1629831 Hexagon Screw | Genuine Volvo Penta Part

🔧 Product Description

Hexagon screw supplied as a standard threaded fastener in the 9/16" UNF x 51 mm size, used as a service replacement item where that thread and length are specified. As a general-purpose fastener it is not tied to a single engine or drive model, and it is the current replacement for several earlier fastener and anchorage part numbers. Net weight is approximately 0.092 kg.

⚙️ Key Features

• OEM Volvo Penta part number 1629831
• Hexagon head screw, 9/16" UNF thread, 51 mm length
• Net weight 0.092 kg
• Supersedes earlier part numbers 1626181, 1698730, 1697966 and 1698731
• Standard threaded fastener supplied as an individual service item
• Engine type: Application dependent
• Also supersedes Volvo part number 1697217

🔌 Function

Provides a threaded clamping fastener that secures two or more components together at a specified torque. Its 9/16" UNF thread and 51 mm length determine the joint and grip depth it is intended for.

⚠️ Common Signs of Failure

• Rounded, burred or damaged hexagon head preventing correct socket engagement
• Stripped, galled or cross-threaded threads that will not hold torque
• Corrosion, pitting or seizure making removal difficult
• Stretched or necked shank after over-torquing, causing loss of clamping force
• Repeated loosening of the joint or components working loose in service

🛠️ Service Notes

• Check the length, thread and strength grade of the replacement against the screw you removed — engine fasteners are chosen for a specific clamp load, and a longer or softer screw is not a substitute
• Clean the threads in the component and make sure the mating faces are clean and flat before assembly; dirt, paint or old sealant in a joint feels like tightness and leaves the joint loose
• Tighten to the torque figure and the tightening sequence given in the workshop manual for your engine, working up progressively rather than pulling each screw down in one go
• Use thread locking or sealing compound only where the manual calls for it, and renew the locking washer, tab washer or nut that works with the screw
• Renew rather than reuse screws that are corroded, thread-damaged or visibly stretched, and any screw the manual tightens by torque-plus-angle

🔄 Supersession & Cross Reference

OEM Supersession Chain

• 1629831 → Supersedes 1626181

OEM / Related Numbers

• 1698730 earlier number superseded by this part
• 1697966 earlier number superseded by this part
• 1698731 earlier number superseded by this part
• 1626181 earlier number superseded by this part

📦 Condition

• Genuine Volvo Penta part
• Brand new
• Supplied in original or equivalent packaging