M3 Button Head Hex Screws, 12.9 Grade Steel (10pcs)

M3 button head screws in 12.9-grade steel with a hex socket drive, sold in bags of 10 in one length. Ten lengths from 6 mm to 30 mm cover most M3 jobs on a 5-inch or larger quad: motor mounting, arm and plate fixings, standoffs and through-bolting 30.5x30.5 flight-controller stacks.

Key features

• 12.9 is the highest strength class for metric steel screws, so these resist stretching and snapping when tightened firmly
• Button head gives a lower profile than a socket cap head
• Hex socket drive for a hex key or driver

Specifications

• Thread: M3 metric
• Head: button head, hex socket
• Material: 12.9-grade alloy steel
• Lengths: 6, 8, 9, 10, 12, 16, 18, 20, 28 and 30 mm, measured from under the head to the tip
• Pack: 10 screws of one length

For motor mounting, choose a length that passes through the arm and engages the motor base by a few millimetres without reaching the windings — a screw that touches the stator can short the motor. The 28 and 30 mm lengths suit bolting a 30.5x30.5 stack through the frame. 12.9 alloy steel is not stainless, so dry the hardware after flying in wet grass, and use a medium-strength threadlocker on motor screws.