DIN 436 Square Washer for Wood Construction — A2 Stainless Steel (SUS304), Whitened & Passivated

FULLERKREG DIN 436 square flat washers are manufactured to DIN 436 standard in A2 stainless steel (SUS304 / 1.4301 / 0Cr18Ni9) with a whitened and passivated surface finish. DIN 436 square washers feature a large square external shape rather than the conventional round profile, providing a significantly larger bearing area that distributes bolt load over a wider surface — essential for wood construction, timber framing, and applications at risk of seismic activity where pull-through resistance is critical. The square profile also prevents rotation during tightening. A2 stainless steel provides excellent general corrosion resistance, non-magnetic properties, and food-safe compliance — ideal for outdoor timber structures, marine-adjacent construction, and food-industry woodwork.

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Product Highlights

• Standard: DIN 436 (Square Flat Washer for Wood Construction)
• Material: A2 Stainless Steel (SUS304 / 1.4301 / 0Cr18Ni9)
• Surface Treatment: Whitened & Passivated
• Size Range: M10 – M52
• Profile: Square — large bearing area, prevents rotation, distributes load over wide surface
• Primary use: Wood construction, timber framing, structural bolting, seismic applications
• Pull-through resistance: Large square area prevents bolt head pull-through in timber
• Non-magnetic, non-sparking
• RoHS & REACH Compliant

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Dimensional Specifications — DIN 436 Square Washer, A2 Stainless

All dimensions in millimeters (mm). Per DIN 436.

For Thread	d1 min	d1 max	a nom	a min	a max	h nom	h min	h max
M10	11	11.43	30	28.7	30	3	2.4	3.6
M12	13	13.5	40	38.4	40	4	3.4	4.6
M16	17.5	18.2	50	48.4	50	4	3.4	4.6
M20	22	22.84	60	58.1	60	4	3.4	4.6
M22	24	24.84	70	68.1	70	5	4	5
M24	26	26.84	80	78.1	80	5	4	5
M27	30	30.84	90	87.8	90	5	4	5
M30	33	34	95	92.8	95	6	5	6.8
M33	36	37	100	97.8	100	6	5	6.8
M36	39	40	110	107.8	110	6	5	6.8
M39	42	43	120	117.5	120	8	6.8	8
M42	45	46	130	127.5	130	8	6.8	8
M45	48	49	140	137.5	140	8	6.8	8
M48	52	53.2	150	147.5	150	8	6.8	8.8
M52	56	57.2	160	157.5	160	10	8.8	11.2

All dimensions in mm per DIN 436. d1 = inner hole diameter; a = square side length; h = washer thickness. Tolerances per DIN 436.

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DIN 436 Square Washer vs. Standard Round Washer — Key Differences

Feature	DIN 436 (Square)	Standard Round Washer (DIN 125)
Shape	Square	Round
Bearing area	Much larger — full square surface	Standard annular area
Pull-through resistance	High — ideal for timber	Standard
Rotation prevention	Yes — square profile locks in timber grain	No
Primary use	Wood construction, timber framing, structural	General bolted assemblies
Size range	M10–M52	M1.6–M64

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Material & Mechanical Properties — A2 Stainless Steel (SUS304)

Property	Value
Material Grade	A2 / SUS304 / 1.4301 / 0Cr18Ni9
Cr Content	17.5 – 19.5%
Ni Content	8.0 – 10.5%
Surface Treatment	Whitened & Passivated
Magnetic	Non-magnetic (austenitic)
Operating Temperature	-196°C to +300°C
Corrosion Resistance	Excellent — atmospheric, fresh water, mild chemicals
RoHS / REACH	Compliant

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Application Scenarios

• Timber frame construction — large square bearing area prevents bolt pull-through in wood
• Outdoor wooden structures — decking, pergolas, bridges, boardwalks requiring corrosion resistance
• Seismic-resistant construction — DIN 436 specifically designed for applications at risk of seismic activity
• Glulam & engineered timber connections — structural bolting in engineered wood products
• Marine & coastal timber structures — A2 stainless for salt air environments
• Agricultural buildings & barns — large washers for heavy timber connections
• Playground & park equipment — food-safe, non-toxic, corrosion-resistant

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Product Photo Gallery

FULLERKREG DIN 436 Square Washer, A2 Stainless Steel:

[ Photo 1 ]

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[ Photo 3 ]

[ Photo 4 ]

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Why Choose FULLERKREG?

• 🏭 Direct manufacturer — factory in China, no middlemen
• 📐 Strict DIN dimensional control — 100% inspection on critical dimensions
• 🌍 Global export experience — serving distributors in Europe, North America, Southeast Asia
• 📦 Flexible MOQ — small trial orders and large bulk shipments both welcome
• 📋 Full documentation — material certs, RoHS declarations, test reports available
• ⚡ Fast lead times — standard sizes in stock, ready to ship

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Frequently Asked Questions

Q: What is DIN 436?
A: DIN 436 specifies square flat washers for wood construction. The large square profile provides a much greater bearing area than standard round washers, preventing bolt head pull-through in timber and distributing load over a wider surface. Specifically designed for timber framing and seismic applications.

Q: Why use a square washer instead of a round washer for wood construction?
A: The square profile provides a significantly larger bearing area, greatly improving pull-through resistance in timber. The square shape also prevents rotation during tightening and locks into the wood grain, maintaining bolt tension more effectively than round washers.

Q: What size range does DIN 436 cover?
A: DIN 436 covers M10 through M52, with square side lengths from 30mm (M10) to 160mm (M52) and thicknesses from 3mm to 10mm.

Q: Is A2 stainless steel suitable for outdoor timber construction?
A: Yes. A2 (SUS304) provides excellent resistance to atmospheric corrosion, rain, and mild salt air. For highly aggressive marine environments (direct seawater contact), A4 (SUS316) would be recommended.

Q: Do you provide material test certificates?
A: Yes. Mill certificates, chemical composition reports, and dimensional inspection reports are available upon request.

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