Hex Washer Head Self-Drilling Screw with EPDM Washer

Overview

The workhorse of metal roofing and wall cladding. An indented hex washer head takes a magnetic nut setter, and a bonded EPDM washer on a steel backing seals the fixing hole against rain while spreading clamp load across the sheet.

We cold-head C1022 steel, roll the thread, mill the drill point, then carburise for a hard case over a tough core. Choose 14 or 16 mm washers, and zinc, yellow zinc or ceramic coatings to match the exposure.

Applications

Metal roofing and wall cladding
Steel purlins and girts
Gutters and flashing

Used in these projects

Steel warehouse with sandwich panel roof and walls

Key features

Drill, tap and seal in one step
Steel-backed EPDM washer stops leaks and sheet dimpling
Indented head for positive nut-setter grip
Head marking and colour-matched heads on request

Specifications

Typical values. Every dimension, hardness and coating is confirmed in writing with your quotation.

Hex Washer Head Self-Drilling Screw with EPDM Washer specifications
Standard	DIN 7504 K
Diameter	ST4.2, ST4.8, ST5.5, ST6.3 (#8–#14)
Length	13–200 mm
Material	C1022 carbon steel, case hardened
Drill point	#1, #2, #3, #4, #5
Washer	Bonded EPDM, 14 / 16 mm OD
Finish	Zinc, yellow zinc, nickel, Dacromet, ceramic coating
MOQ	50,000 pcs per size
HS code	7318.14 / 7318.12 (by type)

Buying guide

Applies to all self-drilling screws.

Match the drill point to the steel

Point #1 suits sheet up to 0.9 mm, #2 up to 2.8 mm, #3 up to 4.4 mm, #4 up to 5.25 mm and #5 up to 12.5 mm. The drill flute must clear the full material thickness before the thread engages, or the screw will jam and snap.

Choose a washer for weather-tight joints

Roofing and cladding screws take a bonded EPDM washer (14, 16 or 19 mm) under an indented hex washer head. The rubber seals the hole; the steel backing spreads the load so the sheet does not dimple.

Specify corrosion class, not just "zinc"

Electro-zinc gives roughly 72 h to white rust in salt spray. For exterior roofing ask for ceramic coating (500–1,000 h) or AS 3566 Class 3/4 coatings, and for coastal sites move to bi-metal stainless screws.

Ordering

Packing and delivery

Standard terms for this product. Tell us if your market needs something different.

PackingSmall boxes, buckets or 20–25 kg cartons on fumigated pallets; private label available.

Lead timeSamples in 7 days; production 25–35 days after deposit.

PaymentT/T 30 % deposit, 70 % against B/L copy, or L/C at sight.

ShippingFOB Shanghai or Ningbo, CFR or CIF to your port.

Questions about this product

What is the difference between self-drilling and self-tapping screws?

A self-tapping screw forms threads in a pre-drilled hole, while a self-drilling screw drills its own hole first using a drill-shaped point. Self-drilling screws save a step on metal-to-metal joints.

Which standards do your self-drilling screws follow?

We produce to DIN 7504 (K, M, N, P, O forms), ISO 15480–15483 and AS 3566.1/.2, and to customer drawings for non-standard lengths, heads or head marks.

What is your MOQ for self-drilling screws?

Standard sizes start at about 500 kg or 50,000 pieces per size. Mixed sizes can share one container, and stock items can ship in smaller lots.

Self-Drilling Screws