Wacker Neuson 5100064409 Screw M8x25 DIN7991

The Wacker Neuson Screw M8x25 DIN7991 is a genuine OEM fastener designed for the PT6Y and PT6YT series water pumps. As a direct OEM component, is manufactured to the exact DIN7991 countersunk hex socket standard, ensuring correct head geometry, thread engagement, and torque retention in every application. Verified fitment covers the PT6Y, PT6YT, PT6Y-AU, and PT6Y EPA T4 models, so you can order with confidence knowing this screw matches your machine's original specification. Sourcing the correct fastener matters — using an incorrect screw in a pump assembly can compromise clamping load and lead to leaks or structural loosening under vibration.

Key Features

• DIN7991 Countersunk Profile: — Correct flat-head geometry allows the screw to sit fully flush, maintaining proper surface contact and load distribution within the pump assembly.
• Genuine OEM Thread Accuracy: — M8x25 dimensions are held to OEM tolerance, ensuring full thread engagement without cross-threading or under-torque risk on reassembly.
• Direct OEM Replacement: — Drops straight into the same mounting position as the original, with no rework or adjustment needed to the surrounding components.
• Broad PT6Y Series Coverage: — Fits PT6Y, PT6YT, PT6Y-AU, PT6YT-IN, and PT6Y EPA T4 models, making it the right choice across the full PT6Y pump family.
• Vibration-Resistant Clamping: — Correct fastener spec maintains clamping integrity during pump operation, preventing loosening that can allow housing movement or seal failure.

A countersunk socket head screw such as the M8x25 DIN7991 is used in assemblies where the fastener head must sit flush with or below the surrounding surface, preventing interference with mating components or covers. In a pump application, these screws secure housings, covers, and internal components where consistent clamping force is critical to maintaining seals and alignment under continuous vibration and load. When a fastener of this type is damaged, missing, or replaced with an incorrect substitute, it can result in inadequate clamping, which allows movement between components, accelerates wear on gaskets and seals, and can ultimately cause fluid leaks or structural failure of the assembly.

Part Details

Compatibility & Fitment

Verify Before You Order

Fitment is machine-number and revision-specific; always confirm your model and serial number against the fitment list.

Why Buy From DHS Equipment

Every part is verified against the manufacturer's part number before it ships, so what you order is what arrives. We carry parts from leading OEM brands and our own DHS Quality Parts line of professional aftermarket components. Need help finding the right part? Our team is available to confirm compatibility whenever you need it. Orders are processed fast to keep your jobs on track. We don't just sell parts. We keep you jobsite ready.

Questions? Contact our team at [email protected] or 866-611-9369 — DHS Equipment is here to help you maintain peak performance.