a specific approval?
The first three decide whether you quote. The fourth decides what goes with the quotation. If the buyer sends a drawing, read the title block before asking anything; the grade may already be there. If the buyer has the old part, ask for a photograph of the worn face. Where and how it wore says more than what it is made of. Directory enquiries carry even less, and our post on qualifying a directory enquiry in two minutes covers the call that follows them.
What each answer tells you
| Answer | What it tells you | Your move |
|---|---|---|
| A grade from a drawing, with a revision | A design engineer, a defined part | Quote against the grade; ask only about use |
| "Same as the old one", with a worn sample | A maintenance buyer replacing a part | Ask why it wore; offer the same grade or a better one, priced both ways |
| No grade, but the use is described | A problem to solve | Suggest two grades with a reason each; let their engineer choose |
| Hot water, steam or a chemical named | Grade choice is the whole job | Check the grade's limits with your supplier before quoting |
| A flame, food or electrical rating asked for | A certified claim | Quote only what your supplier certifies; refer the rest to their adviser |
| No answer to any question | A price check or a list being filled | One standard-rate reply, then move on |
Quantity decides the route: machined or moulded
Small quantities are machined from rod, tube or sheet. Larger ones may justify a mould. The decision rule is simple. Work out what moulding saves you per piece compared with machining. Multiply by the quantity the buyer expects in the first year or two. If that total is less than the cost of the tool, machine the part and say so. With invented figures: a gear costs ₹180 machined and ₹60 moulded, a saving of ₹120. The tool costs ₹2,40,000. At 1,500 pieces the saving is ₹1,80,000, so machine it. At 2,500 pieces the saving is ₹3,00,000, so the tool pays for itself and a mould is worth quoting.
Put the reason in the quotation. A buyer who asks for a moulded price on two hundred pieces may not know a tool is involved. Where the yearly quantity is large but unproven, quote machined parts for the trial and a separate moulding route for later.
Imagine: a Vadodara shop and the gears that swelled
Imagine an engineering plastics shop in Makarpura GIDC, Vadodara, that stocks rod and sheet and machines bushes, gears and wear strips. A buyer from a Surat textile process house asks on a directory portal for twenty nylon gears, 120 mm across, matching a worn sample. The details are illustrative.
The shop quoted cast nylon the same afternoon and won the order. Within a few weeks the gears jammed. They ran on a dyeing machine, close to hot water all day, and had swollen. The process house blamed the shop and stopped answering calls.
The owner rang the maintenance engineer, not the purchase officer, and asked the use question that had been skipped. He then suggested a grade that takes up far less water, explained why it cost more, and machined two trial gears with clearances set for the running temperature. The trial pair ran, and the process house ordered the rest, though at a higher price per gear than the first quote, and it asked the shop to put the grade in writing on every delivery note. Since then, every directory enquiry for a wear part gets the four questions before any rate goes out, and the use answer is written on the job card.
When to skip the questions, and when to decline
Skip them for a repeat buyer reordering a part you have supplied before without trouble; check the drawing revision and quote.
Decline, politely, when the buyer wants a rating or approval your supplier does not certify. Electrical, food-contact and safety claims sit under rules that differ by product and body and change, so the buyer's engineer and adviser have to settle them. Decline, too, when a buyer wants a moulded price for a handful of pieces and will not hear about machining.
Make "use" a column on the enquiry sheet
Save the four questions as a ready reply on your phone and in your email, and add "use" as a column on the enquiry sheet. No wear part gets a rate until that cell is filled. The four questions are lead qualification at its simplest. How buyers of engineering plastics search and compare is on the plastic manufacturing page. If enquiries are piling up unqualified, tell us what you need.
