Value Collection SIW7X0400-100BX M4 Internal Tooth Lock Washer

Product Description

The VALUE COLLECTION SIW7X0400-100BX is a stainless steel internal tooth lock washer sized for M4 fasteners. It features an inside diameter of 4.3mm and an outside diameter of 8.0mm, with a thickness of 0.5mm. Manufactured from Grade 18-8 austenitic stainless steel to the A2 designation, this washer delivers reliable corrosion resistance and consistent clamping force in bolted assemblies. The internal tooth design bites into both the fastener head and mating surface to resist loosening from vibration or dynamic loading. The uncoated finish leaves the base material properties intact and suits environments where coatings may be incompatible with the assembly process. Installers in HVAC, plumbing, electrical, and industrial service applications use this washer wherever M4 screw connections require positive locking.

This internal tooth lock washer is suited for residential and light commercial equipment assemblies where M4 fasteners are used and vibration resistance is required. Typical applications include panel mounting, equipment enclosures, motor assemblies, and control cabinet hardware. The 18-8 Grade A2 stainless steel construction makes it appropriate for installations exposed to moisture, mild chemicals, or environments where carbon steel hardware would corrode. This washer ships in a minimum order quantity of 100 pieces per package, making it practical for shop stock, service vans, or production-level hardware restocking.

Key Features

• Internal tooth design bites into fastener and mating surface to resist vibration-induced loosening
• Grade 18-8 austenitic stainless steel, A2 designation, for corrosion resistance in wet or chemical-exposure environments
• Inside diameter of 4.3mm fits standard M4 screws and bolts
• Outside diameter of 8.0mm and 0.5mm thickness suit compact fastener assemblies
• Uncoated finish maintains base material conductivity and chemical compatibility
• Minimum order quantity of 100 pieces supports bulk stocking and production use

Compatibility

Designed for use with M4 screws and bolts in assemblies requiring an internal tooth lock washer with a 4.3mm inside diameter and 8.0mm outside diameter.

Installation Notes

Installation is performed by the assembling tradesperson or technician using standard hand tools. Place the lock washer under the fastener head or nut before tightening so the teeth engage both the fastener bearing surface and the workpiece. Ensure the mating surface is clean and free of debris to allow proper tooth engagement. Do not reuse lock washers that have been fully compressed or show flattened teeth, as clamping effectiveness will be reduced.