M4 Stainless Steel Flat Washer A2 DIN125 50-Pack

M4 Stainless Steel Flat Washer — A2 DIN125, 50-Pack

M4 A2 stainless steel DIN125 flat washers distribute the clamping load of M4 screws and bolts over a larger surface area, preventing pull-through in soft materials, protecting surface finishes, and providing a smooth bearing surface for nut tightening. The larger M4 washer is essential for structural bracket assembly, aluminium extrusion mounting, and any application where M4 clamping force would damage the substrate without load distribution.

Key Specifications

Parameter	Value
Thread Size (fits)	M4
Inner Diameter (ID)	4.3mm
Outer Diameter (OD)	9mm
Thickness	0.8mm
Material	A2 Stainless Steel
Standard	DIN125 / ISO 7089
Quantity	50pcs per pack

Why Choose M4 A2 Stainless Flat Washers?

• Load distribution — 9mm OD spreads M4 clamping force over a larger area; prevents pull-through in plastic panels, thin sheet metal, and soft materials
• Surface protection — smooth washer face protects anodised aluminium, painted surfaces, and plastic from M4 screw head damage during tightening
• A2 stainless steel — corrosion-resistant; will not rust or stain electronics enclosures and outdoor equipment
• DIN125 standard — internationally specified; compatible with all M4 screws, bolts, and nuts
• 50-pack quantity — practical workshop stock for prototyping and production

Typical Applications

• Aluminium extrusion bracket and corner bracket assembly (M4 bolt + washer)
• Electronics enclosure panel mounting with M4 bolts
• Robotics chassis and structural bracket assembly
• CNC machine axis and gantry structural assembly
• NEMA 23 stepper motor mounting (M4 mounting holes)
• Industrial equipment panel and bracket mounting

Compatible With

• All M4 machine screws, cap screws, and bolts
• M4 hex nuts, nyloc nuts, and flange lock nuts
• M4 split lock washers (used together for vibration resistance)
• M4 T-slot bolts for aluminium extrusion assembly
• 9mm OD fits standard M4 counterbore dimensions

Package Contents

• 50× M4 A2 stainless steel DIN125 flat washers

Frequently Asked Questions

Q: What is the outer diameter of an M4 flat washer?

A: M4 DIN125 flat washer OD is 9mm, ID is 4.3mm, thickness is 0.8mm. These are standard dimensions compatible with all M4 screws and bolts.

Q: Do I need a flat washer for aluminium extrusion T-slot assembly?

A: A flat washer is recommended under the bolt head when mounting brackets to aluminium extrusion, especially for anodised extrusion where the bolt head could damage the anodised surface. It also helps distribute the clamping load across the bracket face.

Q: Can I use M4 flat washers with M3 screws?

A: No. M4 flat washers have a 4.3mm ID which is too large for M3 screws (3mm diameter). The washer would not be retained by the M3 screw head. Always match the washer size to the screw size.

Enjoy free standard shipping on all orders over $199 USD. Orders are processed within 1–2 business days.

Not satisfied? Return any item within 90 days of purchase for a full refund or exchange. Items must be in original condition.

We are committed to quality, reliability, and customer satisfaction. Every product is carefully selected and tested to meet the highest standards.