M4 Stainless Steel Split Lock Washer A2 DIN127 50-Pack

M4 Stainless Steel Split Lock Washer — A2 DIN127, 50-Pack

M4 A2 stainless steel DIN127 split lock washers provide vibration-resistant fastening for M4 bolts and screws by using spring tension to maintain clamping force under vibration and dynamic loads. The split ring design bites into both the nut and the bearing surface, resisting rotation and preventing loosening in motor mounts, structural brackets, and industrial equipment fastening.

Key Specifications

Parameter	Value
Thread Size (fits)	M4
Inner Diameter (ID)	4.1mm
Outer Diameter (OD)	7.6mm
Thickness	1.0mm
Material	A2 Stainless Steel
Standard	DIN127 / ISO 7090
Quantity	50pcs per pack

Why Choose M4 A2 Stainless Split Lock Washers?

• Spring tension anti-loosening — split ring maintains clamping force as the joint settles under vibration and thermal cycling
• Bite-in anti-rotation — sharp split ends bite into nut and bearing surface, resisting rotation under vibration
• A2 stainless steel — corrosion-resistant; will not rust or weaken in electronics enclosures and outdoor equipment
• DIN127 standard — internationally specified; compatible with all M4 screws, bolts, and nuts
• 50-pack quantity — practical workshop stock for prototyping and production

Typical Applications

• NEMA 23 stepper motor mounting on CNC machines (vibration-prone, M4 mounting holes)
• Aluminium extrusion bracket assembly in vibrating equipment
• Robotics actuator and servo bracket mounting (dynamic loads)
• Industrial machinery and equipment fastening (vibration environment)
• Electronics enclosure panel mounting in vibrating equipment
• CNC machine axis and gantry structural assembly

Compatible With

• All M4 machine screws, cap screws, and bolts
• M4 hex nuts and nyloc nuts
• M4 flat washers (use flat washer first, then split lock washer, then nut)
• Installation order: surface → flat washer → split lock washer → nut

Package Contents

• 50× M4 A2 stainless steel DIN127 split lock washers

Frequently Asked Questions

Q: What is the correct installation order for M4 split lock washers?

A: Correct order from surface outward: (1) flat washer DIN125 against the surface, (2) split lock washer DIN127, (3) hex nut. The flat washer protects the surface; the split lock washer provides spring tension and bite-in anti-rotation between the nut and flat washer.

Q: Should I use split lock washers or nyloc nuts for NEMA 23 motor mounting?

A: Both are effective. Split lock washers are reusable and allow easy adjustment; nyloc nuts provide more reliable anti-loosening for high-vibration applications. For CNC machine motor mounts subject to significant vibration, nyloc nuts are generally preferred. For lighter-duty applications, split lock washers are a practical and economical choice.

Q: What is the thickness of an M4 split lock washer?

A: M4 DIN127 split lock washer thickness is 1.0mm. This adds 1mm to the fastening stack height compared to a flat washer (0.8mm). Account for this when calculating total stack height in tight assemblies.

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