ARP 12-Point Nut - M12 x 1.25, 16 mm Socket, Black Oxide

ARP 301-8318 is a single 12-point nut in M12 x 1.25 thread, finished in black oxide and sized for a 16 mm socket. A 12-point head gives a wrench or socket twice the engagement positions of a hex, which matters when clearance around a stud is tight and a full swing is not available. ARP's other M12 x 1.25 12-point nuts take a 14 mm socket, so the 16 mm size identifies this as the larger collar version. It ships as one nut rather than a set.

Specifications

Shipping

• In-stock orders placed before 3 PM EST ship the same day — everything else ships within 24 hours.
• Standard, expedited, and overnight options at checkout.
• Oversized items ship by freight and take longer.
• Backordered items ship as soon as stock lands — contact us for lead times.
• International orders: prices do not include VAT, duties, or import fees. Your country charges these at import and they are the buyer’s responsibility.

Returns

• 30-day returns on new, uninstalled items in original packaging with all hardware.
• Standard returns: 8% restocking fee, buyer pays return shipping. Both waived if the item is defective or we made the error.
• Installed or used parts can’t be returned — confirm fitment before you install.
• Special orders and custom items are final sale.
• Email us for return authorization before shipping anything back.

Full details: Shipping Policy · Refund Policy