How to Specify Pan Head Phillips Screws: A Real RFQ Walkthrough

Pan head Phillips screws are one of the most-quoted items in our inbox — and also one where vague RFQs cost buyers the most time. Based on a recent real inquiry we quoted, here is how to specify a pan head Phillips screw so a factory can price it accurately on the first pass.

A real RFQ, line by line

A recent customer inquiry specified a pan head Phillips screw as follows:

• Size: M5 × 20 mm
• Material: SWRCH 7A cold heading steel (the matching hex nuts on the same order were SWRCH 6A)
• Finish: blue zinc plating, 6 µm minimum thickness

That is a complete, quotable spec in three lines. The two details that most RFQs leave out — and that this buyer got right — are the material grade and the minimum plating thickness.

Why the material grade matters

“Carbon steel” alone is not enough. SWRCH grades are wire rods drawn specifically for cold heading: the head of a pan head screw is formed by displacing metal, not cutting it, so the wire must flow without cracking. Naming the grade (SWRCH 6A, 7A, etc.) tells the factory exactly what wire to buy and removes a whole round of clarification emails.

Why “6 µm minimum” beats “zinc plated”

Plating thickness is where corrosion performance actually lives. A minimum-thickness callout is verifiable: we measure zinc coating thickness on a coating thickness gauge as part of standard inspection, and plated batches are salt-spray tested to verify the coating’s rust protection. “Blue zinc” (blue-white passivate) also pins down the appearance, which matters when the screw is visible on the finished product.

How these screws are made and checked

At Guangdong Taiyuanfeng (TYF), pan head Phillips screws run on multi-station cold heading machines (wire diameter capability φ2.0–15.8 mm), then thread rolling and plating. Inspection on this type of part typically includes:

• Optical sorting — machine-vision inspection of every piece for dimensional and surface defects (resolution ≤0.01 mm on diameter and length), which is what makes high-volume orders practical without sampling risk;
• Coating thickness gauging for the zinc layer;
• Recess and thread checks against the drawing on an optical projector.

Checklist for your next pan head Phillips screw RFQ

• Thread size and length (e.g., M5 × 20)
• Material grade (SWRCH series for cold-headed carbon steel)
• Finish + minimum plating thickness (e.g., blue zinc, 6 µm min)
• Phillips recess size if your driver bits are fixed
• Application notes — what the screw goes into, indoor or outdoor

Send us a spec in this format and we will return a firm quotation. If you only have a sample or a photo, that works too — we will reverse the spec for you.