Still Guessing What "4×10 PW A H C (+)" Actually Means?

Every week our sales team hears the same thing from new European buyers: "I got a quote full of letters and numbers — what does it all mean?" If you've ever stared at a screw code and guessed, this guide is for you. As a screw factory, we'll show you how to read any spec sheet like our own engineers do.

The 7-part code, decoded

A typical screw code looks like 4 × 10 PW A H C (+). Each segment tells you one property:

1. Diameter — metric (2–20 mm) or inch (#2 to 3/4").

1. Length — metric (5–120 mm) or inch.

1. Head type — P flat, PW flat + washer, H hex, HW hex + washer, F countersunk, C cylindrical, T large flat, V mushroom.

1. Thread / tail — A & B self-tapping, M machine, BTT / CCT / PTT / STT tri-lobe self-tapping for hard substrates.

1. Heat treatment — H treated (high strength) or N untreated.

1. Surface finish — Zn white zinc, C color zinc, Ni nickel, Cu bronze, P phosphating, etc.

1. Remarks — drive type (+ cross, – slot, H hex socket, PZ pozidriv), material (SUS stainless, Cu brass) and grade (8.8 / 10.9 / 12.9).

Worked example: 4-0.7×70 P M ± tooth length 35 → Ø4 mm, 0.7 mm pitch, 70 mm long, pan head, machine thread, ± drive, 35 mm threaded length.

Why this matters for your order

When you read the code correctly, you stop over-paying for specs you don't need — and you catch suppliers who quietly downgrade finish or heat treatment. That's exactly the kind of mistake that surfaces only after installation.

We're a screw factory supplying European distributors and OEMs. We accept custom orders — send us your drawing, sample, or even a photo of the code, and we'll match it, prototype it, and quote it. Every batch ships with an MTC and salt-spray test report on request.

Contact us now for samples: support1@tianyufasteners.com. Explore our offerings at www.tianyufasteners.com.

Procurement Q&A

Q: Can you produce screws to our own code or drawing? A: Yes. As a factory we accept custom specifications — send your drawing, sample, or even a photo of the spec code, and we'll match it and provide prototypes before bulk production.

Q: Do you provide MTC and salt-spray test reports? A: Yes. We issue a Material Test Certificate for every batch and can provide neutral salt-spray test reports (up to 1000+ hours depending on finish) on request.

Q: What finish do you recommend for outdoor / high-humidity European projects? A: For outdoor or coastal use we recommend nickel plating or our salt-spray-tested anti-corrosion coating; standard zinc plating is fine for indoor dry applications. We'll advise based on your actual environment.

Q: What are your MOQ and lead times for European shipments? A: Standard items start from a low MOQ; fully custom runs are quoted case by case. Typical ex-works lead time is 15–30 days, with DAP/DDP delivery to major EU ports available. Contact us with your volume for an exact quote.