Screw Factory Dacromet Hex Washer Self-Drilling Screws with EPDM Washer

Product Description

PRODUCT PARAMETER

Flam screws with EPM washers

Hex Flange Self-Drilling Screws with EPM Washers: Overview & Uses
These screws combine a hex flange head (for wrench torque), a self-drilling tip (eliminates pre-drilling), and an integrated EPM (ethylene propylene) washer. The EPM washer, resistant to weather, ozone, and temperatures (-40°C to 150°C), provides a tight seal and anti-vibration grip. Made of galvanized carbon steel or stainless steel, they suit metal/wood fastening.

Applications:

Outdoor Structures: Secure solar panels, metal roofing, or fences (EPM resists rain/UV).
Automotive/Marine: Fasten undercarriage parts or boat panels (seals against corrosion).
HVAC/Plumbing: Attach ductwork or brackets (prevents air/water leaks).

Their all-in-one design saves time, ensures tight seals, and excels in harsh, vibration-prone environments.

Thread Spec			ST2.9	ST3.5	(ST3.9)	ST4.2	ST4.8	(ST5.5)	ST6.3
P	pitch		1.1	1.3	1.3	1.4	1.6	1.8	1.8
a	Max		1.1	1.3	1.3	1.4	1.6	1.8	1.8
c	Min		0.4	0.6	0.6	0.8	0.9	1	1
dc	Max		6.3	8.3	8.3	8.8	10.5	11	13.5
	Min		5.8	7.6	7.6	8.1	9.8	10	12.2
e	Min		4.28	5.96	5.96	7.59	8.71	8.71	10.95
k	Max		2.8	3.4	3.4	4.1	4.3	5.4	5.9
	Min		2.5	3	3	3.6	3.8	4.8	5.3
kw	Min		1.3	1.5	1.5	1.8	2.2	2.7	3.1
r	Max		0.4	0.5	0.5	0.6	0.7	0.8	0.9
s	Max		4	5.5	5.5	7	8	8	10
	Min		3.82	5.32	5.32	6.78	7.78	7.78	9.78
dp			2.3	2.8	3.1	3.6	4.1	4.8	5.8
Drilling range (plate thickness)			0.7~1.9	0.7~2.25	0.7~2.4	1.75~3	1.75~4.4	1.75~5.25	2~6
Lg (Min)			-	-	-	-	-	-	-

ABOUT US

LONGSHI FASTENERS MANUFACTURING CO.,LTD.,

Longshi Fastener Manufacturing Co., Ltd., founded in 2008, is located in Shahe City, Hebei Province, close to the country's largestLarge fastener industrial cluster - Yongnian standard parts Industrial Park. The company headquarters covers an area of 21 thousand square meters, the annual output value of 200 million yuan, with more than 200 employees, with domestic More than 100 sets of advanced production equipment. It is a "manufacturing + service" type enterprise integrating fastener production, intelligent warehousing and e-commerce sales. The company's construction of the sea screw e-commerce park is located in Yongnian District, Handan City, Hebei Province, covers an area of 45 acres, the park planning and construction of office area, production area, packaging area, storage area, etc., to provide fastener production, packaging, warehousing, e-commerce sales and other services. Longshi mainly produces high quality and high strength fasteners, and "Longshi" screws have become a well-known brand in the industry. Longshi always adhere to quality first, reputation first. From raw material procurement, design and development, production and processing to products strict quality control is implemented in every link of quality testing and sales to win the recognition of our customers. The company has established standardized product testing laboratories and quality testing processes and standards to ensure that products strictly comply with national standards.

FAQ

Q1: What is your minimum order quantity (MOQ)? Do you charge extra for small orders?
100 pieces MOQ (most peers require 1,000+), no price premium for small orders. First-time customers for cross-border e-commerce/trade get free samples.
Q2:Do you support custom orders? How long does the customization process take?
Longshi Advantage: 8-dimensional customization (material, specification, surface treatment, etc.), with 3D design drawings + process plans.
Q3: What if an item is out of stock?
Stockout rate <0.1% (peers: 10+%), with real-time inventory monitoring. For extreme stockouts, free upgraded alternatives are provided (peers often leave clients waiting indefinitely).
Q4: Do you provide technical support, such as installation guidance or drawing optimization?
Dedicated 1v1 engineer team offering free technical support.
Q5:Can I visit your factory or arrange a factory audit?
Support online factory tours (real-time video of production lines/laboratories) and offline visits (pick-up service available).